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A 1.8L 412 engine build thread
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raygreenwood
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Joined: November 24, 2008
Posts: 14837
Location: Des moines Iowa
raygreenwood is offline 

PostPosted: Fri Feb 02, 2018 2:16 pm    Post subject: A 1.8L 412 engine build thread Reply with quote

Build thread for a 1.8L type 4, engine for a 1974 VW 412

Ok….this is overdue to start a build thread. I will try not to get too wordy before the pictures start. Wink

I have been working steadily on the main parts of this engine and taking lots of pictures and measurements. This build is for a gentleman friend who will remain anonymous until such time he chooses to announce his identity…no…it’s not for a foreign national in trade for illegal weapons technology….not that I am “totally” averse to that! Wink

The parts list so far:

EA series late case (appears to be from a 412 or 914)

1.7L/1.8L 66mm crankshaft ground .010” undersized (very nice crank)

NOS Kolbenschmidt shallow dish pistons (appear to be early to mid-90’s)

Kolbenschmidt cylinders (possibly COFAP production, definitely no CIMA tags near base)

1.8L rods (round enough shape that they could actually be used without resize but will be resized)

New Metal Leve rod bushings (double thrust)

NOS Kolbenschmidt (late 80’s to early 90’s) .010”/.010” main and rod bearings

Web #73 camshaft with gear and lifters

Stock pushrods for now. We will know when setting the geometry whether they will work but they are straight.

1.7L rocker arms (these will be ground .060 on the underside for swivel feet)

Mahle/Wizeman OEM Porsche Swivel feet adjusters (very nice!)

Type 4 store 1.8L solid rocker spacer kit.

Cylinder heads: Part # 021 101 371 S.
These are1.8L rebuilt about 10 years ago by a reputable type 4 house. These heads are very nice but have a couple of issues. They were rebuilt VERY well….but rebuilt to carbed “Bus” specifications. They have 39mm x 33mm valves instead of the proper 41mm x 34mm valves of a 914 or 412 1.8L.

The chambers also have a small step of about .032” cut into the heads which is not correct or ideal. While this is technically not an issue for a bone stock rebuild as it is/was commonly done by some head builders knowing that during a proper rebuild the factory head gasket will be left out and this pretty much keeps compression at stock.

But….one of the issues with the 1.8L in the 412 and 914 was mediocre performance and hot running due to under compression for emissions (and the camshaft which was D-jet oriented and resulting fuel tuning didn’t help any). What could have and should have been a better motor than the 1.7L…was made to be ‘less than” by this factor.

Since we are going to a better cam that stays with the stock lobe center and timing range…but is definitely an improvement (Web #73) I am going to work toward getting at least 8.0:1 compression.

While I could easily work with this small step, the size of the 1.8L chambers plus the 7cc piston dish can make getting 8.0:1 or better a little difficult. I would rather have a very tight deck and do all of the work at the case ends with shims.

Work currently in progress:

Heads:

The shop working on these is running a little behind at this date (1-29-2018). I am hoping to get a complete update by tomorrow.

I know that getting get quality valves of the proper stem length is slowing them down slightly. I may opt to upgrade them to 42mm x 36mm…which I have done on 1.8L builds before and it tunes out quite well. I can get pretty damn good quality valves in 42mm X 36mm right now (Intervalve brand) It definitely wakes up a 1.7L with a web #73…but the compression MUST be there.

I will be speaking directly to Manley and Ferea tomorrow to see if they have any “914” valves not listed in their catalog.

Connecting Rods:

I have paused work on the rods for the moment since right before Christmas because I want to send them to the shop with the crank and rod bearings….which is the proper way to go when resizing rods and setting side clearance. I am waiting because I wanted to test fit the crank to the case with the main bearings first before the crank leaves my hands.

The case main bores measure nice and round with the dial bore gauge and the crank journals measure just about spot on to where they should for a .010” undersized grind (I will post numbers and measurement maps shortly)…..but we all know that there is always some variation in the size and fit of bearings ….as I found out with the first set of rods and bearings I test fitted to the crank. It left me around .0005”-.0008” larger than I would like to have on the oil tolerance. A different set of NOS bearings corrected this.

So…fitting the main bearings to the case with the crank for both a dial bore gauge check and a plastigauge backup check and then test fitting cam bearings and cam to check lash…are key…but the case must be clean to do this with parts this valuable.

So…

Cleaning and deburring the crankcase:

A lot of this was done a couple weeks ago and I have posted a few pictures but will post a lot more today as this build thread begins. I am getting into this in some detail…because a lot of people ask how to clean their cases professionally…or at least as good as professional at home.

1. if its greasy…really greasy (which this one was not)…it pays to either take it to the car wash or have a basic pressure washer and parts washer at home. For the internal parts…really a parts washer is almost indispensable.

2. You can deburr as well as anyone…with care…with basic hand tools that I will list.

3. Many machinists and me included say it is really helpful and ideal…to pull the galley plugs and take the case to a machine shop to first run through a heated aluminum vat and then into a jet washer. However…in reality…no jet washer anywhere will clean the galleys as well as I show here because it cannot concentrate on them.

Plus…with hot water and the right chemicals and tools …and some attention and elbow grease…you can clean a case just as good or better than a jet washer.

The plastic laundry sink with legs that I use for stuff like this… that fits a complete engine case in it almost deep enough to submerge it was about $30-40 at Lowes. I put a standard water faucet valve on the bottom for about $4. It is 21” wide, 20” long and 13-14” deep. The case halves submerged when laid back at about a 45° angle. They will just about lay down in the sink.

At first glance and measurement…this is a nice straight case, fairly clean as old cases go. As I started working on it….I realized it has more casting flash than almost any case I have worked on in a while. Nothing that will hurt its effectiveness…and it could have just been used as is….but also a lot of casting flash inside and quite a bit of while corrosion both inside and out.

This case was stored well but it’s has a LOT of hot to cold and cold to hot condensation corrosion from age. That white corrosion inside can hide a lot of grit…and…as someone noted in a conversation last week…when there is so much flash that you really cannot “run a rag over it” without getting a pound of lint and snags….it should be cleaned up if for no other reason than to make it more crack resistant and less “knuckle skinning”

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The other side of the case was not quite as bad. You can see my stainless wire brushing attempts which removed the top coating of dirt no problem but left scale.

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A little of this is just dirt. But that dirt collected moisture and almost everywhere there is dirt it has whitish/yellowish scale underneath. No point in showing it from every view…just know that its everywhere.

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The bottom case fins on both sides had this flash.

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This is just getting into it. A lot of the big flashing is gone and you can see some light scratches from scotch brite. Those will be wire wheeled away and polished.

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It was at this point that I removed enough gunk that I discovered the case hieroglyphics I mentioned last week. I will include those later in this thread.

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A lot if this may seem excessive…but most cases have a small amount of “crazing” or fine spider web raised mold shrinkage marks. This one had them too but they were roughly 2X the height of my other cases.

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Working the nooks, crannies and flashing lines

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You can see some of the hard flash lines on the left side of the left picture that have been erased in the right picture

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There was only some flashing in these areas. Mostly just getting rid of corrosion scale mixed with dirt.

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NOTE: do not be alarmed at the mottled look. Most of that is due to the bright lights and the slightly more or less polished areas. After this initial washing/cleaning…..which is primarily to get it squeaky clean enough to fit machined parts and bearings into….there will be a final wipe over and polish to make the surface uniform….and some of that will be taken care of during the chemical washing…and the rest…in very short order will develop the natural aluminum patina when its rinsed with hot distilled water and left to air dry.

The tools I used:

Somewhere my favorite slide hammer for removing case galley plugs has gone missing. The little crappy harbor freight cheap $12 half pound slide hammer is nearly worthless…and larger cheap Chinese slide hammers are not around like they used to be.
Everyone from Harbor Freight to Northern tool now only offers them in “kits” with blow molded cases and lots of accessory implements I do not need….and not for $45. So…I made this from an old 10lb dumbbell I cut in half and drilled a hole through, put in a carriage bolt from the hardware store with a 1/4-20 hole drilled in one end for the puller stud. 15 minutes and $2.50 at the hardware store. Works great!

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I also made a tool for the pressure washing the inside of the galleys to clean out blind holes. I got an extra Ryobi pressure washer coupling from Home Depot (about $3)….and used a brass compression fitting.
The aluminum tube was from a $3 air blow off kit from Harbor Freight, shaved down a little on the OD to fit the compression fitting. Drilled and tapped the other end for a 6mm screw and then drilled a .065” hole in the side of the tube so that the water blasts sideways. You need to shave off the corners of the screw to fit the galleys and make yours about 6”shorter than mine but it works very well.

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Cleaning and Deburring tools:

NOTE: DO NOT…use any of these tools on the case parting lines or bearing saddles. In some cases you can use a small amount of LOW SPEED, STAINLESS STEEL Dremel tool brushes…but aside from that use GREEN 3M scotch brite pads in a limited manner….ONLY.

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To go from this….

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To this….in 3 seconds……without removing any measureable metal

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It’s a dead fit to the cylinder bore. It took one in/out pass. If you are not handy with your drill…buy the green one which is lower abrasive. These are about $3-4.

