UBETRUN

Took a 496 solid roller to the engine dyno today and left with a pile of wiped bearings. Not sure what happened, hoping some of the motor builders can make an educated guess.

The motor was built by a guy in Arkansas (that supposedly knows what he's doing) for use with a blower in a boat. The boat owner ran out of money before the motor was finished and I bought it cheap. Mid-70s 2 bolt main block converted to 4 bolt mains with 4340 caps, forged ams (?) stroker crank, forged eagle H-beam rods, forged JE pistons, mild solid roller cam, sharps roller rockers, ported chevy rectangle port heads, SS valves, edelbrock C454 dual plane intake, MSD billet pro, and Holley 1150 dominator carb.

Primed the motor through the distributor hole, used Rotella 30w oil, WIX oil filter, and warmed it up before making a pull. After an initial 10 minute warmup, we changed the oil and filter. Cut apart the filter and did not see an excessive amount of debris so we went ahead and made a pull. Motor showed 45psi oil pressure at idle and we only made the one pull to 6500 rpm. Had a small oil leak at the front of the oil pan under the timing cover so we pulled the oil pan to fix it and checked the front main bearing out of curiosity. After checking the first bearing, cried a little bit and checked the rest, they are all wiped. Crank looks like it can be polished, no gouges. Without knowing exactly what caused this to happen, I'm nervous to just clean it up, install new bearings, and try again.

Thoughts?

whitehause

I'm not an engine building expert, but I've done a couple. It looks to me like the wrong size bearings were installed. Do you have a history on the crank? Was it stock size, or cut down? If it was stock and they used oversize bearings,or cut 10 and they used 20 or 30 bearings you might expect to see this kind of wiping after only a couple runs. That's the only thing I can think of that would wipe the bearings that quick. I'm sure there may be other reasons I'm not aware of, but I would check the crank dimensions and look on the back of the bearing to see what the size they are. I know high oil pressure is a good thing but 45psi on a warm engine at idle seems a little high. That could also be caused by tight bearings. I'd say clean up the crank, mic and plastigage the crank and bearings,and give it another go.

427Hotrod

First...sorry to hear of the troubles...that has to hurt!

Any idea what clearances were?

What oil pan? Pump? Pickup? How close was pickup to pan? How much oil in the pan?

There looks like it has some trash run through it..but hard to tell with the other bearing damage. Hard to tell what happened first.

What balancer is on it?

Which bearings are toast and which look better?

JIM

UBETRUN

Crank is stock sized, we measured it, and the bearings were x1 (-.001). The guy that owns the engine dyno also builds race motors and wasn't concerned with the bearing size, he said a little extra clearance is a good thing on a performance motor but that doesn't quite jive with the high oil pressure...

Oil pan is Milodon 7qt and the pickup was definetely extended but we didn't measure clearance from pickup to pan. We put 7qt in the pan. Oil pressure never fluctuated so I'm hesitant to think it ran out of oil, wouldn't that show up as fluctuations on the oil pressure gauge? Or do those bearings say lack of oil in addition to the debris?

We think it was trash in the bottom end or oil passages. They had to grind down the corners on the front main cap to fit the oil pan and my suspicion is that they clearanced the front main cap with grinder after the bottom end was assembled. When I mentioned the clearanced front main cap as a possible source of the problem, the guy that sold me the motor offered a full refund. Since I'm in the motor pretty cheap, I'll just keep it and cross him off my Xmas card list.

Balancer is ATI.

ALL bearings are toast, every rod and main bearings look exactly like the pictures above. No difference front to rear, they are all equally trashed.

I'll call the dyno/shop owner on Monday and ask him about the bearing sizes again. I'm pretty sure he said x1 for .001 undersize but I'll doublecheck.

BLOCKMAN

With out having the oil filter bypass plugged its hard to filter the oil when its cold, The bearings surely look like debris went through them.

We see alot of circle track engines back for refreashens and we never see anything like this, We have a Callies crank that was bought in 1989 and still looks like it came out of the box.

Your using a nice filter but not filtering a 100% of the oil will push debris through to the bearings.

jackson

what he said is right. Sometimes you get a NEW crank with journals that're actually normal / a bit larger than normal ... hence X1 ... exact opposite of what you do with a worn journal.

you say it's a 2bolt converted to 4 bolt ... are you certain the retro caps were properly aligned-honed?
Are you certain the crank is straight?
Are you certain journals did not need even More extra clearance than X1 provided?

I like rotella, you say yours had it too ... good oil.

But I'm baffled; maybe a bit bemused ... because we haven't heard from some of a core group of about half a dozen self-appointed oil-test gurus who've been adamant rotella naysayers ... I'd expect them to be piling-on here to claim your problems could've been avoided if you'd tripled your oil budget w/ synthetics from regency violet, amdirt, movable etc.
Lemme be clear: your choice of oil did Not cause or hasten your failure.

whitehause

I use Rotella also, and have had no issues at all. Besides that, I'm not sure there is anyone that recommends synthetic for break in. Most say it's too slick to allow proper "wear in" of new parts. Even with some trash in the galleries, I can't imagine it would fry every single bearing like that. It almost has to be a size, or alignment of the crank issue.

midyearvette

if indeed it was a new build and you did not inspect or tear it down before you ran it, all you can do from here is purely speculate what happened.....my guess is it was built dirty and without a plugged by pass, some crap was run through the oil system...tear it apart and polish the crank and check carefully all the oil passages for dirt and replace the pump....start over and be glad you found this out now...jmo....

