i ran them in all my na race motors but there's crucial setup required. ring end gap must be right on a couple thousandths less end gap and the ring can butt causing broken piston. also these pistons don't like detionation. don't take but a couple seconds of hard detonation to blow the piston top.

 

Will they be ok for a mild street engine or are there still risks? I mean, All I am doing is a few bolt-ons and its a non-turbo engine...so its not gunna be reaking of power lol...but seriously, are there better pistons for my application?

 

again, i guess u don't understand me. i used them in my race engines. these are 4cyl motors putting out 200-250hp non turbo turning 7-8300 rpm and compression ratios in the 12-14:1 range ( i built a lot of different race motors so i gave the range for many of them depending on track rules, engine type ford gm chrysler, import).

if u want a way better piston, then u need to go with wiseco, je, ross, mahle, or some other forged piston.

i picked kb hyper pistons because they were really light, really low cost and worked great for my racing applicatiion. i have failed a few over the years. partially based on my encounters with what i exactly told u the causes of failure

 

Of course the ultimate is to have forged pistons....I like JEs. I put KBs in my Daytona and ran anywhere from 12-16psi on pump gas and they finally gave up 5 years later when I sold the motor to my friend and he ran it for a while then decided to mess with the boost control lines till he said it was peging the VDO at 25psi. Really it was probably seeing about 28psi or so this was all on a 2 bar map MP computer.....it saw its fair share of 25psi and detonation for about a month till he called me and I had him put a stock computer in and hook up the boost control lines right. It ran that way for about 2 more months till number 3 burnt and broke the ring land out of it. The damage had already been done two months before.

Yes KB pistons can handle some abuse that is only if they are installed right. When you bore the block have your machinist bore it to the exact spec KB says and make sure your rings are gaped to there spec and they will live for a long time. If you bore it to loose and give them to much room to rock they will not last at all because hypereutectic do not grow like forged or cast pistons do and they will beat there selfs to death with even the slightest detonation if they are to loose. We are putting them back in that same motor later this summer when we put it back together. They all come weight matched with spirolocks, drilled oil holes, machined domes and all.

 

I am running keith black pistons in my 69 440 6 pack charger! They are awesome so far no complaints! We had the machine shop assemble the short block so its all correct and the car runs FREAKING SWEET!
Good luck hope this helps a lil!
The pistons came quick and were of great quality upon inspection before installation

 

keith black pistons are whats known as hyperreutectic alloy. ( i didnt spell that right) they are basically about the same as a stock cast piston, except they are a bit lighter, and the manufacturing process allows the company to make the pistons with less wasted material. durability wise, they arent any more resistant to detonation than a cast piston, prolly worse to tell you the truth. and when they let go they totally let go like allmotor said. they have a tendency to shatter under hard detonation versus just cracking.
if youre just putting together a mild N/A motor dont waste your money, just buy some cast pistons from a good manufacturer and you'll be fine.

 

Thank you for understanding what answer I was lookin for, thanks to all for info too

 

Just get a set of stock turbo pistons; they're better than any hypereutectic piston on the market.

 

u know this because u are an arm chair mechanic or have you actually use them ( i highly doubt)

 

Thats the only piston we use in our big block race motors. They hold up very well in them. But we also dont use any type of forced induction

 

I've cooked 'em in turbo & N/A motors.
^ I know it's an N/A motor. I figured since he was looking at pistons & asking performance questions in other threads, he wanted something better than what carb cars came with. So, I recommended what I believe to be a good, cost-effective piston.

 

Here are a couple. Lasted five thousand miles at 23lbs. Judge for yourself.

 

Your failure is exactly due to ring gaps too tight! Do you remember what you set them at?

 

I have a set of 2.2 Keith Black pistons I got from a member here a couple of years ago. I didn't use them, and neither did he (he got them from some one but never used them). The original user ran 22 psi, made good power and they lasted, but he also followed the clearance requirements and they held just fine. I they are for sale (really cheap) if anyone is interested. You may need new rings.

 

TRW and Diamond make some nice inexpensive pistons for our engines too.

 

if you wana get silly with a N/A motor, id get some pistons made, forged, go with 13.5:1 comp ratio,H-beam rods, copper head gasket,studs everywhere, big cam, custom manifold that will hold a pair of either weber or mikuni carbs( one barrel per cylinder) fill it up with the highest octane race gas you can find and give 'er hell.

 

puppet, what do trw's or diamonds run? i am assuming you mean forged from both, afaik, diamond only makes forged. i havent found a set for under 4 bills but i just started looking today.

 

hypeurtectic pistons are lowest on the totem pole. To me they are absolute junk,they are good for the kb company because they can be produced at low cost.But in a turbo motor? no freaking way

 

Well, hyper-eutectic pistons have their advantages--light weight, allows tight piston -> cylinder wall clearances, and low cost to name a few. They're pretty strong as long as you don't smack them with a hammer.

But if you want something more robust and more resilient to your accidental excessive ignition advance, boost spikes, and detonation or whatever, go with the Mahle piston for cost savings and forged if you want to beat the snot out of it. I wouldn't use them in this application. On a TBI engine, I definitely would.

I have a neighbor with a '69 Camaro that runs 11.6's in the 1/4 with Keith Black ~10:1 pistons. Its an all-out drag race car, so not a lot of actual miles on it. In 10 years, the engine has been apart once because of a valve float issue where the piston smacked the valve. The piston made silly of the valve.

 

i have personally called kb and spoke to them, and they do not recommend there 2.2 pistons for anything over 10 psi of boost.

 

Chrysler does not reccomend them in turbo engines

 

sigh... the good ol days

 

Donovan's garage has an article on them from Ed Peter's retired engineer.