1.7L EA assessment

[Danno5]

I am at the point in going through my car where I can look into what I can reuse vs. buy for my '73 412's engine. I am a type 4 novice so I really need some help from you guys on the forum determining what she needs. You guys name it and I can take a picture and/or measure it. My goal is to get stock power and be reliable enough for a weekly drive (after the front-end rebuild of course).

Here she is stripped of cooling tin:

Engine background: The car's odometer listed 29k miles, which has likely flipped a few times. It was running well immediately before coming out although it smoked a little bit and might have been a little down on power. It also made a popping sound, but I think it may have been an exhaust leak. I did a compression test and all cylinders were fairly even and around 110 PSI.

What it is: The block is coded EA and the heads are coded 021 101 371Q with breather tubes on both heads and a cylinder head temp sensor on the left head. The left head's part number was all blurry for some reason, but the right one was really sharp. This all appears to be correct for my 412 as far as I know (Wilson air-cooled engine rebuilding book).

What appears to be wrong with it now that I have the engine off: It's really filthy and I think nearly every seal leaks. Here is the front main seal as an example:

Next step past here? Thanks!

Dan

[raygreenwood]

Sorry...I meant to get to this earlier. Traveling for work

So.....with an EA series....depending on whether you believe all of the manuals.....it "should" have domed high compression pistons. Its stated compression pressure is 128 to 156 psi. Be sure you are testing warmed up, all spark plugs removed and the throttle blocked open.

Of all of that was done....then 110 is a little low....but being almost dead on for all 4 means its in great shape and just normal wear.

Alternately....I have seen more than a few EA series with dished lower compression pistons. They list a compression pressure of 100 to 135 psi. So 110 compression all around would put a dished piston engine at quite fair condition.

It could also be....at this age....and is most likely part of it....that all four head gaskets are leaking. They all leak. And if you remove them before they get a burn through....you just saved your heads.

The high compression 1.7L was absolutely the best snd longest lasting all around type 4 engine. The 1.8L is just as good....when its built with higher compression. This can be seen in the European twin carb 1.8 at about 86 hp. The domed piston 1.7 put out 82 hp.

So the easiest course of action is to do a good "refurbishment". It depends on you budget, tools and skills.....if it were me.....I would have the heads rebuilt with new seats and valves. Its just too old to trust original seats and valves.

The "Q" heads are the best. The 411, 412 and 914....well cared for ...were also the easiest on their heads.

You can go to one of the type 4 specific shops to just do heads....like Headflow masters or Mofoco.....or any decent head machine shop......but SPECIFY exactly what you want and be prepared to measure and check before you walk away. Buy the valves for them unless they advertize the same brand and part # you suggest. Go by the angles in the book.....and tell them new seats....blended on the inside.....with .006" interference fit.....and no flycutting unless you have a burned cylinder seat.

Buy your valves from Pelican parts or Automobile Atlanta....or Ac.net. Check the brand and size. Right now Pelican has TRW or Porsche. Good valves all around...in the right,sizes.

Camshaft......buy a new one. Do not risk the old one and lifters. You can get a web #73....which is a warmed up early 411 grind... or the 9590 from the type 4 store.....which is the same cam as the Web #73 with a little more overlap to run cooler.

Best money spent.....will be a complete camshaft KIT from the type 4 store. Cam, gear, lifyers, springs, retainers, Porsche swivel feet. Optionally with new studs and rocker shafts.

So before you disassemble....check the crank free play. If you get lucky.....when you CAREFULLY strip it down....you will most likely dind domed pistons. Check their skirts with a micrometer. They will probably,still be good. Measure ring grooves. Buy a good set of rimgs drom AC.net and a gasket kit. Set ring gaps...clean up....but a flexhone of about,240 grit and give the cylinders about 10 strokes. If they measure ok....and have no gouges or rust....you should be fine.

Also...you may find the main bearings ro be in good shape. If so.....clean yhem and reuse them. If not....its only about,another $65. We can talk then. We can tell you how to go through the oil pump.

Gist is....with these parts...you csn recurb to get another 70k excellent miles in the $2500 range or less. Ray

[Danno5]

Thanks Ray!

I will get on end-play before disassembly. As I understand it from the clymer I just have to get out the front seal (under the flex plate), reinstall the flex plate without the seal, and then rock it back and forth with a dial indicator attached to the case.

I took one head off yesterday to take it down to the local shop specializing in heads to get a quote. They quoted a good price but said they couldn't handle any oversize valve guides. From looking at AC.net it looks like I really should borrow a valve spring compressor, get in and measure anyway. Quite the range of sizes in guides available! I suppose that way I could at least test out all of the valves, springs, and guides to see what condition they are in.

By the way, these are the top of my pistons. domed pistons?

The head also had those head gaskets you were talking about by the way.

[Danno5]

Took the engine off the stand to get the best measurement of endplay. I think I am right in the acceptable range, but it was my first time using a dial indicator. Is my technique OK? I was following the clymer manual's instructions for this.

- First, took off the front oil seal. This tore to shreds pretty easily.
- Second, took out one of the three shims. I measured that third shim with a set of mitutoyo calipers and it was 0.0135 inches.
- Third, bolted the flex plate back on and tightened it up.
- Fourth, mounted the base for the dial indicator, harbor freight version, to the C-ring engine mount adaptor, got it from pelicanparts.com. It was either mouth on this or mount on the flex plate. The flex plate didn't give the most secure mount. The engine mount adapter is firmly bolted to the case in several places so I used it.
- Finally I pulled and pushed on the fan mount on the back of the engine with a pair of screw drivers and a few taps from a mallet. After a few tweaks I started getting consistent measurements around .017 - .018 inches. Subtracting that third shim measurement gave me about .004 inches which is right in the middle of acceptable end play: .0028-.0051" (Clymer, p. 40).

