opinions on kb hiper pistons ?

[jerry]

would K B hipper pistons around 10 1/2 to 1 be a good piston  for street use.? or would another brand be better? motor is a 69 six bbl  30 over.looking for opinions.

[Chryco Psycho]

I will not use Hyper pistons even in my lawnmower , Forged pistons only cost $200 more which is a Lot less than the cost if a hyper piston fails  & if you want to do more with the engine later on you do not have to rebuild again
I use the Speed Pro L2355F in most street 440 engines 

[tecmopar]

I agree with Chryco, the Hyperuf**ked pistons are good paper weights and thats about it, good luck.

[jerry]

I will not use Hyper pistons even in my lawnmower , Forged pistons only cost $200 more which is a Lot less than the cost if a hyper piston fails  & if you want to do more with the engine later on you do not have to rebuild again
I use the Speed Pro L2355F in most street 440 engines 

thanks for your reply.the cost of forged pistons didn't sway me.i have stock original i beieve cast pistos in the motor now and have had no trouble with them in 30 yrs.stay with me now for i know nothing about whats right in 2006 for a 440 motor.i don't even know if KB hyper and stock cast pistons are comparable. they were just something that was brought up when talking pistons for my rebuild. did i want quite motor or go with the forged.the speed pro were mention if i went forged. are KB hyper pistons a good piston if i went that route or are they junk and is there a better cast piston i should go with if i go that route. again thanks for the help.

[Chryco Psycho]

the factory cast pistons were good pistons But they had a steel liner in them , the Hyper piston has more silicon in them & have to be carefully fitted to live , they are also more brittle & can shatter , Like I said I will not use a hyper piston in my lawnmower , it just isn`t worht not using a good forged piston 

[TylerCharger69]

My experiences with Keith Black pistons has not been very good.  I put a set in a HiPo 289 Mustang  I built for a friend of mine.  I filed the top ring as required for heat expansion  (These particular pistons were 12:1 forged at .075 gap on the top ring.)  Well..long story short, the top of 2 of the pistons broke off, causing extensive damage.  I rebuilt the motor immediately with a Wiseco version of that same piston....well...no troubles at all and takes a beating!!!       That's just my experience though...car does mid-9 second passes!!!

[Runner]

ill be the goat here,  they are in my 452 and they will be in the 440 im biulding for my daughter.   but hey i beat the snot out of a set of cheap badger pistons in my last 383.

[Steve P.]

I am with Chryco.. Though I have a 40 over 440 with KB pop ups in it, I am very much on the fence. I bought the motor this way and all the machine work and balance work looks good. If I was building from scratch there is no doubt I would be using forged flat tops..

[chargerbr549]

In our machine shop we have built alot of motors with KB pistons and we really haven't had alot of problems with them as long as you follow their recommendations and try to keep the compression ratio from getting too high for their driving conditions and fuel quality they are going to use. With that being said, personally I probably wouldn't use hyperuetectic KB pistons or any other brand for that matter, as some of you have said already that they are a brittle piston and they don't have much forgiveness when push comes to shove, the only real advantage to them are they are generally less expensive and you can run a tighter clearance, which can help on oil control and noise. I probably would only use them in a street application and maybe some spirited driving but if your building a serious street/strip or strip motor, Forged Pistons are the only way to go, they take way more abuse and if they fail they generally will keep your motor in one piece whereas  a shattered cast piston generally lets the wrist pin and connecting bang all over the place and its usually not a pretty picture. Just my two cents worth.

Kevin

[Chryco Psycho]

I would use a Badger piston over a Hyper , badgers were not bad for $200  BUT personally it is forged or nothing in anyhting I build

[Runner]

well, id much rather run a kb than a badger piston. i dont think a kb is the best piston out there  but imo its a decent budget piston when set up correctly. i hashed out these same conceerns thats listed here when i was biulding my motor and he told me that as long as we play with in the limits of the piston we would be fine. there are alot of people running them with good results however like anything you have to know there limitations.

      now if the engines a 383 and you want to run any kind of real cam youll be stepping up to a custom piston or getting those heavy trw or speedpro forged pistons fly cut. so add that into the cost.   in my case i biult a short rod 452 (400 stroker) and the only pistons i found for that biuld was a ross and the kb,s .