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Tcash Samba Member
Joined: July 20, 2011 Posts: 12844 Location: San Jose, California, USA
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Posted: Tue May 12, 2015 8:13 am Post subject: |
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Leiif wrote: |
The "Q" is actually a very nice head. I am torn between it or the AMC as a spare.
That is a nice looking casting.
Someone put spacers/washers under the springs. I assume that is to boost the pressure?
Those are to adjust the installed spring height. Keep them in order. |
good luck
Tcash |
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SGKent Samba Member
Joined: October 30, 2007 Posts: 41031 Location: Citrus Heights CA (Near Sacramento)
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Posted: Tue May 12, 2015 11:23 am Post subject: |
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Leiif wrote: |
The "Q" is actually a very nice head. I am torn between it or the AMC as a spare.
Someone put spacers/washers under the springs. I assume that is to boost the pressure? |
it is because the valves were ground once already so they sit deeper making the springs longer than the correct installed height. It makes up for the lost metal when grinding them. _________________ “Most people don’t know what they’re doing, and a lot of them are really good at it.” - George Carlin |
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Leiif Samba Member
Joined: August 25, 2008 Posts: 95 Location: FL
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Posted: Thu May 14, 2015 2:14 pm Post subject: |
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Thanks again for the comments.
I have another question. I bought Curil K2, Curil T, Durko, Loctite PST 565, and Loctite 518, where is each used? So far I have used the K2 on the case, the 565 on the threads for the case and the Dirko on the oil galley plugs. My understanding is that the Curil T is to be used on the cylinder shims, nothing is used on the actual head to cylinder, and the 518 is used for the exhaust connection to the head. Does that sound right?
What about the oil filler tube, oil pump, oil filter connection, oil cooler and the push rod tube seals? Which sealant if any for those? |
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Leiif Samba Member
Joined: August 25, 2008 Posts: 95 Location: FL
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Posted: Sat May 16, 2015 10:26 am Post subject: |
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The new valves are in. I do not have much room with this set-up as far as CR is concerned. My combustion chambers measure 54cc and the dish measures 8.5cc giving me a total of 62.5cc. My deck height on first check was .026 with no shims. If I add a .010 I end up with .036 and a CR of 7.5. Adding a .020 shim drops me to 7.3 CR. With this cam I think it might be best to keep the 7.5 CR. The deck height is small but close to .040.
So, .010 and .036 deck ht. @ 7.5 CR or .020 and .046 deck ht. @ 7.3 CR ?
(edited to reflect deck ht change with new bearings)
Remember I am using a Scat C25 cam.
Scat C25 stock lifters are 1.3 = .455 lift
Cam Lift ------ .350
Adv Dur ------ 272
Dur @ .050 ------ 238
In @ .05 ------ open 11 BT - close 47 AB
ex @ .05 ------ open 47 BB - close 11 AT
lobe center ------ 108
Any thoughts? Anyone?
Last edited by Leiif on Sat May 16, 2015 12:55 pm; edited 4 times in total |
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Leiif Samba Member
Joined: August 25, 2008 Posts: 95 Location: FL
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Posted: Sat May 16, 2015 11:21 am Post subject: |
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Another issue I came across is that in the Bentley it says to make sure the forged marks on the rods are facing up. My rods do not have the forged bumps they are talking about. I did notice that the image showing this was stamped 1972. Does a 74 have a particular way the rod must be installed? Numbers up down or what? |
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Leiif Samba Member
Joined: August 25, 2008 Posts: 95 Location: FL
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Posted: Sat May 16, 2015 1:00 pm Post subject: |
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Just to catch up a bit:
I will be using the 4 up front. The 2 at back on the left will be spares and the one on right is a paper weight.
These were done before I bought the SS exhaust valves:
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Leiif Samba Member
Joined: August 25, 2008 Posts: 95 Location: FL
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Posted: Sat May 16, 2015 1:08 pm Post subject: |
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So when I bought the matching S head I got a Q and a J also. Thought I was getting 2 Q's. These images are from a bit of what I did to those heads. They may be for sale after I get one more stud that is on order:
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Leiif Samba Member
Joined: August 25, 2008 Posts: 95 Location: FL
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Posted: Sat May 16, 2015 1:33 pm Post subject: |
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The questions from earlier are of utmost importance:
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... I bought Curil K2, Curil T, Durko, Loctite PST 565, and Loctite 518, where is each used? So far I have used the K2 on the case, the 565 on the threads for the case and the Dirko on the oil galley plugs. My understanding is that the Curil T is to be used on the cylinder shims, nothing is used on the actual head to cylinder, and the 518 is used for the exhaust connection to the head. Does that sound right?
