Bearing experts??

Any ideas what's going on here? Front to back. Lefty to right.. This is out of my 500" turbo motor . Stock 440 block stock caps. The mains look good except the thrust bearing. The thrust faces look pretty much untouched. The rear 4 rod bearings damage I would say probably from the junk that got pumped through it at the end. Just some scratching.

Not sure how many passes it has but it hasn't been apart some 2011. Been running 12-16ish psi

I would check the crank for run out to see on the all the main bearing surfaces to see if it is bent or not
I don't like to see any run out at all on any of the mains
EDITED, look real closely for cracks in the main webbing between the bottom of the block cylinder walls down into the main webbing also I'm not trying to alarm you but better to find it, any problems, now instead of running over the crankshaft later

Ok thanks Cab. This motors race days are done. I am building a new short block for the race car. This 500 will be going in my 63 for street duty. unless the block is cracked.. lol. Ill pull the crank and get it checked too

I'm not fluent in oil flow paths on a BBM but is there any way flow can be restricted to #3 main and the front rods progressively worse front to back without scorching #1 & 2 mains? If the crank was bent I would expect at least one of the other mains to be showing some signs of stress. That one rod bearing closest to the thrust looks like it was about to go knock knock come out.

Kevin

ya there was a ton of build up around the dowel. Luckily it didt spin. Crank still looks great! Or great enough for me .. lol

To me it looks like the clearance was tight. When I say clearance, we've found when the crank moves those particular bearings need to be looser. The number 3 main only feeds one (#4) of the "bad rod" bearings. Maybe some taper in the #1 rod journal as well. Are all the journals the same diameter and straight? all the rod bores the same and round. Are all the rods still straight? How much clearance did they have? That's what I would be checking. My sons turbo 360 cast crank pics on the #4 main. That main runs now slightly over.004". Our bet is the cast crank looks like a jump rope under boost.
Doug

What oiling system? How much pressure-volume? Driver side lifter galley blocked or lifters bushed? Reason, sometimes oil velocity is so much it goes by the down line to the mains if there’s big oil bleed off in the system. Those mains look oil starved

My best guess is you are starving it for oil on the launch.
Middle sump pan?
Oil climbs to the rear of the engine and splash oils the rear half of the rotating assy.
Are you logging oil pressure?

Yes center sump road race pan. Running 8 quarts. All the baffles are cut out. Has a single line Milodon pickup. Logs show 70-75 psi whole run.

Hmmm. Stumped.

I miss read your post

The reason I didn't mention starvation is that not all the bearings reflect that. Normally starvation shows up towards the rear bearings 1st. Not the case here.
Doug

Why is it apart? Were there symptoms? Im surprised the logs never showed a change.

Building a new short block. I was checking bearings after the beating this block has taken. This combo has been 138-140 mph in the 1/8th mile at 3550 pounds so it been making some power I was expecting main bearing damage but not much rod bearing issues. Was planning to throw a different cam and heads on it and roll some new bearing in it. Then run it in my street car.

I did notice some light bearing material in my K&P when I was creeping up on 18 psi. So I turned it down for the last race. Assuming it was main bearing material. That's the main reason I pulled caps. As for logs there was zero change in oil pressures throughout the year.

I think the #3 main bearing trash mostly went into #4 rod and some of that material may have been caught a tiny bit by #3 rod
I'm really surprised that none of the main bearing trash from the center main bearings wasn't wash into #5 rod bearing also
Did the motor have at least .0040 or more thrust clearances new?
Was #3 main bearing straight with no taper front to rear on the clearances?
I've seen between .0002 to .0004 taper on some of the new main bearings with block that had been align honed with new main caps and studs

I'm guessing you are starving for oil on deceleration. Maybe rethink your oil pan and pick up??

Whats your engine/turbo combo? Sounds like its making some decent steam for sure!

These are my questions. Why would the #3/4 rod and #3 main be hit the worst? Is the main web cracked? If there was lack of oil feed to the #3 main the #5 rod should show wear as well. #3/4 are not last in line for oil. What was the bearing clearance? Are the journals round and straight? Is the crank cracked?
Doug

Since there is contact all the way around the whole bearing...

1 Had this been happening under power and or at RPM. That rod would be through the block. This is a low RPM occurrence,

2 the effected areas could just have less oil due to the delivery or from possibly bleed off.

3 The effected areas could also have less clearance...

I run on some pretty long tracks. I wouldn't think that would be a issue. I am never on the brakes hard. I suppose its possible though

9.5-1 500" RB factory block. Mopar VI heads. EFI precision 114mm turbo.. It makes more power than the factory block can handle.. I was surprised the main bearings look so good.

Those are all questions that I don't have answers for yet. I haven't lifted the crank out yet. I don't recall the clearances but they were plasti gauged when I built it and within spec. Didn't check every journal but checked a few.. I swapped bearings out back in 12' when It ate a piston. They looked like new then.. Only change is the oil pan. Ive ran the same single line Milodon plate added to the Melling HV pump. Square Pick up is about 1/2" to 3/4" off the pan floor.

How deep is your pan(measured) that PU is a long way off the bottom

5.5" deep Shoot I'll go measure the pick up depth

Ya the pick up is just under 3/4" off the bottom. I cant go much lower do to the roundness of the bottom of the pan. Atleast not without mods. The sump measures 9" front to back and 13" wide. total pan depth from rail to bottom is 5.5". The sump is about 3" deep

Thats a long ways off the bottom.. I'd mod the pan so you can be no more than a 1/4"off.. you
could be sucking in air

on it..

Like DVW said, I'm interested to see if the crank passes the mag test.
The pickup needs to be a lot closer to the bottom of the pan.
Plastigage for checking clearances isn't even close. All it does is tell you if you have clearance or not, lol. Get a 2"-3" micrometer and a dial bore gauge.

Those Milodon sandwich plates aren't known for flowing real good. Not saying that's your issue, but I'd look into other options like using a Milodon cover on top of that HV pump.