Finally got my knocking 355 disassembled. To my surprise every rod and main bearing has spots that are copper and black colored, or the entire bearing is copper color. I used Clevite 77 bearings. Most also have signs of lack of oil and craters, but I know that is because I was often "lugging" the engine. But why are these bearings with 2300 miles on them this color? Bad crank? Rods out-of-round?

 

All the coating got wiped off is what happened. Got pics? That could help us tell you why it happened

 

heres a rod bearing:

 

What kind of oil pressure did you have ? And did you prime the oiling system before you stated the motor

 

Recent rebuild? Bet you wished you used a plastiguage.

 

plastiguage??

Yes it was a rebuild. I reused the block,rods,and crank. Oil pressure was like 55psi. It was primed before it was started.

 

How exactly did you break this engine in? Start from the first time it was fired...

 

Holy fubar batman!! What were your measured clearances? Did you cut open the filter? What did you use for break-in and running oils?

WTF does priming have to do with it? Two words: Assembly lube. Priming it just washes away the vital components of the assembly lube.

 

Lubed all the bearings with some red stuff,dont know what it was called. Checked all the clearances. Started it, gave it some revs to 3500rpm, then let it idle at like 2200rpm for 15 min. Let it cool started it again with some light revs then shut it off and took it off the test stand. Used Castrol GTX Drive Hard 10W30. First oil change after 400 miles. Second at 1500 miles. Started knocking at around 2000 miles. Forgot to cut open the filter. So what would cause soo much wear? Im gonna have the rods and crank checked soon. Mabey this supports the theory that Clevite bearings suck?

 

I'd rather have everything sent to the machine shop than plastigauged. I plastigauged my first build, didn't save my bearings from warped block mains, had everything machined, including an align bore on my block mains, my bearings were the image of perfection when I tore it down last week, and I didn't plastigauge the 2nd time around.

Cam lube? Buy yourself a spray can of VHT Assembly Lube[8$], good for bearings and bores and anything else you could imagine, no dealing with tear open packages and the can will last forever.

 

Yes, I dont use them either but most of the people in this site get thier machine shop parts from ebay. If one of my engines grenades from an incorrect measurement Ive got a size 14 boot and I know where to go stick it.

 

Arggggg
That looks terminal. Really bad, really sad. Sorry this happened to your engine.

Did you by chance use the wrong 'undrersize' bearings?
Was there a P-10, P-20 etc on the end of your bearing numbers?
Was your crank a standard journal crank. Was it a turned crank?
Were any of the bearings stuck to the crankshaft?
That looks like to little bearing clearance OR lack of lubrication.

Clevite bearings do not suck... who told you that?
ANY bearing would have failed under the same circumstances.

If no bearings were 'stuck' or melted to the crank journals you 'may' be able to have the crank polished.
Have ALL the journals miked. Have ALL the rods miked.
Have the rods checked on a rod sizer to see how out of round they are.
Torque the mains with a set of old bearings installed (not those burned up ones)and mike the main journal bores.

Sumpin went drastically wrong there and you need to investigate until you find the reason.

 

That bearing has spun.
The retainer tab is totally gone on it so.... spun bearing.
I'm judging it from the picture... Am I correct?

Looks like you are going to need to start over pretty mubh from scratch.
Sorry.

 

What were the measured clearances and what were they measured with? The more I look at that thing the more I shudder.

 

I dont remember what the exact clearances were. My friend did most of the building of the shortblock, and he is not inexperienced. Actually I think the bearing in the pic was slightly stuck to the crank, I had to pick at it to get it off. But to the eye the crank looks good, no visible damage. They were the right size bearings, my friend who built it would have noticed if they were wrong when we bought them. When I took the first engine apart, everything looked excellent (crank journals, bearings) So the parts I used were all good at first. Would lack of oil from "lugging" cause that much wear?

 

my guess is if you used the correct bearings you're clearances were way out of spec. just checking clearances isn't enough, they have to be within spec. also plastigage isn't much of a precission insterment, invest in the correct tools for the job. were all the bearing like that? was there no problems with the oil system, like the pick up fell off the pump? did you use a HV pump and a stock pan? that would be another possiability if you ran it at higher RPMs.

 

HV pump,stock pan. Might it have sucked the pan dry at high rpm?

 

That bearing failed from oil starvation. "Lugging" the motor didn't cause that. Lack of oil delivery was the problem.

Check the oil system over very carefully as you tear the motor down. Make sure there's no schmutz stuck in the pickup screen, and that the pickup had the proper clearance to the pan; verify that the ½" plug that goes about an inch into the block casting from the rear main cap register surface is there; check all passages, especially the ones behind the cam bearings, for dirt (they'll be full of metal shavings anyway, and you may not be able to tell how much of what's there is cause and how much is effect); etc. etc. etc.

The crank is toast, no matter whether it "looks OK" or not.

Don't use a "high volume" pump when you put it back together. Use a regular Melling M55 pump, a Melling 55-S screen, a Melling IS-55E drive shaft (metal collar not plastic), and put a Mr Gasket 26 pressure return spring in it, and tack weld or braze or bracket the pickup to the pump cover plate after the proper clearance to the pan (3/8" or so, with gasket) has been established.

I personally prefer other bearings besides Clevite, having seen their quality control essentially disappear over a period of time in the 80s. The last set I used, I took one out of the box, and it already had a big flake of material missing from the surface, a bit like that pic; except the rest of the surface looked (of course) brand new. It was just missing a section. I got another that had a fingerprint in it that looked like it had sulfuric acid on the finger, it was etcehd into the bearing so deep. It may be better now, I don't know; but I usually use Speed-Pro (Federal Mogul). But that's not why the motor failed. It had an assembly problem of some sort.

 

yep very likely. lot of people think they're doing the engine a favor running a HV pump when the end result is similar to the bearing you had in the pic

 

thats one thing i learned the ard way, do not rev your enigne any higher then 1500 if you can for the first time. Since ther isnt really any oil in the system yet you can burn out your crank and maybe bearings??

 

When my friend started his 406 he reved it all the way to 5000rpm. Then later to 8000rpm. No problems with it yet. But it is race built all forged. Anyway, I have an extra brand new stock replacement pump Im gonna use this time 'round.

 

Erm. How about a bore caliper that measures down to .0001.


The wrist pins get 25% of the oil pressure indicated on the gauge. A high volume oil pump is a sure way to gurantee as much oil as possible reaching where it needs to without pressure drop.

Not to mention most rebuilt performance motors run slightly loose clearances, and need higher volume.

I'm guessing any failure you witnessed was related to impropper pickup distance from the oil pan.

I don't know anyone who doesn't use a HV pump in an engine that would even have a hint of performance or upper RPM use.

I've seen rod bearings look like that, which came out of a motor that was built by a guy who mixed up his rod caps. Hrmm.

-- Joe

 

Problem is, you need to hold about 2200rpm to break the cam in.


-- Joe

 

Finished investigating it. Looks like it came down to a combination of overheating+lugging+running rich. The bearings all smelled like gas, so some excess fuel must have gotten into the oil. I was always having a temperature problem but though it was just the gauge. And I can admit that I was lugging the engine, since it had so much gearing and low end torque, I would always just leave it in 3rd or 4th gear to accelerate from under 20mph.

Well a new engine will be used next time and a 2.77 posi rear end to work with the 4.03 first gear. I wont make any of the same mistakes twice.