BLOCKMAN

We use to use a lot of the rotella-t 15/40 til it went down from 1400 PPM zinc to 855 PPM zinc a sit not a recomneded oil for flat tappet engines any more.

Here is a link to look over
http://www.bobistheoilguy.com/forums...35#Post1415835

whitehause

I've heard this before, but a Shell rep. said that it is still at 1200ppm.

Dear Sir,

Rotella T does meet both API CJ-4 and API SM requirements and still has ~ 1200 ppm ZDDP . The reduction in ZDDP requirement is not an API specification, but an ILSAC GF 4 requirement.

Regards,

Shell Technical

This is of Dec 2009.

427Hotrod

Definitely not a *brand of oil* issue..or even a weight issue. It has clearance and/or trash problems.

Time to take it completely apart to the bare block. You will need to clean every passage in it...remove all the plugs. Take pistons apart, heads apart etc. There is debris everywhere that needs to get out.

Then re-measure main bores and determine clearances. Extra clearance doesn't hurt things like that. Something is off in the clearances I think.

Plan on turning crank I would think to .010. Hard to polish extra clearance into one.

Plug filter bypass.

JIM

MotorHead

Not oil brand problem but an oiling problem. Don't know what to say other than something was seriously wrong with the motor for that much damage on break in on a dyno.

Mickey mouse build with either oil starvation or crap going through or clearance not in spec or all of the above.

I certainly hope you can save the crank etc. And get it rebuilt properly for not too much coin

UBETRUN

I kept picking at the front main cap being clearanced with a grinder to fit the oil pan and sure as ****, the 25 year old son of the builder admitted to using a grinder on the front main cap *while it was installed*!!! Not one but two idiots in that shop, the one that used a grinder on an assembled motor and the one that didn't supervise.

Total disassembly and cleaning is in order before taking another step. We will certainly pay close attention to the crank diameter and I have faith in the guy with the dyno that's helping me, I never saw a stack of billet blocks before visiting his shop on Saturday!

This motor just went from being a smoking deal to being a question mark. If I can get through this without replacing anything major, it could still end up a good deal.

Thanks for the tech assist guys, I'll let you know how it all turns out.

MotorHead

Not really the correct way to clearance the front cap but they could have at least taped it off and completely sealed the bottom end and nothing would have gotten in.

If someone took a grinder to the front cap without covering anything up then better take the motor down and check everything, no one that stupid should be near a motor and god only knows what else it wrong

TheSkunkWorks

This kind of thing is why I started doing all of my own assembly ages ago, having adopted a strict go / no-go approach rather than possibly accepting someone else's Bubba/ballpark one.

To that end, while you have it torn down I'd inspect absolutely everything, resisting the urge to skip any corrective work which may be indicated, even if that means a comprehensive re-machining.

Anyway, as for the crank I'd try having it micro-polished first (I'm not talking about you doing the shoe string and 400 grit method here), as turning it 0.010" would certainly remove a tuftridded/nitrided hardened surface, if present. We* were able to so remove a number of slight scratches/scuffs on my L88 crank, achieving a beautiful mirror finish without necessitating non-std bearings.





* ...the guys at Dynotech Race Engines, actually

427Hotrod

I agree....IF it will clean up...maybe that's just bearing stuff stuck to it...then polishing is good. I was thinking more of the clearance issues and it .001 over bearings didn't get it enough...it's going to need some work. Again.....need to start with that line bore job.

You sure that offer to take it all back isn't a good choice??

This could get expensive if machine work is all whacked.

JIM

gkull

I agree with the plug the bypass. About a year ago we started using Joe gibbs break in oil. We adjust the oil weight to get the correct hot pressure levels in all of our race motors. Did the dyno in use have oil temps on the print out? Oil temps can get very high under full loading of non dry sumped motors

This is just a thought. Detonation causes extreem pressures on the rods. We breakin and dyno all motors using 110 leaded sunnoco. Even before you can hear detonation you can be in the over pressure area. I work on some high end motors and we don't chase high dyno numbers. we are very careful about max timing and A/F ratios before we do full or stepped pull runs

http://www.joegibbsracingoil.com/pro...kin/index.html

UBETRUN

I couldn't buy the parts for what I paid for the motor.

The Dad knows what he's doing so I'm optimistic that it's bored square and won't require major machine work. [insert crossed fingers emoticon]

UBETRUN

I don't remember seeing an oil temp monitor but the motor never got so hot that you couldn't hold your hand on the block.


Timing was very conservative and A/F was rich. We tried to give the motor every chance but with the bottom end covered in grinder grit, it was over before it started.

UBETRUN

Agree 110%, this is the last motor I buy instead of build.

Agree again, pay now or pay later certainly applies. I have lots of other toys so I'm not going to rush this one.

That's what the guy that owns the shop said. If it's a good crank, the bearing material should come off with a good polishing. He said that on his high dollar cranks for the billet motors, it takes a catastrophic failure to hurt the crank because the journal material is so hard, bearing material will smear on the outside but never gouges. Mine isn't a $10K crank but using the precision fingernail test, we could not feel any scratches or gouges.