[raygreenwood]

Important thing!.....go get your heads back!....NOW!

Whatever shop you took your heads to....there should not be a single thing they CANNOT do to your heads....or they are NOT qualified to be working on them at all.

Air cooled engine heads in general ....but type 4 heads VERY SPECIFICALLY.....cannot be properly done by a generic automotive shop UNLESS they have a LOT of experience ......WITH TYPE 4 HEADS. Type 1 experience helps but is not enough.

Experience with water cooled heads does not count. Useful....many things are similar....but not the same.

A couple of questions.....typically unless you special order.....most replacement valve guides for type 4 are the first oversize.

1. If this shop says they cannot install them.....then it appears they have no basic machine work capability. They are just planning .....I assume from that statement ....to press in stock original size guides....which would be risky for them to stay in at this many miles.....or to just "knurl" the ID of your guides and re-use them.....which SHOULD NOT BE DONE.

2. With normal guide wear.....you cannot put new seats and valves in with any reliability ...witjout replacing the guides.....with NEW GUIDES. New guides need to be first oversized to be sure they will not pull out of the head or start moving the first hot day.

New guides need to be used.....because the ID needs to be reamed to fit the new valve stems.....to make sure that the radial tolerances are tight....because the valve guide is what the valve seat grinder stone pilot is installed in. It guides the valve grinding.

3. And.....the heads must have new seats at this many miles. They require a .006" interference fit......and you need at this point in time....new springs.

Do not skimp on the heads....and do not take them to anyone who does not have type 4 head experience....UNLESS they are an extremely skilled machine shop that can take explicit direction/instruction....and you are prepared to provide that instruction....and it will not fome from the clymer manual. Ray

[Danno5]

Crisis averted. Heads never went anywhere.

I also e-mailed the two places you recommended Ray, HeadFlow Masters and MOFOCO, for quotes and what they typically do with their rebuilds. Both came back pretty quick with some numbers and great information. Either way I will have to start saving up now!

I will probably box up the rest of the project until the heads come back from the machine shop. Maybe get to work on the front end in the meantime?

[raygreenwood]

Yep....that will keep you busy!
Ray

[heimlich]

I have rods(rebuilt), crank (ground), and pistons(new). You may just be able to reuse yours. When do you plan on cracking the case?
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[Danno5]

When I have heads rebuilt to stick on it I will be saving up for the camshaft that Ray recommended. Every single one of my lifters are concave now so I imagine when I go in I will also find a junk camshaft to match those worn lifters.

[heimlich]

Those web cams do look nice. You can even custom order them.

Make sure to get some nice valves for the heads. The metal in some of the aftermarket valves are quite soft so ask around.
_________________
www.vwnos.com [email protected]
Classic Brands. Classic Quality.
Not all parts are made the same. NOS OE/OEM parts made mainly in West Germany, Early Germany, and Early Brazil are where VW produced the best quality parts and best fitting products.
5% Off your order with coupon code: 5%OFF
Restored Distributors Available (<--Click here)

[raygreenwood]

[Danno5]

Back at it. MOFOCO did the heads as specified. They came back just before the pandemic hit and looked beautiful.

I got back to work on disassembly to check out the pistons/cylinders and case internals.

Pistons 1-3 came out flawlessly. A little hard to to get the wrist pins out with all the old carbon/varnish buildup but that is all. Then I get to #4 and things got tight with that GD oil cooler base in the way. Skip to the ending, I dropped the #4 piston on the floor and cracked the skirt. Original 1.7L domed pistons that at least superficially looked fine.

I considered sticking my head under the 412 and kicking the jackstand out. Its the next day and I'm still here so don't call 911 for me. I am going out to get some of that gym flooring stuff to protect my VW from me though.

[Danno5]

I have a cylinder question for all. If you read above you will know I screwed up royally and cracked a piston skirt. I picked up NOS pistons with no cylinders. Thanks Heimlich for the great service on the pistons!

My question: Should I reuse the cylinders in my current rebuild or should they be stored away as spares?

Cylinder Condition:
1. They are VW and have part numbers stamped that match the Type 4 parts book, so not aftermarket cylinders.
2. Superficially internally and externally they look fine. No gouges, grooves, or weird marks based on comparisons I can make with other threads here. Two cylinders do have some discoloration that won't come off with solvent. No broken fins externally. Some honing marks are still visible
3. Some of the basic feeler-gauge-ring-in-cylinder measurements from the Type 4 factory service manual (german for Cylinder is Zylinder!) still check out OK, although some rings were getting .3 mm from their wear limit (.6 mm vs. .94mm wear limit).

My skill and tools
1. I don't have a dial bore gauge so I can't do the real-deal taper/out-of-round measurements without shelling out for tools.

2. I also would have to get a junk cylinder and honing equipment to learn honing or send it out.

Thanks!
Dan[/b]

[nogoodwithusernames]

[raygreenwood]

[Danno5]

Automotive machine shops we have in the KC area, but not air-cooled shops.

Is this one of those jobs that is air-cooled specific or can a regular shop handle it?

[nogoodwithusernames]

[raygreenwood]

[Danno5]

Ah, bueno. I saw some of the different plates people make to torque down the cylinders. Had no idea before I looked into those threads, but the idea is logical and makes sense to me.

[Danno5]

This tab on the breather tower snapped off when I was trying to separate the case halves.

Can this be welded or have I just doomed myself to getting a new case?

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