[Scarebird]

Tom is right. Only disassembly will show the issue here.

[wbnapier]

I've got the preliminary diagnosis from the machinist. Further tear down and diagnosis will be done tomorrow morning by the machinist and Tom S will be there to help as well. Many thanks to him.

I will refrain from comment here until the machinist is satisfied with his conclusion. Should be tomorrow.

If the prelim is confirmed, it will be a good lesson for all of us. It hasn't been touched on in this thread yet.

[mgarblik]

You mentioning nobody has touched on this reminded me of a "locked-up" situation I had with a student's engine about 15 years ago. It was a Buick 455 stage 1 engine and the student assembled it at home. It ran about 10 minutes and then locked-up solid. He had mistakenly installed all the main bearing shells, (1/2 grooved) with the oil hole half in the caps and the solid half in the block. We took it apart, re-line honed it, had the crankshaft re-ground, and cleaned up everything really good. Put it back together and it ran just fine.

[Half-Inch Stud]

Originally Posted by mgarblik

You mentioning nobody has touched on this reminded me of a "locked-up" situation I had with a student's engine about 15 years ago. It was a Buick 455 stage 1 engine and the student assembled it at home. It ran about 10 minutes and then locked-up solid. He had mistakenly installed all the main bearing shells, (1/2 grooved) with the oil hole half in the caps and the solid half in the block......

Inconceivable!

[steve25]

Wow! 10 minutes of main Bearing run time on just assembly oil is a bit more then I would have thought.

[mgarblik]

The ten minutes was an estimate, I was not there. Could have been 6-7 minutes. It ran at steady speed breaking in the new camshaft. I guess break-in lube, no to little load, and some splash lube kept it going for a while.

[MarkS57]

Originally Posted by wbnapier

If the prelim is confirmed, it will be a good lesson for all of us. It hasn't been touched on in this thread yet.

[GTOEARL]

Been following your post and your issues here. My heart goes out for you buddy. Waiting patiently for the results. I hope it’s not too bad. I admire your courage in putting the motor together.

[tom s]

Pics

[Formulas]

Is the oil groove restricted by foreign material?
Local bearing starvation?

Doesn't seem to be located in the block properly wheres the tang at cant see it on me cell phone

One thing I do on assy is after every addition to the engine assy every bearing cap every rod cap I spin it to make sure there is no large increase of torque or binding

[tooski]

Looks to me like a chunk missing at the red circle. Perhaps that's where the tang sits. Also the grooves on this side looks to me to be a bit shorter than the grooves on the other side; as if the saddle was bored too much to one side

[tom s]

the bearing was tight at the very rear and as it heated up the heat transferred to the front of the bearing where the very front still has coating.The autopsy has just begun as the radius on the crank really does not look wider than a stock 455 crank.As said before the owner supplied all the parts from a 3rd party and did the assm himself.Mike was a little concerned as the engine did not look like it was assm in a very clean room.So far nothing has been found that the owner did anything wrong.I think the issue has something to do with the after market crank and the Clevite bearing.I had a engine with a little copper showing at the very back edge of the rear bearing but nothing like this.Tom

[tom s]

I forgot to ask about the spark plugs!Tom

[Scarebird]

Why would the crank be heat blued at the oil feed grooves?

Would a foreign substance heat up if pumped into the oil grooves? Did the rod bearings show the same thing?

[tom s]

Bearing was welded to the crank,had spun.Tom

[tom s]

I will go back first of the week to see what else Mike finds.Tom

[KEN CROCIE]

What about my favorite, #4 ?

[MarkS57]

Originally Posted by wbnapier

If the prelim is confirmed, it will be a good lesson for all of us. It hasn't been touched on in this thread yet.

I can honestly say I've never heard of a rear main spinning like that...ever; but there are others here who have seen way way more things than me. Isn't the rear main bearing the 1st in the oiling circuit? Anyway, if nothing else is found, then a new block maybe the extent of what he would need; assuming the crank could be saved with some machining? Its still in 4 digit territory but could be worse. Deep breath, think of what that few seconds of acceleration felt like and imagine getting back there...over and over.

[tom s]

Ken,the bearing looks fine,did not take a close look at the F&R thrust side of it,will take a look next week.The only bearing that looked bad was the rear main.Tom

[tom s]

Thrust bearing