They are too rough and fast to use on the outside of the case.

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These and your Dremel tool with variable speed….will be your hardest working tools. They remove very little metal.

You should use the STAINLESS STEEL brushes almost exclusively. They are marked by copper plated mandrels. I included the part #’s. The cup shaped brushed in the middle are the work horse. The small diameter brush on the right are critical for the nooks and crannies.

The carbon steel brushes last longer…and work a little harder so you have to be careful not to chew up the surface. BUT….carbon steel leaves pieces of itself behind that cause a reddish brown haze when they rust.

You can get rid of that rust….but we will get to that in the later section.

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A selection of cheap Harbor Freight brushes and bore brushes are about $6 total and work perfectly for this rough stage of cleaning and deburring. There is something to be said for high quality bore brushes from BRC (Brush Research Corporation)…but not for this.

Use the nylon bore brushes in the galleys…not the steel or brass brushes.

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This is a great tool for high speed outer scale, deburring and polishing. The oscillating tool. In this picture I have a wood cutting bit that I have ground the teeth off of and polished a little.

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You simply lay it on a flat sheet of 3M red or green (start with green first…red only needs to be used for heavy duty stuff). Move it around by pulling it with your other hand. Press the oscillating tool flat on the abrasive and it works it for you. You can also do this with sandpaper.
Pay attention. You can only work about 20 seconds at a time as it WILL wear through the abrasive cloth and contact the case.

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For nooks and crannies…slow the tool down, use the edge of the tool…but double up the 3M abrasive by folding it over.


Washing sequence:

1. Rinse each case half separate in the sink to get rid of as much abrasive dust as possible.

2. Fill the sink with the hottest water possible…but only hallway up the case. That’s is about 5 gallons

IMPORTANT NOTE: if you are on a septic tank system…do not use TSP or Phosphate detergents!

3. Mix up a triple strong batch of TSP (Trisodium Phosphate) and hot water. This is 1.5 cups to 2 gallons of water. Stir it with a metal spoon…wear gloves and goggles.

This chemical is MOST important. It is cheap…maybe $4 for a 5 lb. box at the hardware store in the paint department.

DO NOT…buy the phosphate free version of it. You want the phosphates. Phosphates…those things they got out of our laundry soap back in the 80’s (for good reason) are WETTING agents and surface tension breakers. They make detergents MUCH more efficient. This is one of the things that the jet washer does not do. Mix that up and pour it into the sink.
The tub I have is 19 gallons. With the case half inside it holds about 10 gallons. You just need it deep enough to fully submerge the case half and have about 3” of water over it.

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4. Go to WalMart or the dollar store. Look for the cheapest no name laundry detergent you can get. And….do not be offended…but what I was looking for has labeling only in Spanish. The Mexican market version of the Ariel brand detergent STILL has phosphates in it in many locations (even though P&G said in 2011 they would be phasing it out).

I know…because I checked it with UV light! I bought a 1 kilo bag of Ariel brand at Walmart for $2….I bought this…because it is strong…and cheap…and has a ton of phosphate in it. It has a Godawful scent. Mix up a gallon of hot water and put in about 1/2 lb….a lot. Stir until fully dissolved. Pour into tub.

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5. Use a standard parts cleaner brush to work over the entire engine case. Inside and out. The crap just runs off of it. You can use your nylon bore brushes on the bores.

Wearing your goggles and being careful….use your pressure washer under water. This absorbs most of the splash back.

Do not rinse…just put it aside and move to the next case half.

6. Drain the sink. Use the pressure washer and hose nozzle to rinse inside and out thoroughly with hot clean water.

7. Now…with ventilation and a respirator and safety glasses and gloves on thoroughly soak the case in Super Clean or similar. Do not use purple stuff.
You are looking for a cleaner with sodium hydroxide in it. Super clean has it. Use the parts cleaning brush, bore brushes and get quite a bit of cleaner down in the galleys. Work the corroded area hard. This will get rid of most…but not all of it.

DO NOT leave this unattended. Over time Sodium Hydroxide can eat aluminum.

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8. Now is the time to use the pressure washer and the long cleaning rod sprayer. You will be amazed as you work this through and twist it around…..what comes out.

Sorry these pictures are blurry. My camera was in a “chemical jacket” and I was having a hard time operating with wet slimy hands…but you can get the gist of how well the cleaning sprayer rod and galley brushes worked out

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This is hard to see but that grime on the sink bottom is pumping out of the main lifter oil galley

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This HUGE wad of what appears to be oil filter media blew out of the flywheel end of the 3/4 side lifter galley!

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In this crappy picture you can see the filth pumping out of the galley plug location between 3 and 4

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Absolute oil and detergent mud on the nylon bore brush from the main galley.

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The crap in the sink filter just from the blowing out the galleys stage after the general wash stage.

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Most of this is grit, oil filter media, some bug guts and grass nest stuff. The white flecks are from the sink pipe and not the engine and the blue flecks are from my screen printing work and were removed from the inside of the drain pipe by the TSP and detergent.

9. Rinse very thoroughly inside and out and through the galleys.

10. Fill the sink again, submerge and scrub as a rinse.

11. Blow dry with compressed air

NOTE: as these dry….if you used carbon steel brushes…you will see the goldish orange rust appearing on the surfaces. Do not worry.

12. This last phase will neutralize the sodium hydroxide and start to change the patina of the case and get rid of the rust blooms.

A. For the faint of heart or not having the surroundings or drain system to work in…You can treat the entire case with vinegar inside and out. You will need 2-3 gallons of strong white vinegar and you will have to soak it a bit.
B. For those with experience or are careful and can follow directions….a diluted (but stronger than vinegar) acid wash.

DO NOT do acid mixing anywhere near the engine case or aluminum parts.

You need:

1 quart muriatic acid
A clean 1 gallon plastic water jug
A 5 lb. box of baking soda (keep this away from the acid for now)
A respirator with magenta and yellow coded acid and organic vapor cartridges
Splash goggles…not safety glasses…goggles.
Nitrile gloves
An apron

A garden hose with a sprayer nozzle. Keep it on so you can rinse or spray things you accidentally splash
Good ventilation.
A clean, degreased scrap of aluminum.
A small glass measuring cup in ounces
Cotton swabs

Bonus: Cheap 10 step PH test strips from hardware store or pool store


To mix:

ALWAYS POUR ACID INTO WATER AND NOT WATER INTO ACID.

Put 2.5 quarts of clean water in the gallon jug. Pour in 3.0 ounces of acid. Swirl once to mix.
Add three ounces at a time until you reach 9 ounces.
Take a cotton swab and dip in in the acid.
Touch it to the test strip if you have one. It should read the strongest step now to be a usable acid solution which means a PH of 1.0 or 0. If it’s at 2.0 PH….add a little more acid.
The test strips only tell you that its a working solution level. It cannot tell you how strong it is concentrated.

Now…make a little spot on the scrap aluminum with the Q-top. If it fizzes fast and yellow…it’s too strong….add some water. At this stage you are looking for no immediate fizzing on the aluminum…but…within about 1 minute of careful observation you can see some faint white bubbling that will turn into a kind of foam on that spot in about 3-4 minutes. If it is faster than that…your acid mixture is too strong....add some water.

Mine took 15 ounces to 2.5 quarts because my acid is 3 years old and is weaker. A new quart of acid should take about 10-11 ounces. BUT…Home Depot and other stores have been selling half strength muriatic acid for about 3 years now so do not be alarmed if it takes you more.

Using the acid:

In an empty sink with the case half in it:

Rinse the case half to get it wet.
Pour some acid mixture into a plastic cup in the sink and work it quickly over the entire outside of the case paying attention to rust areas and corrosion areas. You may see some faint smoky vapor.

Do this for two minutes at a time ONLY.
Rinse it will on all sides and in the galleys. Repeat if necessary.

Flip the case to the inside and repeat. Rinse well in all areas. Spend five minutes rinsing. Do the other case half.

Fill up the sink with clean hot water pouring in about 1/2 cup of baking soda while filling the sink. Submerge each case half and soak for 2-3 minutes. Drain the sink and refill with clean water and pressure wash under water as a rinse.

Dry with compressed air and oil all studs and bolts with WD-40 or they will flash rust (will not hurt them)

This removes about 99% of the corrosion scale and all of the rust flashing from using carbon steel brushes.

Disposing of the acid mixture:

Fill up the sink with cold water about 3/4 full. Get a stirring stick. Pour the acid mixture into the water. Then add in 1 cup of baking soda at a time and stir. Even at this dilution it will fizz madly…and will start turning a light brownish orange. Add a cup of baking soda at a time until it stops fizzing all the way. Test it with a test strip. A PH of between 5.5 and upwards to 9.0 is safe to drain to the sewer.

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After the first stages of washing most of the corrosion in the “before” picture was still there and fighting it with a stainless steel bristle brush was not cutting it. After the acid wash only some small bits of white corrosion were still there. This scraped right out.


