What type of pistons?

This isnt for a gt40 but i would think it would still be applicable. A friend of mine is building a 383 blower motor and using 6" rods, the only piston he can get other than custom built is a K.B. hypereutectic (spelling???) (that says suitable for a blower) but some guys keep slamming them saying hypers are weak. Now most of the engine building shops around here are pretty hokey so trying to find an informed person to make an unbiased judgement is pretty hard, everyone knows forged are stronger so thats what they say. So, are hypers really bad and not worth the time or are they a good option for someone who mostly street drives with the occasionally weekend beating?
 

Jim Rosenthal

Supporter
I have a book on Ford performance engines by Isaac Martin, I think. The cost difference between hypereutectic pistons (which actually refers to the aluminum alloy from which they are made, not a type of piston, if I am not mistaken) and forged pistons is not all that much. Pistons for blower motors tend to have lower CRs than for naturally aspirated engines, but because of the larger mixture charge from forced induction the cylinder pressures are higher; if I were building a motor and intended to use forced induction I would get the best pistons I could afford. An alternative is to take all the money spent on a blower etc and put it inside the motor and build something sturdier and with a higher CR etc; it may not make as much power as an engine with a blower, but it might run longer...
 
While K.B is a name you can usually rely on, I think for peace of mind that forged pistons would be the way to go. Is the engine fuel injected, or not, and what boost levels are to be run? Mabey low boost, fuel injection you would get away with hyperutectic (spelling?) because of the knock senseing capabilities of the EMS.
 
KB hypereutetic pistons are high quality and can handle
high HP loads. However if serious detonation is possible (always a risk with forced induction), I'd go forged.

MikeD
 
I gave him the suggestions and after a little more digging, he has found that JE do make a piston for him, they just dont advertise it or put it in any catalogs because it isnt popular, go figure.
 
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