Does anybody have experience with spraying a motor with these pistons? More specifically, they are the -18cc reverse dome .030 over ones that come in the Jegs/Eagle 383 stroker kit.

From what I've been told elsewhere, they are just a little better than stock LT1 pistons and people have sprayed over 200hp on those before.

 

be carefull they don't like any detonation at all.

 

I saw some thing where Keith black was claiming that their Hyp pistons are as good as a lot of forged pistons, but if they are anything like GM hyp's i would be careful.

From everything I have read, hyp pistons contain brittle spots which like to crack/break under stress.

Good luck.

 

I ran the KB flat tops in my 1st gen with a NOS Big Shot plate system... I used 250hp to 300hp jetting, and never had a wink of problems with them - had the timing retard not work and got some bad detonation for a second, and they still looked as good as new. If I remember right, Hot Rod/Summit Racing did a 800hp SBC (nitrous) build up with KB pistons ~10 years ago...

 

I wasnt so lucky with my stock hypercraptics

http://images.cardomain.com/member_i...23_13_full.jpg

http://images.cardomain.com/member_i...23_14_full.jpg

 

Those are the stock pistons, not KBs, correct? What happened? Lean out? Too much timing? They didn't get that way for no reason...

 

I can't make out the pictures too well, I am acessing the 'net through a TV monitor. But it looks like more than just detonation, especially the backside of the piston. Parts have a certain yield strenth and if you exceed it, they will break. This may occur even n an engine operating without detonation.

I don't knw if KB HE pitons are any stronger than stockers. Yeah, their ad copy says they're strong. Doesn't make it true. OTOH, Eddie reports good experience with them.

My bottom line is that HE pistons are great for OEM and OEM replacement use. Light, can be installed with tight clearance, etc. But if you have the motor out and taken part and are going to be sprayig/boosting it, I wouldn't use them.

Rich Krause

 

I agree, but when you buy an engine that already has them installed, why not use them til the break? I think that's what I'm gonna do

ThankSS for the replies folks! Now to decide what cam to go with...

 

Agree, go ahead and use 'em! A piston(s) getting trashed shouldn't take the rest of the motor with it.

Rich Krause

 

Thats always an option .....Just have plan B ready .

 

Yep, it's a stock piston - motor went lean on spray- Nothing to say the same thing wouldnt have happen to a forged piston though in the same circumstance, since they are sure not indestructable...

 

I sprayed mine with 175hp+ (.076 jet thru a shark nozzle) countless times. Sprayed it once with on two stages, 1st hit it with 150hp & the 2nd with another 125hp....lets just say it didn't make a full pass but the pistons lived. The motor has now grenaded with 4 busted pistons,4 bent rods, 2 cracked cylinder walls & a few screwed up combustion chambers LOL but even a good forged piston would not have survived my ordeal (long story). So I guess I would say I like KB pistons for the money because I sure gave mine hell & they lived longer than I expected. Like said before, they don't like detonation & get the ring gaps right.

 

I have always heard good things about KB pistone. they make there Ring lands wider to take more load then a Stock piston. I blew three stock pistons apart back in 99.

Still like most here I do not like using a Hyper. piston where a forged piston should be used

 

ok my family owns a performance machine shop and we build motors for alot of the big guys in top fuel dragster. (we also have our own)&most circle track and sportsman drag cars come to us also. but this is why i am posting its a funny story. this guy kept calling with all kind of problems he said he bought a jasper rebuilt 350 ci (ok for your daily driver but thats all) he said he was getting excessive blow by and he did not know why. well after spending all summer on the phone with him he finally brang in the motor. wanted us to tear apart and put new rings in. well we took it apart and the kb's were all melted and distorted. the walls were scored and the pistons had big black deposits on them when we called him to find out what he did since the motor only had 3,000 miles on it he finally told us he put a procharger on top well see thats your problem and he got so mad when we told him the pistons were junk and he needed a bore and hone,new rings and pistons. he then told us to order him some new 40 over kb's. well we told him to come pick up his motor because we dont build motors that we know wont last p.s.s hypernutetic pistons are just budget replacment's and anything other than stock should use a good forged piston

 

I agree!