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Can anybody of knowledge help me please ?

Could someone let me into the secret of why, HC cast pistons (22661-99a) are not compatible with SE PRO heads.
Is it possible that the construction is not robust enough for high RPM ?
If this was the case, surely the easy solution is to dial in a lower RPM limit.

Or is it because of valve clearances etc etc.

Many Thanks in advance.
 

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clive_frog said:
Can anybody of knowledge help me please ?

Could someone let me into the secret of why, HC cast pistons (22661-99a) are not compatible with SE PRO heads.
Is it possible that the construction is not robust enough for high RPM ?
If this was the case, surely the easy solution is to dial in a lower RPM limit.

Or is it because of valve clearances etc etc.

Many Thanks in advance.
The primary reason as I know it is because the SE Perf heads have a reduced combustion chamber size. The SE Perf heads are designed to be used with flat top pistons and yield a 10:1 compression ratio. The SE Cast Hi Comp pistons are designed to use a STOCK size combustion chamber and yield a 10.25:1 compression ratio. Assuming the dome on the piston doesn't hit anything, the combination of the reduced size combustion chambers and domed pistons would put the compression ratio over 11.5:1. This is WAY too much for a Cast piston. Not to mention it will ping itself to death.

Rather than reinventing the wheel, use combinations that work together correctly and you won't have any problems.
 

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springer- said:
The primary reason as I know it is because the SE Perf heads have a reduced combustion chamber size. The SE Perf heads are designed to be used with flat top pistons and yield a 10:1 compression ratio. The SE Cast Hi Comp pistons are designed to use a STOCK size combustion chamber and yield a 10.25:1 compression ratio. Assuming the dome on the piston doesn't hit anything, the combination of the reduced size combustion chambers and domed pistons would put the compression ratio over 11.5:1. This is WAY too much for a Cast piston. Not to mention it will ping itself to death.

Rather than reinventing the wheel, use combinations that work together correctly and you won't have any problems.
Whats the Highest Compression You can Run with Cast Pistons????
 

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DanNZ said:
Whats the Highest Compression You can Run with Cast Pistons????
Since the SE Hi-Comp 10.25:1 pistons are cast, and I have always used 10.5 as a max, I would say 10.25:1. SE hi-comp pistons at 10.5:1 are forged. The other limiting factors are Max RPM should not be over 6200 and Cast pistons should not be used with Boost of any kind, turbos, blowers and nitrous.
 
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