What about the oil filler tube, oil pump, oil filter connection, oil cooler and the push rod tube seals? Which sealant if any for those?
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The new valves are in. I do not have much room with this set-up as far as CR is concerned. My combustion chambers measure 54cc and the dish measures 8.5cc giving me a total of 62.5cc. My deck height on first check was .026 with no shims. If I add a .010 I end up with .036 and a CR of 7.5. Adding a .020 shim drops me to 7.3 CR. With this cam I think it might be best to keep the 7.5 CR. The deck height is small but close to .040.
So, .010 and .036 deck ht. @ 7.5 CR or .020 and .046 deck ht. @ 7.3 CR ?
(edited to reflect deck ht change with new bearings)
Remember I am using a Scat C25 cam.
Scat C25 stock lifters are 1.3 = .455 lift
Cam Lift ------ .350
Adv Dur ------ 272
Dur @ .050 ------ 238
In @ .05 ------ open 11 BT - close 47 AB
ex @ .05 ------ open 47 BB - close 11 AT
lobe center ------ 108
Any thoughts? Anyone?
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Another issue I came across is that in the Bentley it says to make sure the forged marks on the rods are facing up. My rods do not have the forged bumps they are talking about. I did notice that the image showing this was stamped 1972. Does a 74 have a particular way the rod must be installed? Numbers up down or what?
Any and all help appreciated,
Leiif |
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Tcash Samba Member
Joined: July 20, 2011 Posts: 12844 Location: San Jose, California, USA
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Posted: Sat May 16, 2015 1:37 pm Post subject: |
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Leiif wrote: |
Another issue I came across is that in the Bentley it says to make sure the forged marks on the rods are facing up. My rods do not have the forged bumps they are talking about. I did notice that the image showing this was stamped 1972. Does a 74 have a particular way the rod must be installed? Numbers up down or what? |
That is a type I crank in the picture. Type IV rods are symmetrical and can go on either way. I like to put the numbers facing up. That way when I do the drop test. I can lift the rods from the side and double check the numbers are lined up before I drop the rod ends. They should all drop evenly.
If you are going to run a tight deck height. You need to check the valve to piston clearance with some clay or Play-Doh.
You need to get the Tom Wilson book.
Tcash wrote: |
Might I suggest you purchase this book.
How to Rebuild Your Volkswagen air-Cooled Engine - Tom Wilson
Publisher Penguin, 1987. ISBN 0895862255, 9780895862259
It describes in great detail all the steps of rebuilding a air cooled VW engine. Read and understand it completely. Don't be afraid to ask questions.
Good Luck
Tcash |
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Leiif Samba Member
Joined: August 25, 2008 Posts: 95 Location: FL
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Posted: Sat May 16, 2015 2:00 pm Post subject: |
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In order to do that it sounds like I would need to do a total mock-up including cutting the pushrods to length. Then if something needs changing I will need new pushrods??? |
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Bleyseng Samba Member
Joined: July 03, 2005 Posts: 4752 Location: Seattle
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Posted: Sat May 16, 2015 2:11 pm Post subject: |
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You should be good but it's worth checking.
Check the amount of lift and the rocker arm angle so you check the valve train geometry. Cutting the pushrods is part of that "if" is off. I doubt it is in your case as everything is basically stock stuff and not hacked.
7.5 to 1CR is fine as is .040 deck ht as it "should" run efficiently with that tight deck. _________________ 70 Ghia Black convert-9/69 build date-stock w/133k 1600 SP-barn find now with a rebuilt tranny and engine
77 Westy 2.0L w/Ljet, Camper Special engine-95hp and with LSD!(sold)
76 Porsche 914 2.1L L20c, 120hp Djet (sold)
87 Syncro Westy Titan Red 2.1L 2 knob 100k miles |
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Tcash Samba Member
Joined: July 20, 2011 Posts: 12844 Location: San Jose, California, USA
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Posted: Sat May 16, 2015 2:23 pm Post subject: |
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Leiif wrote: |
In order to do that it sounds like I would need to do a total mock-up including cutting the pushrods to length. Then if something needs changing I will need new pushrods??? |
Only if your crank is stroked. In which case you would use the adjustable pushrod you use to determine pushrod lengths.
Tcash |
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Leiif Samba Member
Joined: August 25, 2008 Posts: 95 Location: FL
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Posted: Sat May 16, 2015 4:46 pm Post subject: |
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Thanks Tcash and Bleyseng,
It is stock as are the bearings. The only big changes are the cam and a 30mm oil pump. There are a lot of other smaller changes but nothing hacked. EMPI exhaust, solid rocker spacers, chromoly pushrods, high pressure relief valve, SS exhaust valves and probably a few things I can't think of right now.