After washing inspection:

These are some shots of after the wash and an initial wipe down looking for missed spots to take note of to get cleaned up after I do the crank and cam assembly checks this week. These pictures do not do the case justice. It pretty shiny right now until it gets its normal aluminum patina again. The areas that look dark or dirty are actually clean and are just turned opposite the bright lighting

The 3/4 side of the case

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The 1/2 side of the case

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This is the main lifter galley on the 3/4 side. The light is coming through the lifter oiling slots. There is still some scale at the 90° bend at the end I will get with a brush on a rod on on the next washing and will do the same for the other main galleys.

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This could almost work into a separate thread just for case cleaning and de-burring and the tools and methods so I will start there. I just finished the first MAJOR cleaning after deburring….yesterday….to make it clean enough to put the crank and camshaft in for checking and fitting. I will have a couple more stages of washing after I surface and hone the lifter bores.

Type 4 engine galley plugs:

It used to be getting oil galley/gallery plugs was as simple as going down to any FLAPS and picking them off the rack. No so anymore. AutoZone and Advance were totally worthless….even when I gave them Dorman part #’s I looked up on line….they had zip.
O’Reillys did quite a bit better and had a range of plugs but mostly not what was needed. Incidentally…these are usually noted by modern FLAPS as oil pump plugs and are mostly used for full flow work etc.

NAPA…had it all! Gotta love these guys! These are some part numbers that work to get you standard recessed Allen wrench style, zinc plated steel galley plugs in three sizes.

Plug Part #’s from local Sources:

Dorman products (can be ordered from most FLAPS):
1/8 NPT: 090-046
1/4 NPT: 090-026
3/8 NPT: 090-019

NAPA part #’s:
1/8 NPT: 7041886
1/4 NPT: 7041875
3/8 NPT: 7041887

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These three plug sizes should cover everything.

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These are the plugs I took out. There should be 11 plugs total. Yes…I am missing one of the 11 plugs. I dropped it.


If you are doing one single engine and that’s it…just buy three taps. Use them to start the bores and then grind them down to get better taper. You may need to grind them down in two steps about 2.5 threads at a time. You can see the difference in the pictures.

Taps:

3/8-18 NPT
1/4-18 NPT
1/8-27 NPT

Two taps each: one for starting and one ground off to bottom the threads

Five 3/8” NPT
Five 1/4” NPT
One 1/8” NPT

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You may need to grind a few plugs to length. Do your first stage of tapping and then test fit a galley plug. Then grind a plug FIRST before doing the second tap stage. The second tapping stage reduces taper and grinding the plug increase taper. Check before grinding the taps and doing a second and third stage of tapping.


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Removing the cylinder studs:


Drip a little penetrating oil on the threads from the inside. Tap/vibrate them a little and let sit for 15 minutes. Double nut each one tightly. Then heat with a small flame for about 20-30 seconds. It only needs about 300-400 F. They turn right out. I numbered them as to location.

Next up:
I have most of these done just no time to post right now.
1. The dial bore gauge maps at 12 points of each main bearing bore
2. Crank journal measurements
3. Rod baseline roundness and width measurements
4. Pictures of checking main bearings tro crank in case
5. Pictures of fitting cam, getting double thrust cam bearings seated and mic’ing cam gear lash.
6. Waiting on a new 800 grit X 1" Flex hone to clean up the lifter bores in the next week.

Ray
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Lars S
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PostPosted: Sat Feb 03, 2018 4:36 am    Post subject: Re: A 1.8L 412 engine build thread Reply with quote

Thanks Ray!
Will as usual be wery intresting to follow your work! Very Happy
By the way I believe this is a 412 case, the 914 had the engine no stamped in another location.

Thanks again!

Lars S
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raygreenwood
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PostPosted: Sat Feb 03, 2018 10:38 am    Post subject: Re: A 1.8L 412 engine build thread Reply with quote

Lars S wrote:
Thanks Ray!
Will as usual be wery intresting to follow your work! Very Happy
By the way I believe this is a 412 case, the 914 had the engine no stamped in another location.

Thanks again!

Lars S


I must be getting old!.....you know I know that!.....and even worse......there is no way it could be from a 914....because it uses the lower dip stick tube! Its for a 412 wagon!

I got a little carried away trying to make the point that....thankfully.....there is really no way it came from a bus!

Thanks for correcting me!
Ray
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PostPosted: Sat Feb 03, 2018 9:58 pm    Post subject: Re: A 1.8L 412 engine build thread Reply with quote

raygreenwood wrote:


I must be getting old!.....you know I know that!.....and even worse......there is no way it could be from a 914....because it uses the lower dip stick tube! Its for a 412 wagon!

I got a little carried away trying to make the point that....thankfully.....there is really no way it came from a bus!

Thanks for correcting me!
Ray


Ray, no one can have 100% knowledge and memory about these cars...you probably only have 99.999999% Laughing

Lars S
_________________
Porsche 914 -72, Bahia Red daily driver Smile
VW411 2-d -70, White, sold Sad
VW412 4-d, -73, Gold Metallic, daily driver
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PostPosted: Sun Feb 04, 2018 1:26 pm    Post subject: Re: A 1.8L 412 engine build thread Reply with quote

2-4-2018

Important update:

Two items...one of which I forgot to get to in the original post:

1. OK...to a few who may have been cringing when I used a diluted acid wash on an engine case...realize that whenever you cast aluminum parts and whenever you have them anodized...they acid wash them.

They also may use various types of acid (or caustic) but always diluted to a specific range. Not to get into what is an "oxidizing" acid versus what is a "Non-oxidizing" acid here....because it depends on the concentration and the metal its going on.

I use muriatic/hydrochloric acid ...carefully diluted to below oxidizing level for aluminum....to specifically react with HEAVY corrosion and crusty build up that is sodium based (I think calcium and and a few other metals may also react). Time and temperature is everything as well. DO NOT heat up an acid solution...it multiplies its efficiency.

But...you will notice from the photos that the use of dilute muriatic acid still leaves polished surfaces bright....as compared to phosphoric acid...which is the most common acid used on aluminum...and is generally thought to be "non-oxidizing"....which is true.....but can be WRONG...depending on strength and dosage time. I will get to that in a minute.

2. Some probably noticed the polished smooth ...but mottled looking case...and may have assumed that I have no problem with that. I do...I'm just not worried about it! Wink ....because:

A. if I left it alone......within a few months it would be back to nearly uniform gray aluminum....and

B. As I noted...this is just the first stage of deburring and cleaning.

Which brings me to what I forgot to bring up.

After the first cleaning and acid wash....which was a very quick acid wash to get rid of corrosion so you cannot get it perfectly clean.....I was clean enough to see and feel burrs I missed and small pockets of corrosion in the corners and crevices. A little more Dremel and 3M green ScotchBrite work ensued and it went back to the sink for another round of hot water and Super Clean.

And....if you want to "normalize" the surface and get rid of any remaining light corrosion (or even heavy corrosion)....you use Phosphoric acid.

In this case....the engine case is still very smooth...very slight visual mottling here and there which if just different surfaces presented to the light at any time....but almost too highly polished....unnatural.

So the product I like to use is Jasco Metal Prep and Prime. BUT...it is a very high strength phosphoric acid mixture. Unless you are experienced with this...dilute it as per the directions.

Bear in mind the Phosphoric acid will not "eat" aluminum like muriatic acid....unless its very strong and you soak for a LONG time.....but it does etch and convert the surface at a microscopic level and creates an oxide.

The directions state to dilute it with 3 parts water and 1 part Jasco. This will give you 15-20 minutes working time for scrubbing in and working the product into all the crevices. If you are using phosphoric acid cleaner as the only acid cleaning/corrosion remover solution...you want a long time to work and scrub.

Since this is my second cleaning...I want a stronger solution and faster time.
Using this product undiluted will give you about 5-7 minutes before it started putting too much oxide on the surface.

So...Supper clean first...rinse well...and them Jasco MPP...working it fast and hard everywhere with the parts brush. Rinse well three times and blow dry with compressed air.

And this is the now stupidly clean case!

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This comparison shot is poor but its actually the same lighting. The shot on the left is after the first cleaning and muriatic acid wash. The one on the right is after phosphoric acid and secondcleaning.

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This pretty much the same patina the case would have after about 6 months in the elements.

Ray
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PostPosted: Sun Feb 04, 2018 2:41 pm    Post subject: Re: A 1.8L 412 engine build thread Reply with quote

Paint the block etc gray & accessories black so it stays looking like a professional rebuild for more than 6 months!

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PostPosted: Sun Feb 04, 2018 3:47 pm    Post subject: Re: A 1.8L 412 engine build thread Reply with quote

Mike Fisher wrote:
Paint the block etc gray & accessories black so it stays looking like a professional rebuild for more than 6 months!

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I never paint cases....ever.

And....unlike POS type 1 magnesium cases... Wink ....our ALUMINUM cases....stay looking the same for decades. They do not turn dark and greasy looking and grow white powdery funk.
Cool
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PostPosted: Wed Feb 14, 2018 5:58 pm    Post subject: Re: A 1.8L 412 engine build thread Reply with quote

UPDATE 2-14-2018

This is the cam deburring segment. The double thrust cam bearing is done as well. That part is a bit of a narrative....that I think may be useful to a lot of people who do not frequent the 411/412 forum much....so I am going to post that one in the bay bus forum and install q link to it in this thread.

