Blown Alcohol hemi eating rod bearings

I am new to blown alcohol and this is a hobby kind of deal not a full blown race operation so please be easy on me. Some background the Car is a 65 plymouth belvedere with 7.5 cert. I have a 572 cu aluminum world block, Keith Black billet crankshaft, BME alluminum rods, diamond pistons, stage 5 heads, lsm .750 lift 292, 294 duration 116 lsa 65mm camshaft, littlefield hi helix 12-71 25% overdrive blower enderle big and ugly injector. Have made about 8 passes. I dont spin it above 7500 rpm. No need to the car only weights 2200 and i go plenty fast as it is. Anyway, I noticed aluminium in my oil filter and found that i had some valve cover and gear drive clearance issues. Got those fixed and was still finding junk in my oil filter. Decided to take the engine apart and found that it wasnt aluminum but that it was the rod bearings were toast. Mains were just fine. What can cause the rod bearings to go bad that quickly. i did make a mistake ( i wont say what it was) and made two passes and dumped alot of alcohol in my oil. The oil was really milky, like there was alcohol floating in it. I read that this can take out your bearings. I set rod bearing clearances at .0035. Are they to tight?? Any and all suggestions would be greatly appreciated as i really dont want to loose this motor due to a stupid mistake.
thanks in advance. Ken

 

Well my first guess is that some of that aluminum from alve covers could of done some of that. Was the oil hot when you started it. Was it new oil new. If it has alot of alcohol in the oil like from too much idling for your buddies , I have seen that happen . That clearance seems too tight for a hemi , brad will tell you they want .004 on mains and .0055 on rods. Maybe look there.

 

The oil wasnt hot when i started it. I am running brad penn 50 wt. It was new oil. The oil got watered down because i had two plug wires reversed ( i didnt want to admit that). I ran the oil another pass even after it was milky.

 

Both the upper and lower are bad although the uppers were alot worse than the lowers. the lowers were barely showing copper while the upppers in some cases were completely gone. I was using clevite H bearings. I cant remember the number but i will go look it up and get back to you. I am running Brad Penn 50 wt oil. The oil pressure starts out at 110 lbs and is at 50lbs by the end of the run.

 

How much oil

My opinion is that you don't have enough oil in the sump and it is holding the oil in the cylinder heads, it gets worse with hi volume pumps, we would run 12 minimum in a wet sump and 15 in dry sump.

 

bearings

You should use either V orM bearings the Vs are the best for blown applications.

 

My thought is the rod clearances are pretty tight - 50wt might take less clearance than 60wt, but I wouldn't set it up any tighter than .006 on the rod journals. Plus tune up issues maybe...
Make rod bearing inspections/pulling the pan part of your weekend maintenance ritual after 2-4 runs until things prove this is too frequent.
Search rod bearing on this site, there is a lot of previous discussion (great stuff) about rod bearing set up clearances and bearing types.

 

What bearing manufactures do most people run for 0.006" clearances? Joe

 

The bearings are std , .010 under etc. You need to have the journal ground to the right number--- not the other way around---- if it was me I would not run .006 on the rods in ANYTHING, if a Nitro combo doesn't need it why do you ? If I remember right the screw blower alky combo's run the rods tight ---------------- along with the mains too.

 

I agree with adjusting the journal portion of your post. If you ask nicely I might respectfully respond to the portion of your post we seem to disagree about (but probably not).

 

I find that when the rods are brand new, the bearings measure .006 clearance on the crank. After a few runs, the rods will collapse a little bit, and you will have .004 to .0045 clearance, which is about right.