Help!! Found Gold

Yeah, but he's saying the rods look ok, with the exception of the junk from the mains going through them.

So you'd think that if it spun the mains, it'd have hurt the rods too. If there was inadequent main clearances, it'd also have starved the rods.

I'm no expert by any means, but I'm thinking the crank is distorting, and causing it to crash into the bearings.

 

THANKS TO ALL,
I think it was the oil with the alc.
Found a new machinist
Help
Clearance on the mains and rods?

 

I like .0035-.0038 on the mains and .0025-.0028 on the rods w/50 weight oil, but that's with a BBC, not a SBC. Never messed with a SBC to know if the clearances are the same.

 

clearance SBC

I run SBC's. I would run .0032 on steel rods and .0032-.0035 on the mains with number 5 set at .0035-.004. You need a bowtie block or aftermarket block. Factory 400 blocks are weak in the mains. Mag the block and look for a crack from the main up to the cam galley it will be on the outside of the main where it meets the outer side of the wall and travel upward. I do not have an explanation for why but......the first main to crack is normally #4 this could be your problem. If the block is sound then it had to be a clearance problem when the engine was assembled. I agree use Brad Penn or the "true" Not for Highway Use racing Valvoline. It is also easy to have "too" much oil in an SBC, when this occurs the oil pressure will fluctuate as the car leaves the starting line, the oil wraps up in the crank and foams causing oil pressure issues. Normal oil pressure on a run will be the steady and rising as the car accelerates through the rpm range then drop slightly on the gear change. When RPM slows it climbing rate in high gear the pressure will start dropping slightly (5-8 psi) this is due to heat buildup in the oil from the bearing surfaces. When you go thru the lights you need to put the car in nuetral becouse you will not be able to keep oil pressure during decelaration so you do not want to load the motor. I am sorry for the long winded post just trying to be helpful. Have a good day.

 

I ran blown alky sbc for a long time ran green 20-50 kendal .0035 .004 clearance on rods .004 .0045 on mains had a titan pump 80 lbs pressure at idle 100 on the run. Had a 8 qt pan but ran 12 qt of oil ran a hi helix 14-71 with 40 lbs of boost @ 9200 rpm never had bearing problems.Make sure you have the oil restricted on the rear of the block you could be pumping your pan dry

 

i was talking about the REAL kendal oil its been 8 years since i ran a blower motor the old boxes still had big daddy's picture on them lol i would not run the new kendal