Camshaft deburr and prep.

This is the Web #73. Over the years I must say I have never gotten a bad camshaft from Web Cam. Yes…a few people have found minor issues and had to get them straight…but overall their quality, packaging and appearance is superb.

Web does more than a fair job of deburring…or at least chamfering their camshafts. Not one to take chances in the valve and lifter department on type 4 (we have enough challenges as it is)…I carefully deburr everything.

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Yes…we are about to break some laws….in California!

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Contents of the box…a well packed and immobilized cam, the cam card and literature, Webcam Decals for your car and tool box and the lube and bolt kit.

I do not really like the lock washers that Web Cam uses. While they will lock the bolts…I find that the ID makes for a crude poorly aligned fit on the bolt. I will be using a combination of Loctite and Schnoor washers….or if I can find a better fitting version of the washer they use…I will use those and probably send the part # to Web cam.

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The Web # 73….contrary to the literature and some beliefs….is NOT a stock cam. It is used as an upgraded replacement cam for stock with D-jet and L-jet…because its lobe center is stock at 108° and its intake valve timing…..is close enough to the early V series camshaft code that 411’s used for both carbs and fuel injection…that its runs well with D-jet and L-jet. Its definitely a higher performance cam than stock.


The early V code stock cam had:

Inlet opens at 4° BTDC
Inlet closes: 39° ABDC
Exhaust opens: 40° BBDC
Exhaust closes: 3° ATDC

Several people have noted that the V cam was never officiwlly used on the fuel injected models….and was the carbureted early cam…but in reality it was used at least for the first year of US import for 1971.

Either way…even though the later “Z” code cams (used in the last of the 411’s in 1972 and all of the 412’s) had a little more duration than the later “V” code cams…. 11° more duration in the intake cycle….and 4° more in the exhaust cycle….. the web #73 compensates for this by using the early timing code AND higher lift. It is a stock “pattern” cam…optimized for slightly larger valve diameters which is good.
This is a great running cam in 411/412.

By the way….it appears that Web has changed the #73 very slightly. The current specs you can see in the cam card above….and the older #73’s were just a couple of degrees different.

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A few years back I made this nifty cam holder to make working on the cam easier. Yes…its cheap wood….but I keep it clean. Don’t let looks fool you.

I will probably remake this holder not far off and urethane coat it so I can wash it…but it makes no real difference. It’s just for deburring and then the camshaft gets carefully cleaned.
The white film where the journals roll is Teflon. Its etched Teflon film that has a backside that accepts adhesive so you can glue it down. It’s available here:
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Masking and materials:

I am primarily masking the cam lobes and journals so I do not accidentally damage anything if the Dremel tool slips.

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I use “Frog Tape” for delicate surfaces which is a very low tack adhesive. It’s a specialty painters tape. In a pinch you could use anything or use 3M blue painters tape…but this cuts a sharper edge and is much smoother and has less aggressive adhesive. Yes…its expensive…about $7 a roll at home depot….but worth it.

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My go to polishing wheel for many things is the Dremel #425 polishing wheel. Its medium hard rubber with 360-380 grit abrasive in it. The faster you run this wheel the smoother the polish (mirror finish on metals) but the more material it takes off….and the faster the wheel wears down.
It’s VERY soft and at anything over 15,000 rpm can wear down to a nub on hard sharp edged metal in minutes.

The cool thing is you can use the small dressing stone in the Dremel kit to put a knife edge on this wheel in about two seconds. I purposely keep small worn down nub wheels like 3/8” in diameter for getting into small narrow spaces. I used around 5,000 to 8,000 rpm to do this work.

I used a double overlap of tape so the outer edge is just about .020”-.030” inside of the chamfer.

What you are looking for and why we are deburring:

So these cams have a fairly nice chamfer on the edge. It’s also worth it to remember that Web Cam is one of the few that nitrides their cam lobes. This makes them HARD.

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The chamfer work and sacrificial black coating is almost always enough that one could take a cam out of the box and just run it with no risks….what…maybe 98-99% of the time?.....I do not want to be the 1-2% so a little extra insurance work is worthwhile to me.

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Here is what the chamfer looks like up close. In reality….they knocked off the hard corner…but just moved the hard “edge” over. While it greatly decreased the angle at which this hard edge is presented to the lifter face….which is good….we just want to radius or blend that hard edge….like this…which is better.

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NOTE: At first I thought that mark in the large circle was a scratch. It came out of the box that way. Under the magnifying glass…it turns out it was just a piece of dust or fiber of some kind that was on the lobe when they coated it…and….you can see the double mark from it. The shiny spot where it blocked the coating and the darker spit where it flaked off onto the still wet coating. Not an issue at all.

Deburring:

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These are the areas that need to be deburred

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Hold the Dremel steady with the polishing wheel at an angle to the edge of the cam lobe edge so it does not want to walk on you. Holding the edge parallel to the cam edge will burn a groove in the wheel edge. Holding it exactly perpendicular covers too little ground and causes walking off the edge quickly.

Even if the wheel does “walk” or slip off the edge you would have to remain on the tape for probably 10 seconds to burn through it.

Each one of these lobes took about 3-4 minutes at most. I made two passes. You need to have good light and keep a magnifying glass handy of your eyes suck like mine.

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I used a .035” thick feeler gauge with 2000 grit paper attached with 3M double sided tape to lap the thrust faces of the cam.

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This is the finished job. About 10 minutes to mask and maybe 15 minutes to deburr.

The cleaning of any parts on which I used abrasive of any kind….is hot water, detergent with a little bit of trisodium phosphate…then a very light acid/water rinse. In this case you could even use vinegar. I then rinsed it well and then dipped in in a bucket of filtered water (low mineral). Blow dry with compressed air and spray with WD-40 to drive away any moisture….then I am getting ready to do the double thrust cam bearing modification (actually its done…just have to upload pictures)
Ray
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PostPosted: Thu Feb 15, 2018 3:16 pm    Post subject: Re: A 1.8L 412 engine build thread Reply with quote

Double thrust cam bearing install on this engine:

https://www.thesamba.com/vw/forum/viewtopic.php?t=694420

I put it in the bay forum because those guys do not get out much into the "dark side" of true type 4-ism.... Laughing
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PostPosted: Thu Feb 15, 2018 8:10 pm    Post subject: Re: A 1.8L 412 engine build thread Reply with quote

You could get a really good job as a Technical Writer. Thx for all the info
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PostPosted: Thu Feb 15, 2018 11:55 pm    Post subject: Re: A 1.8L 412 engine build thread Reply with quote

chrisflstf wrote:
You could get a really good job as a Technical Writer. Thx for all the info


Laughing Laughing Laughing .......funny you should say that!........I actually do technical writing within my industry!
I wish is paid more!
Thank you! Ray
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PostPosted: Thu Feb 22, 2018 11:35 am    Post subject: Re: A 1.8L 412 engine build thread Reply with quote

Update for 2-22-2018

Basic connecting rod inspection:

This is just a short update. I did these basic rod measurements a few weeks back to see what we have before they go to the machine work.

Three sets of rods were provided:

Rod set #1: these were peculiar. Yes, they have been used…but VERY lightly and they are a little odd….at least compared to what I have previously found with 1.8L rods. Clean and pretty rods!

They have 1mm smaller ID’s on the piston pin bores. The stock pins are 24mm. These were undersized by almost exactly 1mm. So since they were “used”…they had to have been set up for a 23mm piston pin. I have no idea what for. A different application? Stationary/industrial engine? It’s not a big deal to fix them.

Rod set #2: These were a backup sent to me while contemplating what to do about the first 1.8L set. They are worth saving but they are a bit rusty and are 1.7L rods….but good enough to use if needed.

Rod set #3: these are pretty nice. They also seem to have been lightly used. They have a normal small amount of rust patches on the outside but are in nice shape.
The pin bushings are beautiful…pristine…almost hate to touch them they are so nice and round and clean…but they are oversized to the pins in the piston set by about .0001”-.0002”.

This is usually because the last set of pins that the rods were set up for were probably slightly toward the high end of tolerance by about .0001” to .0002”…and the bushings were honed accordingly. No big deal….it’s what rebuilding a rod is all about.

All rods “should” get rebuilt on any quality engine build. This includes “re-sizing” the big end to make sure it is round, facing the cheeks of the rod where it meets the crank, new pin bushings honed to size for the piston pins, checked for twist and straightened and balanced end for end.

The whole point of this short measuring exercise is simply to make sure that none of these rods are beyond use by being horribly out of round or mixed and matched with numbers or too narrow to be used with the crank.

First… it really helps to make a worksheet for this. You should log the stamped rod numbers on this sheet as you collect measurements.

A dial bore gauge is ideal for this but you can use a telescopic gauge and micrometer just as easily and accurately but it’s just a lot more tedious and time consuming…and you need GOOD telescopic gauges and it takes practice.

Also it’s ideal to have a small granite plate or a thick sheet of glass to work on at a minimum. Neither are required but it really helps. You can buy a 9” x 12” grade A granite plate for about $40 on Amazon…or a grade B (tool room grade accurate to .0001”) for about $30.

