Budman II

iTrader: (1)

Mike, you cannot feel any roughness if you run your finger across them. If I had not torn the engine apart for the cam issue, it's possible it could have gone on running just fine with them like this, and I might not have ever known anything was wrong. I just want to make sure don't have bigger issues that might come back to bite me with the new build.

Budman II

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EZ, I did have an issue with a secondary float going bad and filling up with fuel, which dumped a bunch of raw fuel down the engine. This happened while we were out on the water, so I did have to run it for a bit after I replaced the float (I always carry a bunch of spare parts just in case). You may have hit on something here. I was tuned a bit rich the whole time it was running, but not enough to make your eyes water or anything.

Starting to think I had a combination of factors at work here. I guess I'll just have to triple check everything when it goes back together. Debating whether to go back with a 30 lb bypass on the block, or just plug the bypass completely to force all the oil through the filter.

mike tkach

iTrader: (3)

maybe ez is pointing in the right direction,all that fuel in the oil could be a big part of the total problem.maybe eddie young will chime in,im sure he has seen it all,or dean gellner[mr horsepower].

protechcoat

Budman , looks to me that possably to tight of oil clearence,cold oil issue ,dirty assembly,if the oil was thined out from the fuel in the oil.I beleve your right that if it wasnt for the cam going bad you would probably never know aboyt the bearings . They dont look bad enought to see metel in the filter. I was wanting to know are you running a oil thermostant ? I think if you look at your pistons that are scuffed you will find it will be the same ones that had the bad cam lobes .The oil splashing on the cylinder walls.

FIXX

iTrader: (2)

i have starter buttons,,crank the engine first then throw the ignitions..
have your machinest check the at several points on the journal's,i bet their off a bit,also eagle is known for not polishing their cranks to the proper R/A.....i have seen bearing completely come apart on the dyno because of this..

Rookie

iTrader: (4)

I am not an expert but the wear patterns look as though the journals were not concentric and loading the journals tight on the top and bottom. Like the caps were decked but never rehoned/bored. Also I would not use an Eagle crank. Saw a few stroker engines built with Eagle cranks that kept taking the bearings out. Problem was solved by installing a Callies. This was 10 years ago in 540's that had 700+TQ but that was enough for me.

Full Force

iTrader: (5)

I think I would look at tolerances and oil pressure, this is also a case where coated bearings help as I stated in other thread....

I mic all my stuff before assembly just to double check my machinists work, write it all on a sheet, I know everything about my engines in and out... if you assemble yourself its easy to log it all..

I had too low of oil preussure on my first rebuild (didnt know BBC then as well) and was wiping bearings out... people said oh 50 psi is fine... well it wasnt, I was told it was lines, fram filters, fittings and all that... guess what... it needed more pressure, Mercs lines been on the boat for 20 years and no way was that my issue... but people said to redo system... would have cost lots of money if I did for no reason...50 psi can be fine in some cases, its also about flow and volume... in my case was not fine..A Merc 1075 runs around 55, but the flow is insane..

I run 78 psi oil pressure with HV pumps, not had one issue since...

also make sure things are clearanced right, balanced right, alighn honed, and all that... then be careful and clean assembling, you will be fine...

Budman II

iTrader: (1)

Engine has oil pressure switch that will not allow fuel pump to energize until oil pressure is established. This effectively does the same thing. I could also do this by pulling the lanyard if I didn't already have the switch.

Budman II

iTrader: (1)

I sent a message to Clevite's tech department with a link to this thread to get their take on what the bearings look like. Here is my message to them and the reply back:

Original Inquiry:
I was looking at the pictures on the bearing failure analysis guide, and I am having trouble discerning whether the damage to my bearings in my BBC was due to contaminants going through the bearinngs or oil starvation. I did have 5 roller cam exhaust lobes that had severe spalling, and excessive wear on my distributor drive gear, so some junk did go through the engine. Pictures of the bearings can be seen on the following site: http://www.offshoreonly.com/forums/g...ml#post3842744 This was on a 454 Chevy running an Eagle 4.25" stroker cast steel crank, with Clevite P-series bearings. The engine has about 30 hours run time on it. I was running .0025 clearnace on the rods and .003 on the mains. Oil used was 20W50 conventional oil. I would appreciate an expert opinion on this. Thanks!

Reply Chain:

Posted 1/7/2013 8:32:35 AM by [email protected]
From your pictures, it appears that the bearings are suffering from a bit of oil starvation. When the bearing surface appears to be polished and shiny that is the most common cause.Recommended clearance for you Big Block would be: about .0027" on the rods and and about .0032" on the mains.I'm presuming it was in a boat. If so, oil temps in marine applications tend to be quite low, making the oil thicker that in a car running a higher temp. That makes it difficult to flow oil through the bearings, especially with a 20W50. I suspect that is why you see the polishing. Solution: open the clearance up or run a lighter weight oil. Also, it appears in the pictures that you might be getting edge loading/fillet ride on the rod bearings because they are shiny on the outer edges.I recommend the narrower HN series rod bearings when you re-assemble the engine!

I also spoke with Bob M about it this morning. Bob was in agreement that I had some minor oil starvation occurring. We both came to the conclusion that my issue very likely stemmed from the fuel diluting the oil and causing some oil surface boundary breakdown. If I had chronic oil starvation issues from the get-go, after 30+ hours it would have shown some blueing on the bearings from excessive heat, and I probably would have seen some elevated oil temps. Since I had neither, it was probably a relatively isolated incident. Had the cam spalling not occurred, after changing oil I may have just gone on running the boat for quite some time without ever realizing that my bearings had been "burnished" like this.

Nonetheless, I am going to double check all clearances carefull on re-assembly, and on Clevite's recommendation I am going back with the H-series bearings. Thanks for all the help, guys, and thanks especially to Bob M. for all his advice in helping me out with this analysis. Bob spent at least 20 minutes on the phone discussing this with me while obviously suffering the ill effects of a bout with the flu. Hope you feel better soon, Bob - you are THE MAN!

ezstriper

If you got that fuel down in it thats your culprit...I did one is so fast could not believe it...except cost me a new eagle crank and 2 rods !!! gas kills the oil so quick....