73 Mike
I'll drive it someday
My new block just got finished at the machine shop. They ended up decking it slightly past zero to get rid of the o-ring groves in the cylinders. With a stock piston height, they should be approximately 10 thou above the deck.
I have a number of options but little experience in this area so am looking for input.
Option 1: Purchase custom pistons with a shorter compression height. Other than the cost, which isn't all that outlandish, this would seem to be the simplest solution. I am a little concerned about going this route without being able to accurately mock up the engine (see below).
Option 2: Simply use a slightly thicker head gasket. This is a Motown 400 block with a 4.185 finished bore. Not hard to find head gaskets ranging up to 060 compressed thickness. Plenty of room. I've just never done this before so it makes me nervous. This certainly would be the least expensive solution and would alow me to purchase stock pistons and put the motor together to see how far out of the bore they end up.
Option 3: Purchase stock height pistons and have the machine shop fly cut the tops. This has the advantage of an accurate mock up but is the most expensive of the three. I'm also a little concerned about reducing the size of the top ring land.
The reason that I can't accurately mock the engine up ahead of time is that 4.185 pistons aren't lying around my shop. I suppose I could buy one hypereutectic from Summit to check all bores. Using the 4.030's that I have would only give a rough estimate. I do plan to go with forged pistons for the final build.
As always, thanks for the input.
I have a number of options but little experience in this area so am looking for input.
Option 1: Purchase custom pistons with a shorter compression height. Other than the cost, which isn't all that outlandish, this would seem to be the simplest solution. I am a little concerned about going this route without being able to accurately mock up the engine (see below).
Option 2: Simply use a slightly thicker head gasket. This is a Motown 400 block with a 4.185 finished bore. Not hard to find head gaskets ranging up to 060 compressed thickness. Plenty of room. I've just never done this before so it makes me nervous. This certainly would be the least expensive solution and would alow me to purchase stock pistons and put the motor together to see how far out of the bore they end up.
Option 3: Purchase stock height pistons and have the machine shop fly cut the tops. This has the advantage of an accurate mock up but is the most expensive of the three. I'm also a little concerned about reducing the size of the top ring land.
The reason that I can't accurately mock the engine up ahead of time is that 4.185 pistons aren't lying around my shop. I suppose I could buy one hypereutectic from Summit to check all bores. Using the 4.030's that I have would only give a rough estimate. I do plan to go with forged pistons for the final build.
As always, thanks for the input.
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Agreed....I did a Pontiac like that years ago, lasted forever...
