keith black hypereutectic pistons

[dadawg]

is anyone running these pistons and if so how do you like them.
the seem a nice compromise between conventional cast pistons and forged.

[Admiral Akbar]

I'm thinking about using the 10.5 domed pistons in a bagger build.. Max

[HIPPO]

I'm happy with them in my bike.

They have been in there a loooooong time, they came direct from Panman.

[Admiral Akbar]

I miss Ron.. He had a personality like a piece of 80 grit sand paper..  Max

[Billy]

Well I hope their QC has got better since the last few sets I've had my hands on. The compression heights have been anywhere between .010" & .024" short.

Buyer Beware.

[metaliser]

The piston skirts collapsed on my first try, had to tear it down and replace with another set, so far so good, this is not the only time I heard of this, I was at a Christmas supper last night and was talking to a engine builder for race cars and regular vech also and he put a set in a truck motor  for a farmer and after 500 miles it started knocking, he started out with 1 1/2 thous clearence and he rechecked the clearence and some had as much as 7 thous he told me  , he called KB up and they would not help at all, he said his little experience costed him about a $1000.

[taz95dog]

morning , my chev (5.7 vortec) has them,no trouble . but my tech said beware of detonation, that will damage these pistons faster than cast pistons . any truth to this?...taz...

[02FYRFTR]

Well I hope their QC has got better since the last few sets I've had my hands on. The compression heights have been anywhere between .010" & .024" short.

Buyer Beware.

Installed a set of 3.875" +.030" flat tops in my RK last month.  deck heigth was .000".  last set of  J E I used were -.007".  KB was very understanding when I told them them the oil control ring support rails were missing.  Sent me a new set at no charge within three days.  Must be sure you follow the ring gapping instructions.  My shop bored cylinders for .001"  clearance plus .0005" minus .000".  Built three in the last year with out an issue and all are running well.  I prefer coating the skirs however if they are not already coated from  KB.

[aquaman]

I'm running the 95" KB348 flat tops in mine and it runs great.

[HarleyCharley]

Got over 6K on KB348's with no problems. 

[Colorabee]

They are kind of a pain to install.  The bottom ring set protrudes down low enough on the piston skirt that it interferes with the wristpin hole, so you have to install the rings after you install the piston on the rod.  The spring stile wristpin keeper clip is a bitch to put on.  I had a hard time getting confirmation on the dome volume for their Hi comp piston.  I tried to use them with stock heads, a .030 gasket and TW6 cams.  I ended up with way too much compression.  But a cam change to SE 251 and DTT tc88 ignition, and I’m good.

[SuperAhcmed]

Too many issues Ive seen, not very durable, brittle with builds with less than stellar a/f and ignition tuning. I guess I can see people running them though on low power mild builds with stock range compression, but I'd never recommend them.

[HIPPO]

I miss Ron.. He had a personality like a piece of 80 grit sand paper..  Max

I always smiled when I read discussions he took part in.





When I used them they were still made in the US.

I did often recommend to people building their first Harley to use the Harley pistons. They are for all practical purposes almost a hyper and I used them a lot on customer bikes.

The KB's definitely require more care and experience to work with, but that is almost always the case with item's that have high performance features.

[fxstdavew]

I remember panman saying to watch out for quality issues about the same time he left KB they were making changes to his design that he said would cause issues ,allthough I doubt it was to this extent.I also like reading his posts. He would call as as it was.

[Don D]

I talked to him a while back and he told me that the pistons went to Mexico and then were pulled back to Carson City (Moundhouse)
Since they went to the spacer rings (a mark in time only not saying anything wrong with that) I have heard of a few with QC issues such as odd deck height. Last set I used was +.003 and +.004 and I have heard of several others either positive or badly negative. Not enough data to call a problem however. Doing a build over the holiday will see how these turn out.

[Hillside Motorcycle]

morning , my chev (5.7 vortec) has them,no trouble . but my tech said beware of detonation, that will damage these pistons faster than cast pistons . any truth to this?...taz...

We have witnessed that.
We won't use 'em.