what's wrong with this picture?

pat in Santa Cruz

pat in Santa Cruz

Well-known member
I tore down the engine from a 1931 A coupe last week. This car had a pounding center main about as bad as I have ever heard in addition to a terrible timing gear noise. The rods all looked good, so did the rear main. But this center main was destroyed. The cause should be evident from this photo.
4784913787_a93b502ddb_b.jpg
 
Heh heh heh..... It took me a minute. Do you think possibly some stray babbit material got circulated around and plugged the oil hole? Doesn't really look like it, but...


Deron
 
The original pour was into the oil line and was not cleaned out. Here's a photo of the bearing material I pulled off. You can see how the melted babbitt formed into the oil line. The crank pin was worn .010 out of round. There is metal everywhere mixed in with timing gear teeth. Judging from the clutch plate wear, I'd say the engine has about 2-3 thousand miles on it. There were other oddball repairs as well, such as knurled pistons and the cam plunger was in backwards, with the spring riding against the camshaft face. The rebuild plate says "Densmore Engine Re-Nu"

4784913897_dea647828b_b.jpg
 
Tom Wesenberg said:
I'm wondering if the babbit didn't overheat and the melted babbit covered over the oil hole and grooves?
Click to expand...


It is pretty far UP the tube, but I suppose it is possible. But there is no sign of melted babbitt in the other bearings. I do think the grooves are worn (or pounded) away as the other bearings are grooved (by a very crude tool).
 
What did your engine sound like with that funky center main journal flapping about with no babbit and not much if any oiling?

Would one be able to hear it in order to locate it with a stethoscope?

skip

Just asking. Mine does not make those sounds as described. Thank goodness!
 
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skip said:
What did your engine sound like with that funky center main journal flapping about with no babbit and not much if any oiling?

Would one be able to hear it in order to locate it with a stethoscope?

skip
Click to expand...


It sounded like the engine was going to knock itself to pieces any minute. One did not need a stethoscope or even good hearing... maybe earplugs would have made it more pleasant to listen to. If you beat against the block with a 2 pound hammer as hard as you could, it would probably sound similar.
 
skip said:
What did your engine sound like with that funky center main journal flapping about with no babbit and not much if any oiling?

Would one be able to hear it in order to locate it with a stethoscope?

skip
Click to expand...

When I first bought my 29 Tudor the center main was out. I mean out as in NO babbit at all. The engine ran and sounded good up to about 1,200 RPM, then it shook and rattled like a worn out threashing machine. I only drove it a few miles before pulling the engine and tearing it down.
 
Pat,
"Densmore Engine Re-Nu" has been out of business for 10-15 years,there come back
rate was about 60%, LOOK at everything real close.
Dudley
 
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