NOTE: these rods have just been carefully cleaned…hot water, Purple Power, some scrubbing with a stainless brush and wire wheel, dried with compressed air and oiled with WD-40. They have not been to the machine shop yet where they will be either bead blasted or shot-peened or both.

Assembling the rods:

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Make sure you match up the cap to the rod by number. Put a little oil on the threads and wipe off the excess.

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Mount each one in a vise between soft but sturdy surfaces and assemble them. I am using a block of aluminum on one side and a block of oak on the other.

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Work back and forth with the ratchet to keep the cap as level as possible as it mates up….until the nuts are seated finger tight.

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Then torque them to spec…24 ft. lbs.

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I place the rod on the granite plate and set up the dial bore gauge. I am not yet interested in an exact measurement with a micrometer. I take a few measurements between five axes to find where the largest and smallest diameter is and I mark the rod at these points on both sides with a Sharpie marker.

Then flip the rod over again and check these two points to make sure they are still the high and low points.

I do this because I am resting the dial bore gauge on the granite plate and rocking it to find the min/max measurement. This means the contact point is offset from the dead center of the bore.

It makes for very steady and quick measurements. That is the main reason for using the granite plate. It makes a very flat, uniform support base for the dial bore gauge. Checking these two points at a minimum on both sides of the rod will tell you if there is taper.

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Mark the rods in the five axes. The two axes on either side of the parting line are important because they tell you if the rod has spread or was machine poorly. You can move your axes anywhere you want or measure more axes but this is plenty for what we want now.

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NOTE: The Chinese dial bore gauge I am using in these pictures has my Starrett .0001” dial indicator gauge installed in it.
In reality…your real accuracy will be somewhat variable measuring the honed rod bore surface with a gauge this accurate because of the surface tooth that is on the rods from being honed….but it’s still a great indicator of the high and low points.

The allowed tolerance for connecting rod journal radial play is .0008” to .0027”. The out of round tolerance (which is mainly a measurement of the crank journal itself) is 0.0012”. The radial play is what is critical here. The out of round should be taken care of when the crank is ground. I just mention it for reference.

Although that radial play is the tolerance between crank journal and bearing….it’s even more critical for the rod itself. The rod bearing shells are thin. They conform to the rod and they warp as well at the parting line and they have bearing shell crush. If you have excessive out of round or tolerance in the rod itself it will telegraph to the bearing making oil tolerances variable .

So because the rod bearings when installed will NEVER be perfectly round…but egg shaped close to and above and below the rod cap parting line….you want the rod bore to be as round as possible.

That tolerance of .0008” to .0027” is a little generous on the high end. The oil tolerance between bearing and journal on the rods should be .001” per 1” of journal (rule of thumb)…MAXIMUM. You want the rod journals to be as tight and uniform as possible. They are farther down the oil feed line and have more squish....as compared to crank journal main bearings.

So with bearings installed…with a journal size of 2.163” you want an ideal oil gap of .00216”. A good rule of thumb is a maximum +/- tolerance of about -0.0002” on the minus side (do not go below about .0018”) and about + 0.0005”-0.0007” on the high side (do not go above 0.00266”-0.00286”).

So…all this measuring procedure is looking at right now is if we have anything REALLY out of round. Finding something 0.0005” out of round is not an issue. Finding something out of round by 0.001” or more…may indicate that the engine the rod was in died violently at moderate rpm…..and the rod bore is dented from the sudden stop.

This does not mean that the rod is unusable.….but it means it will take more work and require more to be ground off of the cap before re-honing the rod bore. And.... the more you have to machine out of the cap to resize the rod …the harder it is to get the exact length between big and small end correct and the harder it is to get the rod bore round.

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Check the width of the rod. These are pretty uniform. A quick measurement of the reground crank journal clearance says these should end up with about a total end float to the crank cheek of about 0.012” to 0.013”.

The factory tolerance is 0.004” to 0.016”. From that I consider 0.005” to about 0.015 kind of the limit of range. These will be just fine. With a clean up on the rod machine they will probably end up around 0.014”.

Even at the limit of 0.016” these would be fine. It’s not like you have much choice because it’s usually the crank that is worn a little. All that being near the limits on side tolerance means is that your pin bushings…AND the rod bearings and your crank end-play need to be as tight, correct and accurate as possible.
This will help keep the rod centered. If you let the pin bushing, crank end play and rod bearing ALL run sloppy to the upper end of their allowed tolerance, over time you can get a little more rapid wear to the pin bushings and rod bearings.

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It’s also a good idea to get a quick measurement between the bores. Yes…center to center can vary….and that is actually what is most important...and some of that is correctable during machining.

I will find out C to C measurements when I do a quick PlastiGauge check with the rod on the crank throw


But….it’s rare that there is a lot of difference in this particular measurement but once in a while you can find a rod from a different batch that is noticeably too long or short. Its nice to find that out now.

It’s these little things that can make a difference when setting deck heights. I would say that if you find a difference of more than about .005” with this quick and crude measurement….that rod should be swapped with another or needs some work.

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By the way….the micrometer I am using in the picture above is not really the correct tool for this ....because this model does not have a spherical anvil set….which causes the issue in the drawing above. The readings will be higher than with a spherical anvil micrometer or a caliper…but they will be consistently larger readings….and you will get the information you need just the same.

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This is my recorded measurement set. If you like this sheet just let me know. I can e-mail it to you. It’s just a word document.

Each item in the copy is in its own text box so you just click on it and type. I print it out and write everything on teh sheet and then transfer it to a live copy in the computer later.

I will post up the crank specs next and then these rods, the bearings and the bushings will go to the shop with the crank for rebuilding the rods.
Ray
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PostPosted: Thu Feb 22, 2018 11:51 am    Post subject: Re: A 1.8L 412 engine build thread Reply with quote

Just found this;
Love it!

Here I thought I was anal retentive..! Laughing
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PostPosted: Thu Feb 22, 2018 2:00 pm    Post subject: Re: A 1.8L 412 engine build thread Reply with quote

Clatter wrote:
Just found this;
Love it!

Here I thought I was anal retentive..! Laughing


I take that as a compliment! Laughing

Back in the day when parts were plentiful and cheap.....it was easy to be "less" anal retentive....and get away with it. Not anymore.

I try to do engines to the very best I can. Its more practical to do a little to much measuring...than not enough. Ray
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PostPosted: Thu Feb 22, 2018 3:07 pm    Post subject: Re: A 1.8L 412 engine build thread Reply with quote

raygreenwood wrote:
Update for 2-22-2018


Rod set #1: these were peculiar. Yes, they have been used…but VERY lightly and they are a little odd….at least compared to what I have previously found with 1.8L rods. Clean and pretty rods!

They have 1mm smaller ID’s on the piston pin bores. The stock pins are 24mm. These were undersized by almost exactly 1mm. So since they were “used”…they had to have been set up for a 23mm piston pin. I have no idea what for. A different application? Stationary/industrial engine? It’s not a big deal to fix them.


Ray


They are early 1700 rods. Used 69-70 and partially in the 1971 model year. Piston pins are 23 mm.
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PostPosted: Thu Feb 22, 2018 4:21 pm    Post subject: Re: A 1.8L 412 engine build thread Reply with quote

Pelle wrote:
raygreenwood wrote:
Update for 2-22-2018


Rod set #1: these were peculiar. Yes, they have been used…but VERY lightly and they are a little odd….at least compared to what I have previously found with 1.8L rods. Clean and pretty rods!

They have 1mm smaller ID’s on the piston pin bores. The stock pins are 24mm. These were undersized by almost exactly 1mm. So since they were “used”…they had to have been set up for a 23mm piston pin. I have no idea what for. A different application? Stationary/industrial engine? It’s not a big deal to fix them.


Ray


They are early 1700 rods. Used 69-70 and partially in the 1971 model year. Piston pins are 23 mm.


Thats really nice to know and interesting.....in that it refutes most of the common "texts" for identifying VW parts (Like hiw to rebuild your VW engines and others).

This is not surprising....as what is known of early 411 and 412 cars is poorly documented in North America.....because few if any were ever shipped here.

The odd thing is.....that these ARE what are listed as "1.8L" rods by all North American texts.

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These "odd" 23mm pin 1.8l rods.....are the one on top with the short balance pad. The one below is one of my 1973 1.7L rods.

And....

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It has the 022 prefix stamping that marks it "supposedly" as a 1.8L rod.

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Here is the 021 prefix stamping on my 1.7L rod.

Just like it does with anything relating to 411 and 412....it gets murkier.

Now that you mention the possibility that these are EARLY 1.7L....I am digging around in ky copy of the parts manual.
So....you have two connecting rod part numbers:
021 105 401
To: engine # Z 0 010 042
The prefix to the right lists "021". This means....according to this parts book....that its for carburetted engines.
However.....all 1.7L engines in North America except for a few early bus....are fuel injected and all generally had the 1.7L, tall balance pad rod with 021 stamped on it.

021 105 401 A
From: engine # Z 0 010 043
This one lists both 022 and 021 prefixes out to the right. The 022 is for fuel injected engines.

