Hello everyone,
Today while beginning the assembly of my engine (F22b2 bottom end, F22a1 head, with 86mm arias 8.2:1 CR pistons, Darton dry sleeves) I realized I have an issue. My piston-to-head clearance is not enough, actually its negative, which means if I had tried to assemble the engine as-is the pistons would hit the cylinder head as soon as I would have rotated the crank.
Anyway, I just got my block back from the machine shop to have the Darton dry sleeves installed, and also had the cylinder head decked. During the machining obviously enough material was taken off to take away that clearance which is needed for obvious reasons.
I would imagine the simplest was to fix this now is to get a slightly thicker head gasket to accomodate that spacing there that I need, am I correct in my thinking here? Getting a new thicker head gasket shouldnt be too hard, but what I need to figure out is the ideal piston-to-head clearance should be, so I can calculate what head gasket I need to get, and so the engine performs the way it should without any big issues!
EDIT: 4/14/12 I ended up machining the top of my pistons, Read on for more info!!
If anyone can give me any suggestions on this that would be greatly appreciated! Also if anyone has any idea what the stock piston-to-head clearance on our engines are, that would be a great help also.
Block: F22b2 - essentially identical to the F22a1, a4, a6.
Head: F22a1
Current head gasket - MLS .030" - not enough!
Arias pistons 86mm 8.2:1 compression ratio
Car is turbocharged currently - DSM 16g setup- with future plans to re-introduce the nitrous oxide.
Here you can see my clearance issue. Note: this is exactly at top dead center.:
If i measure that clearance above, which is how far the piston extends from the block I get this, which when added together is .037"
And a quick pic of the Darton dry sleeves
Today while beginning the assembly of my engine (F22b2 bottom end, F22a1 head, with 86mm arias 8.2:1 CR pistons, Darton dry sleeves) I realized I have an issue. My piston-to-head clearance is not enough, actually its negative, which means if I had tried to assemble the engine as-is the pistons would hit the cylinder head as soon as I would have rotated the crank.
Anyway, I just got my block back from the machine shop to have the Darton dry sleeves installed, and also had the cylinder head decked. During the machining obviously enough material was taken off to take away that clearance which is needed for obvious reasons.
I would imagine the simplest was to fix this now is to get a slightly thicker head gasket to accomodate that spacing there that I need, am I correct in my thinking here? Getting a new thicker head gasket shouldnt be too hard, but what I need to figure out is the ideal piston-to-head clearance should be, so I can calculate what head gasket I need to get, and so the engine performs the way it should without any big issues!
EDIT: 4/14/12 I ended up machining the top of my pistons, Read on for more info!!
If anyone can give me any suggestions on this that would be greatly appreciated! Also if anyone has any idea what the stock piston-to-head clearance on our engines are, that would be a great help also.
Block: F22b2 - essentially identical to the F22a1, a4, a6.
Head: F22a1
Current head gasket - MLS .030" - not enough!
Arias pistons 86mm 8.2:1 compression ratio
Car is turbocharged currently - DSM 16g setup- with future plans to re-introduce the nitrous oxide.
Here you can see my clearance issue. Note: this is exactly at top dead center.:
If i measure that clearance above, which is how far the piston extends from the block I get this, which when added together is .037"
And a quick pic of the Darton dry sleeves
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