KB Pistons?

[PhilaTruck]

Are KBs still good pistons?

Either these (left-right) or these (neutral)?

Thanks-

-Todd

[Ticker]

I personally prefer SRP/JE - the pro series with rings, etc. are good deals and the finish and precision is outstanding. That said, KB's are fine

The two pistons are very different - what's the application? What cc chamber?

[chevybuldr]

yea you need to provide some more info here. What are you looking to do with this. Either way you are going to have to run goooood gas. Being that you are looking at dome I am guess you are. I kinda prefer the forged line of KB they are nice. I like SRP forged line a little more. Its all about the budget. Just remember that those Hyper take a special ring gap on that top ring.

[1968SWBBigBlock]

Yes KB makes a good piston
I do have to agree with what has been said above.
Look at the FHR sieries of forged piston from KB

[cableguy0]

kb doesnt even make the pistons anymore. they are outsourced. keith black isnt passed away and his name was sold off and a lot of the pistons are foreign made. we found the pistons are really sensitive to going a tiny bit lean and pistons will come apart. they used to be tops but at this point i would go with something else like the je's

[shortbed70]

KB pistons are good but there hypers are a little heavy and I've heard you need to really pay attention to top ring gap on them. I have a set of dished hypers in mine and no problems here.

[1968SWBBigBlock]

Cableguy -= when did KB start outsourcing pistons?
When I bought mine 2 years ago they owned 2 plants - one in the USA that made premium forged pistons and another in mexico that they have been in for 20 years that makes the FHR forged piston, Hypers and clamiers

[cableguy0]

i believe it was somewhere in 08ish. i know there was a lot of issues with the hypers breaking or cracking. mulitple quality shops were having issues. the suppliers knew of the issue etc. we all but stopped using them and went to je pistons on most stuff. requiring a better piston than just a regular hyper.

[Ticker]

Virtually all pistons today are made to some extent outside of the US - ether the materials or the slugs, although usually final machining is done in the US.

The issue with breaking pistons came from KB's recommendation for an unusually wide top ring gap that a lot of machinists missed. The ring couldn't seat fully in the ring land because the gap closed, then would gall and finally catch, breaking off the top of the ring land and usually the crown of the piston.

Not saying KB didn't have quality control issues for a while, because they sure did (along with Sealed Power) but every situation I ran into was a "normal" top ring gap vs. what KB spec'd.

[chevybuldr]

Pretty much what Ticker said above. They are the same company the makes Silv-o-lite pistons. They use to be hyperutectics only. KB is just a product line. There claim to fame was a large distance between the first rind and second ring. That cause the second ring to run hotter. Most people were not reading the instructions and finding that it ran a larger rind gap because of this. Some almost as high as .035 gap. It was then that the top ring would blow the gland out of the top. If everything is set right they work good but they are still a cast style piston. Remember chevy was using hypers in there motors for 20 years if not more.

This tells you how hypers material make up
http://kb-silvolite.com/article.php?action=read&A_id=2

[PhilaTruck]

Sorry- I posted the dome. That was a mistake.

It's been a few years since I shopped pistons and I remembered comments like those above and wanted to check it out. I've got lots of cam and wanted to run up the CR a bit. (73.5 chamber on 4.155 x 3.75)

This will always be a NA motor, so I don't *need* all forged.

It runs now, but maybe I can get it to run a little better...

Anyway. Just doing some initial research. Thanks for the info.

-Todd