I was talking to a friend the other day. He said he was about to start on his race engine, as soon as he found someone to make him some spacers. I told him about a good local shop assuming he was talking about carborator spacers. He said no, he was talking about head spacers. Double gasketing a plate made to extend the cylinder volume. Doing this a larger stroke could be used or larger rods could be used to raise the rod ratio. I guess the deck clearence is basicly ignored and the piston can be brought up to right before the piston ring would contact the bottom gasket.

I don't see why this shouldn't work if done correctly, but I've never heard of it. My question is, is it worth it. I don't know what the thickness of the plate, or the stroke or sizes of the rods. He just told me it was bored .060" over.
Would this be a risk worth taking?

 

There are instances where something like this would work, but you're not going to raise the deck of the block a huge amount.

Kaasse did this in his 2004 Engine Masters motor with a 3/8 thick head gasket. Then again his top ring was about .400+ down the piston.

If you were going to raise it considerably and run the piston rings up into the spacer then you should probably install a sleeve thru the spacer to maintain ring seal, that's about the only way I can see that it's possible.

Bret

 

I thought about this a long time ago using an LT1 but you would definetly have to use sleeves but you would also be tearing into the waterjackets. It would be cheaper just to buy a bigger block.

 

Never thought of that... Thats a lot of extra machine work, but it's a good idea.
I think his plan was to use a piston, like the one you mentioned with a considerable distance to the first ring and then he'd probably leave about .020"
between the ring at piston TDC and gasket.

 

Spend the bucks and get an after market tall deck block. To much brain damage otherwise.

 

Well yeah that would be the best way of doing it, but it may be hard to find.