I have heard that the KB signature series hyper pistons were considered better than the cheapie TRW or speed pro forged pistons. I am building a 383 stroker on a tight budget and need to save all the money i can. Would the pistons do for a 125-150 shot?

thanks
Shanw

 

They are lighter, but definitely not stronger. I would go with the speed pro's.

 

The KB's are definetly stronger than the stock pistons, but not stronger than the TRW forged. I would definetly do forged if you plan on running alot of juice through your motor.

 

I work for TRW (but not engine components) so I might be a little bias, but from the feedback i hear at work, we have great pistons.


I think TRW and speedpro might be the same - or extremely close anyway. But keith black pistons are MORE than fine for a 125 shot. I wouldn't hesitate for a second to use stock pistons on a 150 shot. KB pistons are conciderably stronger than stock from what i've read here. They aren't nearly as strong as forged though. Forged pistons will ding and dent. KB will explode.

 

well i think i have decided to just use the Speed Pro forged pistons i already have. They are for a 355 and i guess that is what i will build instead of the 383. On a car with stock heads those extra cubes won't give me more than around 30 hp anyway. I would rather run a 150 shot of nitrous than take the 30 extra hp all the time.

Thanks
Shawn

 

If you already have the speed pro's definatly use them. But don't be afraid to use Keith Blacks. I've hit mine countless times with 150/175 shots. I also hit mine by mistake with 275hp (playing with a dual stage LOL). It backfireded & blew of my air filter,blew a head gasket which put pressure on my coolant system which in turn blew my radiator out but the pistons lived.

 

Let me put it this way.

Here's what happens when KB Hypercraptics experience detonation. (This happened on a 150shot)

Piston go boom

nuther angle

Kb's work fine on moderate and sometimes large shots when everthing is going great... But they are going to show you exactly how brittle they are on that occasion when the local gas station has a batch of bad gas, or when your pump starts failing and only puts out 20psi, or maybe when the msd (or other highfire box) craps out during a nitrous pass.

Forged pistons arent indestructable by any means, but they are a hell of a lot more forgiving than the KBs.

 

Cross your fingers then. Most people crack ring lands using 150 shot on stock pistons eventually.
KB pistons are more brittle. i would go forged for sure over KB if using spray.

 

Eventually i'm sure-
but thats a long time. My friend with 120+k miles is spraying 150- untuned over and over and over again. Probobly 10 bottles now, or about 70 shots.

Keith blacks are stronger aren't they?

With that said- any non forged pison is gonna gernade your engine when it detonates.

 

yep, 150 shots on stock pistons are fine, just need da fuel

 

Some people get lucky for awhile, some don't. Always have money ready for a rebuild when spraying a 150 shot on stock pistons. I personally know 5 people who rebuilt motors when spraying...Some lasted longer than others, but they all broke the ring lands eventually.

KB's are stronger, but more brittle also. Meaning less forgiving when detonation occurs.

I used KB on a 383 I built, and they were ok I guess. Any time anyone is spraying or Forced induction, I recommend forged pistons. It is the only way to go IMHO.