Head Sealing Rings

[dkretz]

I'm rebuilding a 1.7 using 96's which came in the car. While looking in Calif. for the head sealing rings I was told I don't need them. Go metal to metal. Head to cylinder. Is this correct?? Won't this reduced space change the deck height and the CR??

[michel richard]

Speaking of which,

I have a 2.0L which is stock, except that I used european pistons when I rebuilt it. But I also have some 96s from another engine that I bought. Can those pistons and cylinders be fitted to the 2.0 ? Compression would go up, especially if sealing rings are not used.

[Dave at Pelican Parts]

This, I am told, is relatively common Type IV Bus practice. I'm sure that Bob Hoover has something to say on the subject, check www.type2.com .

It *does* affect the deck height and compression ratio. Heck height changes by the height of the squished metal "gasket", as you might expect. However, CR changes are bigger than I would have thought. On one motor, the difference was about 0.3 points! Just from leaving those rings out.

If you want to be sure of your CR, then you have to measure the volume of your combustion chambers (all of 'em!), the dish on your pistons (if any), etc. Then you can do the math of volume at BDC divided by volume at TDC.

--DD

[JP Noonan]

To D. Kretz: Check out the tech section (not the tech articles) Waynes answers your question, you don't need them and in fact they may give you sealing problems. As for the space... This involes building an engine correctly. Check out Tom Wilsons book "How to rebuild air cooled VW engines" I think Borders has it (I bought mine through Barnes and Noble online). If you leave out the head gaskets and your comp ratio becomes too high (after, of coarse, checking deck hight with a false cylinder head and dial indicator) then you can place a base shim between the cylinder and block. Check out Bob Hoover for more info like useing only one shim of the right hieght and not to "stack" shims.

To M. Richard: Take a caliper and check the ouyside diameter of the jugs. Compare it to the inside dia. of the head. The 96mm 1.7L has a smaller size than the 1.8 and 2.0. You can cut a 1.7L head to accept a 1.8 /2.0 jug but a 1.7L jug will be too small for 1.8/2.0 heads. All type IV engines have the same block (called the "spiggot" bore) hole size so any jug (cylinder) will fit in any block.