So.....I am guessing that the 022 rod.....what we know as a "1.8L" rod in use 1974 to 1976 on 412 and bus here....with 24mm pins.....were used on some of the early 1.7L.

Yes.....anything back in the "Z" engine code days...would indeed be "early" 411....and I have never seen a Z case in North America.

Many people have the idea that the 022 stamping denotes from a type 2. I have always known that cannot be true....because to many type 4 parts are 022....before there was a type 4 based type 2 vehicle.

Great information! Thank you!
Ray
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937carrera
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PostPosted: Sat Feb 24, 2018 5:55 pm    Post subject: Re: A 1.8L 412 engine build thread Reply with quote

I've been lurking around here for a few years, just making first posts, this is going to be a fascinating read, thanks Smile
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1974 412LS Variant 1.8 AN engine on twin carbs
1973 412LE 4 door Fastback / Saloon 1.7 EA engine on D-Jet
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PostPosted: Mon Apr 16, 2018 12:14 pm    Post subject: Re: A 1.8L 412 engine build thread Reply with quote

A “short” update:

Between weather and work (the garage has been in the teens and 20’s for too long)..…I am a little behind and even more behind on posting update details.

This will be a short update….meaning not everything thats done is being presented here. I have lots of crank and rod work pictures to post later this week.

But...short on photo content but long on reading/information....Sorry the reading here will be long on this one before the pictures….but I really hope it’s of interest. I am stoked at the technology behind this…and the cylinders got cleaned and prepped either way.

This is about the cylinder work….but only parts of it….but I thought some might find this interesting. Others…will say its overkill.

So as mentioned, this is a brand new NOS set of Kolbenschmidt pistons and cylinders. Because of their age…they have some rust. This is not about moisture….this is about the assembly grease/oil that is put on piston and cylinder kits back in the day which after about 20-30 years breaks down and absorbs moisture and rusts the cylinders.

So…the cylinders needed to be stripped of rust and oil, cleaned, painted and a light hone to put the proper surface back on the cylinder walls where the rust specks and streaks were stripped away.

So….the method to strip and clean is a process in itself:

NOTE: for those who are interested in all of the details of the EXTRA processes presented here..…I will make a separate thread about those processes so as not to clutter up this thread.

Cleaning steps:

1. Soak in sodium hydroxide. This will remove ALL oil, grease, paint etc. It will also remove any corrosion on parts that may be from touching a dissimilar metal….but will NOT remove most rust. Luckily the oil on the aluminum pistons prevented any corrosion to the pistons and any galvanic action between pistons and cylinders.

2. Soak in oxalic acid. This acid is one of the very common ingredients used in products like rust be gone and Ospho along with phosphoric acid.

You CAN remove rust with just phosphoric acid….but it WILL also convert the surface. That is great for the outside fins but is not great for bore as it take a very fine amount of metal away as it converts…meaning it takes the cross hatch down a bit. Not a problem since we are re-honing….but I just did not want to contend with the surface conversion for reasons I will get to.

You can also use muriatic acid which will take the rust off quick…but…it also gives you a little bit of hydrogen embrittlement…which will not hurt the cylinders….but causes very fast flash rust which also makes for hard working with painting and honing.

Oxalic acid has a different polarity. It removes rust almost as fast as muriatic acid…but does not cause rapid flash rusting. This is why it’s used in conjunction with phosphoric acid in rust removers.

You can buy it at hardware stores as a product called “wood bleach”. It’s granular and you mix it with hot water.

3. After the rust removal and a hot water rinse….the cylinders go into baking soda and water to neutralize. If you leave them wet to dry, the high PH prevents rusting. If you rinse them off well…they will slowly start to flash rust. The neutralizing gives some working time.

The extra steps below….are for the “EXTRA” things I have done... Very Happy

4. Short soak in trisodium phosphate. This is a surface wetting agent. When they leave this bath…the rinse water (distilled water dip)….should form a perfect film over the whole cylinder.

I am doing this step….because I am nickel plating the outside of the cylinders.

Why am I doing this…seemingly… crazy thing? Three reasons…with a lot of research behind them:

1. Because after lots of experience with VW cylinder castings…and talking to a LOT of metallurgy people over the years….one common issue with cast iron is that in thin castings like the fins…there are lots of mold and cooling stresses. These stresses cause micro cracks. Those cracks in themselves may never pop loose….but RUST…can and does exploit these fine cracks and fissures. This is one of the main causes of fins cracking off of even very well cared for cylinders.

I cannot tell you how many cylinder sets I have found over the years that are perfectly packed, no dings or dents on the box….and have that one top fin that just cracks off. To add to this….have you ever looked very closely at a lot of the top fins of brand new perfectly packed cylinders….and found one with that top fin that looks slightly bent?

I have a brand new NOS set like that in my stash. I will post pictures of it later. Cast iron does not generally “bend”. That off angle look is usually caused by one section of the mold cooling too rapidly or too slowly. It will have cracks/fissures.

In short….keeping the cylinders from rusting on the outside will keep some of these fissures from being exploited and causing an actual crack.

So a big chunk of this is about long term preservation of hard to find/special parts…for a special car.

2. From my own testing….and numerous technical articles and speaking to lots of metallurgy people across a spectrum of industries….bare metal cast iron…will actually shed heat at about a 3-5% higher rate than rusted cast iron.
The iron oxide is an insulator of sorts..…but at a more complex level than just being a coating….it’s an insulator at an electrolytic level.

So keeping the cylinders from rusting is a good thing for cooling too. A small good thing….but a good thing nonetheless.

So…why not just paint them? Of at worst/best…..why not zinc plate them? Why nickel?

IMPORTANT NOTE: To understand the answer to that last question...one must bear in mind….that heat travels through metal by conduction….and that conduction is caused by “free electron” movement.

Meaning as metal atoms heat up they start to shed electrons during expansion….which travel from shell to shell in the atoms…moving toward cooler metal. Heat always travels through metal from hot to cold. So the fins MUST be kept at a lower temperature than the cylinder body if you want to keep pulling heat out of the cylinder. Heat shedding is about physics.

This physics fact….is important to keep in mind while I explain why I am using nickel and not just paint or zinc. Keep the physics in mind and I will get back to it.

3. Black paint itself is a good thing for heat shedding. There are some really EXCELLENT heat shedding, flat black paints out there that can increase heat shedding by as much as double…no kidding.

There are two paints I have used in other industries….but they are just too expensive to justify. One is a 800° ultra, flat black paint (comes in a 1200° version too)…but is $130 a gallon.

The other…which is even more flat black….probably the flattest black paint in the world…but just barely in the right temperature range at about 450-500°F….is about $330 a gallon.

Why such a big deal about being super flat black? Because it’s about the emissivity coefficient of the surface. The flat black being super high emissivity means that it not only can absorb heat transmitted by light…photons….but can shed it quicker by electron transfer to the atoms in the surrounding air.

Of those two super black paints….the cheaper higher temperature one is primarily designed to pull heat out of metal and shed it….and the flatness of its surface is just part of that mechanism.
The other more expensive paint…is primarily used in optical tube work in satellites and aerospace…both to shed heat and also to be TOTALLY non-reflective. Its prime use is to absorb and then radiate away absorbed visible and infrared light without disturbing the optical instrument it’s on.

So why not zinc plating?…its better at preventing rust. BUT…it’s also not good with high heat applications. Its crystalline structure breaks down over time especially with heavy expansion and contraction….and as it forms its sacrificial white rust…it will eventually flake off the paint.

So why nickel?....and here we go! Laughing

Remember that part about electrons traveling through metal from shell to shell in the atoms?
This process is HEAVILY studied in many industries. I had seen this usage of nickel plating and black coatings when I worked in the solar industry….and did not at the time understand the what and the why. Many articles, papers, conversations and years later….I finally get it.

In the solar industry, some aerospace applications etc…..with applications where absorbed heat MUST be kept to a minimum for electronics….they nickel plate the outer surface of the metal…and then apply a “black body” high emissivity paint/coating.

For example, many solar collector grid frames…the frames that hold the solar panels…are done this way because absorbed heat causes an efficiency drop of several percent on thick film silicon wafer cells.

The nickel….forms a very high electrolytic bond to the surface….and creates a MUCH more direct transfer to the outer surface of those traveling/conducting heat electrons.

Research into this has found that just leaving bare nickel or a polished outer surface…while reflecting away a lot of spectral heat and infrared…is actually a low emissivity surface. Its surface and thickness has very low mass for absorption. It’s good for transfer of electrons…but not for absorption of them. That’s what the flat black coating does.

It has been found that an improvement of an honest 35%-40% to heat shedding can be achieved by this method...but the nickel plating must be done with "electroless nickel"...not regular nickel electroplating...to get heat shedding efficiencies that high.

I will be doing standard nickel electroplating here...because "electroless"....is just too expensive for this much surface area. Electroless has more complete and even coverage than electro plate. But...the benefits are said to work at some level with both methods.

The black coating itself does not actually need to be that special. It must have no other metals like chrome, iron or lead in it…..and mainly must have an emissivity index of about 0.92 to 0.94. There are quite a few basic cheap high temp paints…that actually fit this bill. the paint I used for this is actually about $4 a can. Actually flat white has a better coefficient of reduced surface emissivity...but cannot work with the nickel because it typically has metals in it like Titanium and calcium that stop the electron flow from the inside.

