Quote:
Originally Posted by Pushit2.0
Here is the damage. It looks to me like some casting lines on the water jacket side of the #2 cylinder wall caused the crack. The cylinder wall measures about .175-.195". So with the 5" of un supported cylinder wall they were moving all over and the casting line made the cylinder wall a little thinner and had stress risers, thus the crack.
It looks like the #3 and #4 were doing the same thing. The pistons have cracks where the piston skirt blend into the wrist pin boss. The Rod bearings have seen better days, but they were standard Kings, I will be running ACL race series with a special coating with the new motor. The main bearings look great, and the oil pump/front cover is junk after 300miles.
It looks like I am getting air in the oil, so I will be doing some oil control around the crank and oil pan, and I will port the oil pressure releaf hole a little more.
Now I have the parts needed to put the hard block in, then I need to make a parts list then start machining.
~John |
Awesome carnage.
With the oil pump/front cover being trashed after 300 miles, is there a harmonic balance issue similar to what we were running into with the 6g72? Was something out of balance? (clutch? balancer?)
If memory serves correct you were revving to just shy of 10,000 rpm?
The air in the oil would make sense with that high of rpm and the oil pan design. More baffles and perhaps knife edging the crank will help keep the oil down and not being thrown around. Have you thought about trying to run a deeper oil pan and modifying the pickup? Get the oil away from that flailing crank may help with windage issues.
Do you have any pictures of the rod bearings? I am wondering if they were wiped out from oil contamination/air in the oil or if it was an rpm/moving part issue. However, like you mentioned, the Kings are a great standard duty (but “soft” bearing), the tri-coated ACL race series (the black ones) are a much better option for the severity you are putting that 4g63 through.
Are you planning to do a partial hard block now?
"Stay in it"
