Does anybody know what these gaskets are for?

oooh can of worms

they look like the barrel to head sealing rings ..... most say leave them out and lap head to barrel , i was told by Laurie petit to use them if engine originally had them otherwise it messes with deck height and comp. or you could add the thickness under the barrel .

 

Thanks, that sounds logical, it's only had one new head and all four barrels were lapped. That would explain why I've only got two gaskets. Good I can stick them in the extras box and ignore them. If anyone can use them let me know and I'll post them on.

 

Looks about the size of a barrel gasket/spacer. Someone will be able to give you chapter and verse before too long...

Edit to ^what they all said^

 

What are they made of? I've got a pack of 2 about the same size which are for the oil strainer. Made of cardboard though. Yours look metallic so maybe not that.

 

Not the set I have for the 2 litre engine JK part J10351.

 

The last 2L head I bought came with a red sticker that said "DO NOT USE HEAD SHIMS. USING HEAD SHIMS WITH THIS HEAD WILL INVALIDATE THE WARRENTY". Honest guv...
What you say @Paul Weeding ?

 

Newer heads have a 1mm Step left when machined I think

 

Ah I get it, they will have used them for the old head, Doh! I forgot they did a complete rebuild.

 

I say put them in the bin... even if they were originally fitted!! It's not going to change the comp ratio hardly at all!!

Another thing you have to remember, is that fuel quality was a lot lower in the 70s, so comp ratios were set low to cope with varying fuel qualities!!

My engine runs a high (around 10:1) comp ratio, and I have no issues running it around on the road.... towing etc

Another thing you have to watch when mixing new heads with old, is that the new heads have the 1mm step, and the shims aren't 1mm, so you'll be un balancing the engine if the free volumes aren't matched!!

 

You do need them, (unless you use amc heads) as they affect deck height, if you skip them, all will be fine for a little while. As soon as your big and small ends wear in a bit, your piston will start kissing head, ultimately prematurely destroying your engine.

 

to coin a phrase you are referring to a "lawn mower" engine!

 

As long as the deck height isn't below 1.25mm, you don't need them!! And if the deck was below 1.25mm, I'd shim the base of the barrel!!

Even VW did a workshop update to not include them in any engines that had leaking heads!!

Also, if your little and big ends wear that much, then you've done something wrong rebuilding your engine!!

 

If you remove them on the stock engine your deck height will go below safe limit. VW did not advice to remove shim on leaking heads. There was bulletin that was issued to "eliminate seizing of pistons" it advised to (apart from removing the head to cylinder gasket) actually increse deck height by adding the 1.6mm thick shim at the bottom of the cylinder. Just removing the gasket is very bad idea on already minimal deck height spec.
Such misguded information you provide will help no one.

 

Wow, and how many type 4 engines have you built??

 

Ok, quite a lot of opinions here about whether they should be fitted or not so I did what I should have done in the first place, phoned the engine builder. Apparently new cylinder heads are machined so that they do not require gaskets. I have gaskets on my old head and none on my new head, hence why I have two spare.

 

Just as added back up to what I've been saying

http://www.shoptalkforums.com/viewtopic.php?f=1&t=141890&p=1148565&hilit=head shims#p1148565