hyperutechtic pistons...anyone know about them????
#14
Re: hyperutechtic pistons...anyone know about them????
Ok, so would these pistons be of any use to a honda owner? Are they availabe for the Bseries motors? Would they work with stock rods? Forged rods? What HP are they good to? And how much $$$ and where from
#17
Re: hyperutechtic pistons...anyone know about them????
Originally Posted by Cadracer
The thing with these pistons are that they dont like any detonation.If detonation occurs i havent seen or heard of a set living.They shatter like glass. My 2 cents worth
#18
Re: hyperutechtic pistons...anyone know about them????
Originally Posted by random-strike
Originally Posted by Ravage70
Originally Posted by fork
stronger than cast, not as strong as forged but they don't grow and shrink with heat like forged do, so you don't get the cold start piston slap
with enough mileage the cylinder walls wear which will cause piston slapparoos
#19
Re: hyperutechtic pistons...anyone know about them????
Hypereutectic refers to the fact that due to grain orientation in metals, there is only so much of a certain alloying agent that can be added to a metal that will actually form a solid 'metallic atomic bond' within the crystalline structure. This theoretical maximum is called the eutectic point of the alloy. Any alloying agent added past this point doesn't really bond very well and is more or less just chilling there. In this case, when alloying aluminum and silicon, the eutectic point is somewhere near 12.5% silicon. A common hypereutectic alloy is 390 aluminum (made famous by the Chevrolet Vega) which works well for this application. This alloy is somewhere near 14%, or something, I have had a lot to drink... anyway, the extra silicon is killer for scuff resistance on a cylinder wall. Not to mention the real reason for they alloying in the first place- if you fill in the crystalline structure of a metal, it gets more rigid. Pistons hold their shape better, face less thermal expansion/contraction because simply, the grains can't slide past each other as easily if they are subject to more atomic bonding, and as a tradeoff are indeed more brittle as the percentage of alloying agent increases up to the eutectic point. As compared to 2618 T61 alloys (the noisy, slappy ones with ~2% silicon) hypereutectic alloys aren't really that weak as far as absolute tensile strength (you can rev the ---- out of them still) but they do indeed suffer more than a more ductile 2618 T61 when detonated on. I dig 4032 T6 alloy. It makes a pretty good compromise as it is right at the eutectic point. That's what you will find in my car. -Peace