sealing rings

rich · rich's Garage

use them or not? I was digging through a pile of heads and noticed a 2.0 bus head core I have. After closer examination I found that there were three sealing rings stacked in one cylinder seating area. Is there a reason for this? Or did the last builder just screw up. Are these needed?

JP Noonan · 06-05-1999, 05:10 PM

If you mean there were 3 shims between the cylinder and the block then they were used to increase the combustion chamber volume to match the compression ratio between cylinders. This isn't the best way to go, the more shims, the better chance for a leak. This is why they make different thickness shims. Instead of using three .020" shims you should use one .060" base shim. (Bob Hoover)

If they were head sealing gaskets between the head and the liner I would say the builder screwed up. This is a bad way to build a motor. I'm suprised the liner came off the head. I had a bus linder that WOULD NOT BUDGE because it had leaked at the head for so long.

Are they needed? Well VW wasn't in the habit of doing un-needed things, but many people have had success leaving these out during a rebuild (espesially on 1.7L big bore kits) to actually IMPROVE sealing (and it also boosts compression). So if you are using new liners and the heads are either in good shape, or have just been machined, then I would say to leave them out.

djs · 06-05-1999, 07:55 PM

I agree. I left the sealing rings out on both my 82 Vanagon 2.0 and my 914 2.0, and have had no problems after many years.

However, if these rings are between the cylinders and case, then they are there for proper deck height clearance and/or combustion chamber adjustment.

On my Vanagon, I installed a 2.2L modified engine from Mark Stephens. The increased displacement in this motor comes from a greater stroke, rather than increased bore. To compensate for the increased stroke, 3/32" spacers were inserted between the cylinders and case to maintain the correct deck height and compression ratio. This effectively allows use of the stock pistons and cylinders.

jmcleod · 06-07-1999, 07:31 AM

interesting, i rebuilt a 81 vanagon in which, after asking the local mechanic, i put the sealing rings (between head and cylinder) in, (no leak after 13k mi) and put sealing rings in a 914 2.0L (no leak after 200 miles). i saw a bulletin published by vw that stated to omit the sealing rings, but i followed the advise of the local type 4 expert instead of the factory.