383ss

iTrader: (14)

the diamond pistons I got are preclearanced for #8. how safe is this and do you have to custom order pistons in order to not clearance them for a 6.0L iron block 408??

my builder is warning me pretty stongly that this isn't the best idea especially when I put a dual stage 100/100 shot on it.
he clearanced the back boss of my JE pistons for my 383 to a thickness of .095 and the pin was cracking on #8 after 50k miles and about 150 passes.
these diamonds are clearanced to .050 thickness on the pin boss...

is ANYONE else using clearanced pistons for a 4" crank and if so are you spraying or having any issues with it??

Chris@AP-Engineering

iTrader: (-2)

Most people are using Diamonds on this board. We have run a ton of these pistons and have never had a problem. You will be fine. Put it this way we have sprayed 300hp mutiple times on Fstr-thanu's car with out ever having a problem. Call Diamond and see what they say.

Thanks

383ss

iTrader: (14)

thanks for the response. I will call diamond tomorrow, but they are trying to sell thier product. I wanted some real world experience.

thanks!!

you are talking about the off the shelf pistons that are pre-notched, I'm assuming

11 Bravo

iTrader: (3)

Hey 383ss, would you happen to have a pic of your #8? I have a set of Diamonds and understand that the #8 is supposed to be clearanced already, but that it's hard to notice. I cannot tell the difference between my pistons, but maybe a pic would help.

383ss

iTrader: (14)

no pic of #8. it's at the machine shop 3 hrs away. It is clearanced, I'm concerned about how much it effects the strengeth and reliability of it under major abuse.

LOnSLO

iTrader: (15)

The clearancing, on my #8 anyway, was deep enough, but it wasn't far enough over. Had to take the grinder to it. Wasn't fun cutting on a brand new custom nitrous piston.

00blkws6

I had the exact same problem with mine.

racer7088

The area they clearance does not really affect reliability at all. ALL ls1 stroker pistons are either a forger side relief design with a narrow pin there or clearanced there otherwise they won't go in the motor. The number 8 piston is not the one that usually fails in an NOS deal anyway. Don't worry about it as long as you have clearance you will be alright.