B engine3 rebuild problems.

I still think its a rod bearing issue but i have heard of the wrong depth of ring being sent for the piston suplied . a 350 kit came with shallow grove pistons and deep  grove rings once.

Edited by mlpankey - 01 Apr 2010 at 3:53pm

he said he had to pound the pistons thru the liners--- the liners are obviously out of round and the main problem. Besides that, they are bored oversize.

I would put one piston in at a time till problem occured, check to see if wrist pins contacting sleeves.  Crank reground? did they get journals true to center line? If not the rods get really side stressed.  Just a few thoughts. 

Nope, You didn't find your problem due to cracks. No way crack could cause it. If the sleeves are not out of round after they have been removed then the only thing that could cause that would be to drive them down into and out of round hole at the bottom.
As I have stated many times and in this thread that the sleeve need to be able to be placed in the block and turned 360 degrees by hand. Fitting sleeves new or old in a used block takes time and care. The extra time taken to the little details will save much heartache as well as time from do overs.  

I use an air die grinder but an electric drill will work as well. I use a sanding flapper and keep checking the fit as I work. I use wire wheels to remove the scale also.

Dick L wrote: Just for food for thought and maybe for conversation I looked up some stuff on piston cylinder wall clearance for Porsche and found this. [I just had my 95 bored to 98 and the spec sheet shows .0015 for the J&E pistons, so the cylinders are that much larger than the pistons, not .003, is that what your looking for?] One piston manufacture called for a clearance of .0008 in a Porsche engine. Yes a little less than one thousands. I had a machinery salesman in several years ago that quoted the clearances that was used in nascar. I can not remember what he quoted and have not found it yet on the internet. He has sold the CNC machines that were used to machine fit the heads to each already installed piston.

No dick this is what is was thinking of. I confused it with promod clearances which are not stated but are even more for the 1600 horse shot of nitrous or the 14-71 blowers.   http://www.jepistons.com/PDFs/TechCorner/SCPDrawings/piston_instrc2618.pdf

steve(ill) wrote: a rule of thumb use to be .001 inch clearance per inch of bore diameter... maybe not exact, but thats a pretty good place to start.

  Best thing to do is use the manufacture of a products sugestions for they know the materials compistition and how it expands and contracts to heat . I personally use J@e pistons but I used total seal rings . My bore gets what J@e wants for clearance my rings get gapped to what total seal recomends for ring gap. the promblem with kits is most the time you dont get the vendors recommendations for each piece.