So..to see if the paint plus nickel combo actually worked....I did some testing about 3 weeks ago on bare nickel ingot with several black coatings using my thermos anemometer, a dedicated airflow source, my Extech wet bulb thermohygrometer and a good thermocouple.

I measured bare nickel after heating to a specific over temp point and letting it cool down to an exact # before turning on a exact temperature and volume cooling air flow and measured cooling drop times.

I checked three paint coatings with high emissivity and two thicknesses (8-12 micron and 23-25 micron) of each…three tests for each coating…18 tests total…..and damn….I found a CONSISTENT 13% decrease in cool down time….compared to bare metal…on one coating at 23-25 micron thickness.

If you consider that cylinder temps are generally on the 400° nominal to 500° range peak….that’s 52° at 400 to 65° at 500.

Because the heat source is constant…the cylinders are still going to get to their normal temperature….but they will shed heat faster. In hot weather/climates and long highway drives….this can make all the difference in the world.

So I nickel plated them to keep rust down, to make a better bases for the outer paint…and hopefully possibly have better heat shedding characteristics…and because I could.

The upcoming dedicated thread will show my ingot testing, the plating and cleaning method and…I have my old “mule” cylinder…a 90mm factory stock Mahle from 1972….that will be functionally tested in the test rig I built a while back. It will start out with its normal rust, heated and tested in dedicated cooling air, then stripped and re-tested as bare metal, then plated and tested with bare nickel plate and finally tested with nickel plate and black paint. It may be June before that is done.

So….the pictures of these cylinders. They get honed this week….

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The light flash rust is from the acid content of the plating solution. It gets removed before painting…about 10 minutes in cleaning vinegar is enough, then a distilled water rinse, dry at 150 for 10 minutes (oven or blow dryer)…then paint.

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Sorry these pictures of the painted cylinders do not do them justice at all. They are hard to photograph. Even though this is not being done for looks at all….they really do look sharp! So sad they get covered by sheet metal! Laughing

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After painting and drying, I mask them for lapping the sealing surface. I only did this on this one cylinder. Since the paint is not fully cured until its baked….I did not want to get oil on it yet.

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This is my lapping plate. It’s a spare piece of ultra flat “1/2 wave” glass I had left over from a tack level tester we scrapped in a lab I worked in.

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On the glass

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The resulting finish. This picture actually shows what the paint looks like.

More to come.
Ray
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PostPosted: Fri Apr 27, 2018 11:40 am    Post subject: Re: A 1.8L 412 engine build thread Reply with quote

4-27-2018 Update:

A bit of an update…or really a continuation of the last update.

Piston, ring gaps and cylinders.

I have been waiting for new 90mm and 93mm torque plates but my local machinist buddy has been up to his neck. A lot of that going around….so I dug out my old torque plates.
These are made from a stack of four ¼” Mic-6 aluminum jig plates. Two are 93mm and two are 90mm so I can work those two sizes. They take a little to line up but once torqued down they work just fine.

The base plate to lock in the vise is a stack of two ½” thick Mi6-6 aluminum plates.

So first things out of the way:
So why am I having to hone these brand new cylinders? You could see a little of the rust in the last pictures before I plated the outside. These were old NOS. They had some patchy rust mostly from the sheer age of the grease that was originally in them the way they were packed.

Many…would have just sanded lightly and run them….and I say…no, no, no!

Patchy rust means the cross hatching in those areas is literally GONE. A rust patch can also wipe the edge right off a ring.

So…since most of the factory hone cross hatch was still in good shape….the first order of business was to get a reading on that cross hatch so I could duplicate it as closely as possible in both angle and surface profile. I am the first one to say that in general the piston company’s probably have a good idea of what works.

The next step was to get one of each ring from each piston into the bore to get a handle on what the ring gaps are like, whether they need grinding (rare on complete factory piston sets)….but mostly so I would know how far I can hone them and still stay in comfortable spec.

The first item up is that I am using a flex hone for this.

Why?

Because when you are honing JUST to get proper hatch and profile……and are not honing to oversize….its damn hard to have a shop set these up on a honing machine and just reset the surface profile…and not oversize them. I have had too many cylinders sets (three really) ruined this way by well-meaning shops with fabulous equipment.

They come back beautiful in surface and hatch angle…but are several thousandths oversize. Junk.

The dedicated hone machines usually have higher stone tension than they need for just a quick profile. Yes…it can be adjusted but rarely is by high volume shops.
So they cut too fast. On a Sunnen hone you would literally have to do about 3-5 strokes and pull the stones out, clean and measure...and repeat. And no…you cannot just go to a smaller grit stone so it cuts slower…because the stone grit sets the surface profile.

I have just recently argued with others here in the forums about the proper use of flex hones.
When used for exact specific things and with care and planning.…they work superbly…AND only really for this ONE task….surface profiling and cross hatch.
If you are straightening a tapered cylinder, a deeply scored cylinder or honing oversized…you MUST put your cylinders on a REAL honing machine like a Sunnen hone machine.

I have found that people getting poor results on this ONE task…with a Flex Hone…comes from using poor technique with no pre-set up work or measurements. It’s a tool like any other.

These two pictures show the general rust patch disposition of all four cylinders. This is before I lapped the seats or plated the outside.

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So the first thing to do was get out my most important cylinder….my 90mm trophy cylinder from a blown 412 engine. Laughing

This is an original 1.7L 90mm cylinder from 1972. This is my mule cylinder I use for all sorts of testing…and for practicing with a flex hone to get proper stroke rate, speed and hatch angle.
It’s actually quite valuable to me as a tool. It’s a pristine cylinder that is would be still functional if I needed it to be. It is the “mule” for a range of testing I am doing. Lucky I kept it!

So here is the factory cross hatch angle picture from one of the NEW NOS 93mm cylinders
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I found the hatch angle varies quite a bit actually…from a little less than 40° up to about 53°. These are actually 48° on this cylinder. They also vary some from spot to spot because of the stones in the hone machine changing direction while in motion. But they are fairly consistent.

So do not let anyone tell you how precise the hatch angle needs to be…or that they can make a perfectly consistent hatch angle in any given cylinder. It’s physically impossible. It will have variation....even with a factory or Sunnen hone machine.

After doing some test hones on the 90mm mule….I got to this fairly readily with a stroke rate of about 80-90 strokes per minute and full speed on the drill (1720 rpm) with sae-10Wt non detergent oil.

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It looks a little rough because this was a rusted cylinder in some spots. It also illustrates what rust can do to the base surface profile.

After superimposing lines along with the factory hone pattern…this is the comparison:

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The yellow lines are factory and the red lines are the flex hone. This shows that I need to increase my stroke rate.

NOTE: the Flexhone instructions are pretty spot on.

They list a stroke rate of 80-120 SPM…just to create an evenly honed surface. Then you increase stroke rate higher…yes…that’s hauling balls fast…just to set the cross hatch. I ended up at about 130 SPM for a 40°-50° cross hatch range. I will have pictures later.

So how do I know my strokes per minute?.....download a free metronome file for your phone and slap on the headphones when you practice and work.

https://play.google.com/store/apps/details?id=com.andymstone.metronome&hl=en

I used this one. Dirt simple. But….delete/uninstall it when you are done. It’s a data mining app like most other free apps.

So here is the torque plate set up with the 90mm mule in it.

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Yes…the bore has blue dye on it so I can adjust my hone rate and see how many strokes are required for an even finish. It’s the only one I needed to do this way.

I started with a 240 grit Flexhone running clockwise. Then finished with a 320 grit flexhone running counterclockwise for a plateau finish. A grand total of about 20 seconds on the 240 at 90 SPM…so right at 30 strokes.

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This is 240 surface. It looks rough in this light and angle but is actually quite nice.

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This is after 10 seconds with the 320 grit.

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After a quick clean I read the surface profile. Too smooth.
And the hatch angle was too narrow as you can see from the previous photograph…but the plateau section of the readings were spot on so that part was right I just honed too long on the 320.

So…I gave it 10 more seconds with the 240 grit at a faster stroke rate….almost dead on factory.

So…here are the surface profile readings from this practice session.

The original factory surface profile readings in green were taken from the below the piston skirt area of the cylinder that the piston never ran on and had no rust.
By the way…I will explain these measurements fully at a later point probably in a different thread…but each of these surface profile parameters means something specific. You are mainly looking for a constant trend…as the readings can vary a lot within any given cylinder…and not to be too worried if the number difference looks a little large. These are in “micro inches”.

There are 39.37 micro inches to 1 micron. There are 25.4 microns to 0.001”….so there are 999.998 micro inches to 1 inch. A variation of say 60 micro inches in one reading or another out of several spots in the cylinder may not be significant. However more than say two of them are 100 micro inches or more off…and consistently off….that says something.

