The Stovebolt Site Forums The Shop Area Engine Shop Copper bearings! Probably for racin'!

Hahaha, I have my pistons out right now for a ring job, and am highly amused by the condition of my rod bearings, as they're quite coppery. Probably special racin' bearings. After I get it back together, I'm headed straight to Bonneville. Hahahaha.

Here's a couple of 'pitchers for your amusement.

http://i221.photobucket.com/albums/dd45/HomeCrafter/IMGP0001-15.jpg

http://i221.photobucket.com/albums/dd45/HomeCrafter/IMGP2288.jpg

That's a very interesting condition . The technical term for it is:

WORN OUT!

Insert bearings are built up in layers. The backing that contacts the connecting rod is made of steel, then there's a layer of copper (what you're seeing), then there's a layer of soft bearing material such as Babbit or other alloys, and then a VERY thin flash coating of pure tin, just about .0002" thick. It's there to allow the bearing to wear-in quickly to any imperfections in the surface of the crankshaft.

Finding bearings worn down into the copper as uniformly as those are indicates you've gotten all the mileage possible out of that engine without having a major catastrophic failure. Good timing on the teardown!
Jerry

Jerry,
how would they run with that much wear and still hold some pressure?

Fiddlesticks.

Now you see, if my rods look like this (runs fine, doesn't really even knock), I'll bet the mains look the same. I guess I'll pull a main cap and look.

This might be a dumb Question, but can the mains be replaced with the block in the truck?

I guess I better open and measure up the old 216 I have lying behind the garage.

I've been roaring along running straight 40 oil, I was just planning on doing the rings you see, to stop the smoke.....

My oil pressure is still about 20psi hot, running on the highway, and about 5 at hot idle.

So, (you can see this coming can't you?) If I just put these back in the engine for a while.... How long do you figure it'll last? 5000 miles? And uh, what exactly will happen? Seizure? Or will the copper wear down, and start to knock like the Hot Rod Lincoln? (I'm sure you've heard the story of the hot-rod race?)

I'd suggest using some Plastigauge, and see what the clearance is. I'm going to venture a guess it's going to be .003"-.005". I wouldn't risk the health of the engine over the cost of a set of rod bearings, especially since you're that far apart already. If the bearings continue to deteriorate, they're going to overlap, one shell will wedge itself over the other one, and the rod will lock up. It breaks just under the wrist pin, and commences to saw its way through cylindedr walls, the water jacket, and probably the oil pan. It also makes some expensive noises in the process. Other than that, no problems that I can see.

Has the engine been using lots of oil, and probably doing its best to imitate a mosquito fogger from the road draft tube? If so, the combustion gases getting into the crankcase form acids that eat everything, particularly connecting rod and main bearings.
Jerry

As long as the oil pump can supply more oil than the bearings leak away, the pressure will stay above minimums. I've intentionally built engines with .003" clearance to let 'em wind up quicker off the turns. We would just install a high-volume pump to keep up with the leakage, and run 40 or 50 weight racing oil. Federal-Mogul used to make wide-clearance racing bearings just for such applications. Since they were for intentionally short-life engine applications, they didn't put the tin flash coat on the bearings, and used a harder alloy on the "soft" bearing layer. A "high-mileage" race engine would have less than 1,000 miles on it when we pulled it down for a rebuild.
Jerry

Jerry's description of "worn out" says it all. You are lucky you didn't spin a bearing.

Okay. I accept it. I pulled the caps off the mains and checked them, they look fine, no copper at all.

I'll order some rod bearings in the morning. The consequences sound pretty dire.

Yup, I've been receiving a village subsidy for mosquito and dust control, I've been using 1 quart oil per tank of gas. Hahaha.

That's about the oil mileage I was getting with my 216 for the first five years I drove it.
Just had the short block completely gone over and reinstalled it in September. 4,000 now,
two oil changes, one at 500mi. the other at 2,500, including the break-in she's only used
about a 1/2 quart total.
Figure I went thru several hundred bucks worth of oil alone before I finally bit the bullet
and did the rebuild.

Agree with the guys on those bearings, the Babbitt is all worn out of them. The copper is
a base for the Babbitt to bond to, seen it show thru many times but usually only in the
center of the bearing, never saw the Babbitt completely gone.

Denny Graham
Sandwich, IL

I always like to get full value. I once rod my motorbike to my brother's place in Red Deer Alberta, and when I got there, the cords were exposed all the way around the centre of the rear tire....full value.

Now, while I've got your attention here, my con rod journals measure about 2.3985". The bearing shells I pulled out are marked as:

1950 CP
Fm
51
010US

A couple read 68 where the 51 is.

I assume these are 010 Undersize bearing shells. I have learned to never assume anything when out of my depth! Better to ask you fellows!

Thanks for the help, as always.

With that kind of wear, copper being harder material and who knows how long it's worked in that condition, I would suspect the crank jounals need grinding... rods and mains.
Jerry W.

Yes sir, the 010 would mean .010" under.
Great that the mains look good!
Jerry W.