I've always heard that hypereutetic pistons were made to be equipped with computer controlled car. (EFI) But i'm not building anything close to computer controlled, so what do they me by hypereutetic? Are they for computer controlled or smogger engines?

 

It's just the type of material and the way it was casted. You can use them with either computer controled, smog, or carbed motors.
Hypernumatic is an alloy whose chemical composition is above that of the eutectic. In hypereutectic Al-Si alloys, the first phase to form on solidification is primary Si. Phosphorus-based additives are often used to refine it.

So pretty much it's an aluminum/silcione piston.

 

stay away from hypereutectic pistons, a tuning mistake can cause them to shatter. they are not made for high performance applications. BTW ... "thats controlled" mister grammer. quit correcting people if you can't spell yourself. Sick

 

Sorry about the spelling I was in a hurry. Anyway the 350 i'm building will only be 350 or 375 hp and will be about 10.25.1 compression; so will hypereutectic pistions be fine? Or should I go with regular alunimum cast pistons?
THX

 

69camaro1
Hypereutetic pistons are only a "better" cast piston. Is most circumstances, they will hold up better than a regular cast piston because of their higher silicone content which make them withstand heat better. Any cast piston can shatter when put under extreme stress. Therefore, the hypereutectic is better suited to most cast piston application needs.

 

it wasn't you i was referring to 69 he knows who i'm talking about. Sick

 

Oh ok. Thx for all the help I'll be going with the hypereutectic pistons. By the way if you ever look in Jegs the regular cast pistons are the same price as the hypereutectic pistons. So theres no point in even bothering with regular cast. By the way it will be fine running on pump 89 won't it?

 

you may want to at least use 91 octane, better safe than sorry.

 

To high of compression to run on 89, my opinion

 

91 or 93 is better for the motor, anyway, since they're required to have higher detergent levels than regular unleaded.