AIR FLOW PISTON

[Mike67]

As a follow up, if you will, I did not find the metal piece in the other head or intake but did find another plug with collapsed electrode. Is there anywhere that you suggest I look? Thanks again.

Look in your exhaust for the missing piece, header /collector/ manifold.
Definitley need to check your piston to valve clearance before reassmbling. KB recommmends .040". May need a thicker gasket.

 

[Ron Keefer]

Like Doug, I never broke the top of a KB. I have a 12.08 second 413 Dart with them. It was built to race several years ago, it only gets street use these days. I also would not risk further damage by running that engine, there is a reason why you have a second plug with the gap closed.

 

[Gunner1]

I built a lot of chevy and ford small blocks with KB's. BUT i used file fit zero gap top or second rings opened up to KB spec. Worked fine. But forged was always my first choice. Customers can have final say though.

 

[Boone]

Like Doug, I never broke the top of a KB. I have a 12.08 second 413 Dart with them. It was built to race several years ago, it only gets street use these days. I also would not risk further damage by running that engine, there is a reason why you have a second plug with the gap closed.

Thanks. Given my record with this car and the advice, I did leave it in SC. Plan to trailer it back to TN in a couple of weeks. Currently planning on replacing only the one piston provided the rest look good. I'm sure there is prep work when changing individual pistons and somewhere in that is a BEP vs going with a set. I do appreciate your input.

 

[Boone]

I built a lot of chevy and ford small blocks with KB's. BUT i used file fit zero gap top or second rings opened up to KB spec. Worked fine. But forged was always my first choice. Customers can have final say though.

Thanks for your reply. While I have built a few BB, this is the first truly hi-po and it is a learning process. Had not planned on that but I'm just lucky that way.

 

[Boone]

As a follow-up on the piston break, most of you were correct on the piston type. I reviewed the spec and end gap should have been .028. I was surprised that #6, the broken piston was gapped at .021. Doesn't seem a big enough difference in the two. Cylinders 4,6, & 8 are scarred; going to .040 over. Still haven't decided what type piston to go back with. Not leaning toward KB.
For what it's worth. Thanks for the assistance.

 

[steve340]

I have found the KB pistons perfectly OK in a mild performance/street engine.
I am surprised how many people do not know they need extra ring gap - once you screw it up "read the supplied instructions" I guess.
I have fitted a few sets over the years and found they run quiet and have low to none oil consumption with that extra ring gap.
I always use running in oil until the engine has done 800-1000 street miles.

 

[1 Wild R/T]

I have found the KB pistons perfectly OK in a mild performance/street engine.
I am surprised how many people do not know they need extra ring gap - once you screw it up "read the supplied instructions" I guess.
I have fitted a few sets over the years and found they run quiet and have low to none oil consumption with that extra ring gap.
I always use running in oil until the engine has done 800-1000 street miles.

Yup, Okay for mild performance stuff, just don't use boost or nitrous and don't crank in to much timing, they react poorly to detonation... Detonation is never good but causes less problems with forged pistons..

 

[3sloppydogs]

Now here is a piston

 

[1 Wild R/T]

Now here is a piston

View attachment 1242897 View attachment 1242898 View attachment 1242899

Thats just a baby.... I worked on much bigger stuff when I was in the Navy..... Similar to this....

 

[3sloppydogs]

I wasn't in the fleet
We seabees didn't see stuff that big

 

[1 Wild R/T]

I did a stint with ACB-1, nothing big there... Then a stint at SRF Guam.. SRF = Ship Repair Facility... Lotta big stuff there... Then a stint on a Gator Freighter... And finally it was time to go home...LOL..