Just thought I'd let you guys know that summit is selling sets of Keith Black hypereutectic pistons in a .030" overbore for the 350 for $69 a set. I just ordered some, and it's not a typo on the website. Part number is UEM-1436030-8

 

Let me know what you think about the quality when you get them.

 

Have used KB before on couple of mtr's. Good pistons but make sure and gap rings like they say or there will be problems. Despite the rumors they can handle nitrous they advertise a 1,000 horse nitrous.

 

Do you know the gap specs for these particular pistons? Top two rings are 5/64" and the oil ring is 3/16" if it helps. I only want to put a little bit of juice on it. Less than a 150 shot.

 

According to the the KB catalog ring end gap for street nitrous and supercharged is .0080.

 

Figures, i just paid $320 for a set of KB's, .30 over.

 

They have two grades of pistons. You bought the standard
grade which is equal to most hypereutectic pistons on the
market. The better one is UEM-KB106030-8, which is their
signature series and is basicly the same piston but made from
390 alloy and heat treated to T6 hardness which may be the
closest thing you can get to a forged piston. It also has spiral
lock grooves for use with floating pins and a few other goodies
but runs like $175 for a set. Still cheap for what they are.

 

What are the benefits of hyperutectic pistons and of forged?

 

hyper pistons are stronger than cast pistons, but are pretty brittle. Forged pistons are much stronger than hyper pistons, but are also much more expensive. Forged pistons also tend to have a higher expansion rate, so you can get a little piston slap until the car warms up, although I don't have that problem with mine.

 

I am not a metallurgist or anything but I would think that the
390 alloy heat treated to T6 would raise the tinsel strenght
high enough that it would be impossible to crack no matter
what you did to it. Possibly making it equal to or superior
than a forged piston for everyday street performance.