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So what the readings mean…and I am simplifying greatly here….The Ra and Rz are about average roughness of the absolute peak profile height or the sharps tips of the scratches over the length of the sample.
One is a mathematical average of every peak/valley that was read (Ra) and the other is an average of the peak/valley reading with deference to the total sample length (Rz)…a ratio if you will. The Rv is the distance between the deepest valley and the mean or median line of the profile graph and the Rp is the same but to the highest peak. The Rt is the total distance between those last two measurements from peak to valley.

What those last three measurements really speak of…is the width of the valleys created by the abrasive…and the resulting valley wall slope.

You can look it up here for some basics.

http://www.predev.com/pdffiles/surface_roughness_terminology_and_parameters.pdf

Among all of these numbers they describe a microscopic cross section of the surface roughness and spacing of the scratches.

So now I had a decent honing recipe/formula…and got to work.

All the cylinders got a clockwise 240 grit, 90 SPM initial plunge rate honing, then a 320 grit honing for half the time in reverse at 90 SPM and then a final 240 grit honing for half the time at about 135 SPM. All told it was right at 40 seconds of total honing for each cylinder.

It does not take long. This is why its a bitch on a hone machine to set this up and not over do it.

It was too sloppy of work to get real pictures of the honing process. But here are the average profiles after I got done.

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Where in the cylinder I am reading the profiles:

I read them at top, center and bottom and at two sides around the bore. Six readings each. I throw out the largest and smallest wide variations (usually caused by the point where the hone stroke changes directions) and average them. It’s not the ideal surface profile gauge for this work….as its tricky to get it set up with all four feet on an internal curve…but it’s pretty accurate. It works better on external curves like measuring a shaft.

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Not bad at all….so far. I will “drag” test each piston and a middle ring later and see if they need a touch up.

Here are the ring gaps out of the box for all rings. Not perfect but well in spec and very normal for cylinder sets that most mechanics and rebuilders just clean (hopefully), set ring gap spacing and slam them in.

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After honing…they grew a little bit but are still well within spec. I kept the ring sets separate as they came from each piston. I figure the piston company was not stupid and did some measuring and tolerance sorting.

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Don’t be alarmed by the larger growth of some cylinders compared to others. This reflects that I had to hone two of the cylinders more because they were rustier and I honed. Stopped, cleaned, measured profile and looked at hatch angle and rust areas.

But I will mix and match rings to get the best fit.

BIG WARNING!
And this is something I always check. But getting a little out of sequence…I am glad I checked the ring gaps before I did the final honing.

They were RAZOR sharp on the edges. You should ALWAYS check and deburr the ring gaps.

This is the mark this one left. It’s mostly just black oxide but it pissed me off.
Evil or Very Mad
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Here is the edge of that ring (and pretty much all of them) under the scope…..razor sharp!

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And after deburring. This took under 15 seconds per ring with a diamond needle file. You have four flats to make one swipe across at a 45° angle and four corners on each face of the ring.

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Then put a ring in the bore carefully.
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Then square it up with the piston
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Then measure the gap with feeler gauges
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After I look around at the final numbers I may mix and match ring sets to get more even ring gaps. If all else fails I will file a ring or two to get all ring to cylinder gaps the same on each cylinder.

As I noted I will be doing a “drag” test on each piston with one or all rings in its cylinder with a simple digital pull gauge. This is really to tell me if the ring gaps combined with piston and cylinder honing are fairly equal. If one is way off I may do a very light hone to that cylinder. My good pull gauge is out on loan to a customer….so it’s the digital fish scale!...and it’s not half bad for $18

Part what goes into this mix and match is not JUST for drag and size….but ring gap comes first. The weight of each part is also being taken into account for mixing and matching for best balance weight.

I will try to get the rings with the best existing ring gaps into each bore. Then I will set the smallest and middle equal to the largest as long as they are still dead in the middle of correct specification.

Then using the rest of the components….snap rings, piston pins and pistons….I will mix and match for weights. If I have a ring of the same gap size that is slightly different enough in weight to make a difference…I will swap that around if needed.
But with what I have I think I have enough small gram differences to get damn close without swapping rings for weight reasons.

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Here are my component weights.

So other things are coming. Lots of pictures of crank and rods. Oil pump rebuild work is this weekend. Pictures coming soon!
Ray
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PostPosted: Sun Apr 29, 2018 5:46 pm    Post subject: Re: A 1.8L 412 engine build thread Reply with quote

Update for 4-29-2018

I will post the basic oil pump pictures here in the build thread….but since this has merit to enough people that may not look at the build thread…I will also make a separate thread for oil pump rebuild later and link to it in the build thread.

I will add to the separate oil pump thread as I get into rebuilding other pumps that need more work than this one.

As type 4 pumps go…..this one is in excellent shape as far as the main case goes. One of the best I have seen in years. The gears have a little wear but are not outside of tolerance. I would call them at about 75%.

If this pump is used in an engine with good oil filters and air cleaners and on time oil changes and an in tune engine….it should last another 125-150k miles after it gets tightened up a bit.

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Note the 2 scratches. I think from what the owner told me that this engine died semi-violently. These two marks come from a couple of pieces of grit/metal being laying right in the port when the pump was pulled. No problem at all….just something I have seen before.

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Moderate but common wear to the drive tang. Nothing to worry about yet. I will check the fit in the cam.
The idler shaft position is normal depth.

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I opened this just in time. The oil had a very slight rusty tinge from absorbing moisture over the years.

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The area in the circle is very faint/thin surface rust. Not an issue but if I had waited say another year to open this pump or clean it out it may have been toast.

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This is the driven gear side. VERY clean and smooth pump cavity walls. Not a lot of grit or metal went through this pump. GREAT pump core!

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The idler gear side looked just as good.

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The pump plate had standard smooth wear rings. No big deal. I can lap that out.

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You can see the gear edge is VERY smooth. Little or no grooving from pumping crap through the pump.

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The plate side of the gear

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The pump bidy side of the gear

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It looks like the pump was surfaced slightly to put clearance into it.

OK…now for the measuring. A couple of important items when measuring gear backlash:

1. Check several gear teeth. It can make a difference. If the surface of one tooth had a little rust or is rougher…it can make a difference of about .0005” easily. If that goes into your decision not to use a pump or gear….it may only be that one tooth or the location on that tooth if you are close to the limit.

2. You do not need a jig as elaborate as mine...but you should make something:…I mainly made it to practice my welding a few years back….but take a little time to make sure that the plate is supported and that the driven gear is rock solid locked so it cannot move.

NOTE: Do not say this is overkill. Or costs too much to go through this much stuff on a type 4 oil pump.

If you are rebuilding or refurbishing a stock type 4 pump…you are NOT doing it to save money, time or effort. If money, time and effort are critical to you….then you should be buying a CB Performance 26mm standard pump and doing the work needed to make it fit properly and work on the relief valve to make sure that your pressures are right or buying a Schadek pump and going through what it needs to fit the case (like an o-ring mod).

The only reasons to work hard on a type 4 pump is because it fits very well, gives proper relief valve operation without tinkering…is an elegant pump design (no pesky outside plate leakage or finding odd gaskets thicknesses)…and you are keeping it simply for originality, preservation and restoration purposes.

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So here is the pump late locked to a small jig and the drive tang is locked tight and the dial gauge 0’d.

And……

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This is the WRONG WAY to push/move the gear…pushing from one side.
Note that the dial gauge says this gear set lash is basically worn out….at the extreme of its tolerance at 0.008” of lash. And that reading is incorrect. Note the yellow arrow I drew across the gear.

What happens is that the shaft diameter is 0.550”. The gear bore is 0.552”. It has 0.002” of tolerance. Just pushing at the top edge of the gear causes the gear to TILT against the shaft…giving you quite a bit of skewed tolerance.
When the gear set is full of oil it has pressure all the way across the gear and loads it evenly with no tilt. If it did…you would see a slanted wear pattern in both the plate and body.

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When you load the gear evenly in the center…..not the yellow arrows on my fingers and note that the reading changes to a dead stable 0.0064”….much better. Its at about 75% of its wear but still just fine.

You get this same mistake when using just a feeler gauge jammed in between gears from the top. It wedges the gear against the shaft at a slant giving you a higher level of wear reading.

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The dial depth gauge is 0’d on the inner deck.

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Now its on the gear showing 0.004” of depth difference. It is said…at least in type 1 pump building that 0.004” is the maximum tolerance. I think its way big. I will lap it down in the next episode.

NOTE: With regard to gear to plate clearance...I agree with the Wilson book (How to Rebuild Your Volkswagen Engine)…really… the gear to plate tolerance should be close to “0”. Not dead 0.000” like he notes…but just close enough to 0 to allow clean smooth movement at freezing temps. The pump expands as it heats up.

You will get about .0015” to .002” from a dry room temp tolerance of about 0.0005”. It just needs enough clearance to force an oil film under it.

My funky back lash measuring plate:


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Its made out of a piece of 2” wide X 0.125” thick mild steel strip and a couple of pieces of 1” side x 0.125” thick strip…a little grinding and drilling, some tack welding practice and cheap black paint. I spent about 3 hours on it a few years back. Partly because I wanted to go through a handful oil pumps…and I found the issue with reading lash accurately…and also…it was an excuse to play with the mig welder I just bought at that time….and you can see I needed the practice.

More to come !
Ray
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