What is the minimum for valve to piston? |
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Leiif Samba Member
Joined: August 25, 2008 Posts: 95 Location: FL
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Posted: Mon May 18, 2015 4:56 pm Post subject: |
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When you look closely at the valves you see a line on the inside edge. That is where I took the edge off the valve. Supposedly that sharp corner creates a bit of turbulence and removing it improves flow. It doesn't look like much but it is very noticeable to feel. I did the same to the brand new SS valves.
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Leiif Samba Member
Joined: August 25, 2008 Posts: 95 Location: FL
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Posted: Mon May 18, 2015 6:31 pm Post subject: |
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I did do the valve to piston test. Be warned that play doh is made with a lot of salt and you don't want to leave it in there long. Aluminum does not like salt. My test showed it to be between 1/8 and 3/16 which is well within the .1 that was the minimum recommended by Scat.
More tomorrow |
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Leiif Samba Member
Joined: August 25, 2008 Posts: 95 Location: FL
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Posted: Tue May 19, 2015 3:54 am Post subject: |
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As I am posting to 2 different forums I am getting suggestions from both. I have taken them an applied them when I can. I have had the heads on and off multiple times and it looks like I need to do it at least one more time to check all the ring gaps.
My 1,2 side is a lot tighter than the 3,4 side. Admittedly I didn't check all the rings. I think that was a mistake.
Theoretical question. If 1,2 need the ring gaps widened then they would be smaller overall. Would it be better to swap the 2 and 4 so the firing order would be small, large, small, large, with the small, large opposing. As they are it will be small, large, large, small with the large on one side and the small the other. I think switching the 2 and 4 cylinders and rings would be smoother. Anyone know for certain?
I may do the Ghetto Oven Test while I have the heads off. What temp and for how long? |
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Leiif Samba Member
Joined: August 25, 2008 Posts: 95 Location: FL
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Posted: Tue May 19, 2015 5:43 am Post subject: |
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Anyone here ever do the "Ghetto Oven Test"? Ever run an engine with heads that pass? How many miles? |
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Leiif Samba Member
Joined: August 25, 2008 Posts: 95 Location: FL
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Posted: Tue May 19, 2015 8:18 am Post subject: |
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So I took the 1,2 side apart and checked the ring gap. All were good. Then I checked the grooves. Uh oh, there was still carbon in there. Thought I did a good job before since I got soooo much junk out. Not good enough for new rings. That made all the difference. |
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Leiif Samba Member
Joined: August 25, 2008 Posts: 95 Location: FL
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Posted: Tue May 19, 2015 10:44 am Post subject: |
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I had some crap threads and fixed those. Staggered the drilling and put in some e-z lok inserts.
Keeping it lined up with the other stud.
Tape is for depth. Used it on the drill bits also. Be careful.
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Leiif Samba Member
Joined: August 25, 2008 Posts: 95 Location: FL
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Posted: Tue May 19, 2015 1:02 pm Post subject: Using a cheapo valve spring compressor. |
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Not that I am an expert but here is a short tutorial on using a cheapo valve spring compressor, with a small trick that may help someone else. These are the junky ones you rent from Autozone. There was a much nicer one at Carquest but I would have to buy that one. I may anyway after using this thing.
These springs are dangerous. Wear eye-protection and gloves. Your flesh means nothing to the spring.
Things you will need:
This little exercise was done on a J head:
To get the valves to stay in place and make the valves level I used the short blocks of wood and a longer one on those. It is a little wobbly but this is the cheap version:
Let some penetrating oil soak into the keepers:
At first don't try and take the whole thing:
Squeeze the spring enough to get it loose then gently, or maybe not so gently whack the tool top to loosen the keeper:
Then your keeper should be loose. You can't get it yet but it will be easier to get at the next stage with it loose:
Next insert an 8mm nut or whatever in between the springs about an inch from where it comes together. This helps you get the full bite on the spring:
I get that spring off as soon as the keepers are out and cover it with a rag as I loosen the spring. This really helps reduce velocity if the spring pops before you get it all the way loose:
Then you have the spring off. Clean and deburr if needed before removing the actual valve.:
When you are using this particular tool you don't want it all nice and straight and even. It works best all cockeyed like this. Sooner or later you will have all the valves off. Sometimes it takes 3 to 5 minutes for a valve and sometimes 30 or more:
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