zero decking the block

andy669 · 03-27-2006, 09:54 AM

For maximum compression its better to run the pistons .005~.007 in the hole and select a small bore head gasket thats .030 thick. Or with an iron head you can have the pistons .020 in the hole and use a .015 steel shim gasket. Zero decking with a .037 gasket can give up a little because the bore size of the gasket is always bigger than the piston. But to do this accurately you need to have the block deck trued. This brings the deck perfectly parrallel with the mains, and makes sure both decks are set at 45 degrees. I have seen them be out as much as .020 from front to back and top to bottom.

Andy

~The Jester~ · 03-29-2006, 06:36 AM

This is really interesting, two of the guys opinions I respect the most on this board (Jeff & Andy) have different ideas on this.

I ALWAYS take the "twist" out of my blocks, and since it's at the machine shop on the right machine, I've always taken them to zero deck, talking hot rods here, not daily driver engines I've built.

Andy brings up a good point though, if you read that closely and invision what he's saying there, it makes sense. Funny what comes out of the woodwoork when you're talking to guys that are in a heads up class, have rules to follow, and are trying to squeeze every ounce of power out of an engine!

Great thread going on here!

03-27-2006, 09:54 AM	#1
andy669 Registered Member Join Date: Jan 2001 Location: Moline Il Posts: 901	Re: zero decking the block For maximum compression its better to run the pistons .005~.007 in the hole and select a small bore head gasket thats .030 thick. Or with an iron head you can have the pistons .020 in the hole and use a .015 steel shim gasket. Zero decking with a .037 gasket can give up a little because the bore size of the gasket is always bigger than the piston. But to do this accurately you need to have the block deck trued. This brings the deck perfectly parrallel with the mains, and makes sure both decks are set at 45 degrees. I have seen them be out as much as .020 from front to back and top to bottom. Andy __________________ 88 coupe 91 LX NMRA Pure Street 5120

03-29-2006, 06:36 AM	#2
~The Jester~ Rat Killer Join Date: Aug 2002 Location: Cold ass Ohio Posts: 1,143	Re: zero decking the block This is really interesting, two of the guys opinions I respect the most on this board (Jeff & Andy) have different ideas on this. I ALWAYS take the "twist" out of my blocks, and since it's at the machine shop on the right machine, I've always taken them to zero deck, talking hot rods here, not daily driver engines I've built. Andy brings up a good point though, if you read that closely and invision what he's saying there, it makes sense. Funny what comes out of the woodwoork when you're talking to guys that are in a heads up class, have rules to follow, and are trying to squeeze every ounce of power out of an engine! Great thread going on here! __________________ d-Con Racing "Nothing fancy, just 347 inches of RAT POISON!" MICE need not apply.....

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