Can I use vin M pistons in a vin J 3100 ?

[mongo]

With all the other good news you have given me I guess it was too much to hope that the rear cam bearing locked rather than spun when the cam broke? I guess I can't have everything work out in the end.....

[mongo]

Just a quick followup (I feel like there should be more of that on every forum I am a part of):

Bought a car... 3100 motor with leaking intake gaskets. Drained the milkshake... replaced the gaskets... did a valve job since I was there... disassembled and cleaned out all the lifters... put it back on the road. Ran like a champ! 2000 miles later, the cam broke. I tore the motor all the way down and found two bent valves, the broken cam, an oil pan full of metal, and a spun rear main bearing.

Not really any parts left on the motor are worth keeping or rebuilding. My personal experience is that once the cam breaks, the motor is only worth its weight in scrap.

[3400-95-Modified]

Well let me explain why this happened...

When you get a milkshake your lubrication is killed so not knowing how long the previous owner ran the engine with that leak then the bearings were probably already severely compromised... Seeing how you did not inspect them or replace them then the failure is directly related to that leak. The cam probably had half spun bearings and then seized after you got it running again because they were so bad. Snapped cam motors yes typically result in a lost cause but you can have the cam journal overbored and get larger bearings to fit and re-use the block. The rest obvioulsy is only re-usable if the crank can be turned to clean up and not be too far undersized.

[mongo]

I knew why it happened... I was just surprised at how extensive the damage was. I figured the cam would have broken before the mains got damaged due to their distance from the oil pump and the main galley. I guess that reasoning only works under a low oil pressure condition not a low lubrication condition.

The previous owner was a coworker so I THOUGHT I had a pretty good idea of how far he drove it. My mistake.

Sure, that crank can be turned and the block bored (cam and cylinders) and honed. Technically all of the parts are reusable but it is not really economically sound to do any of that given how inexpensively parts can be found in ready to use condition.

I had a 50 Buick with a straight 8. It spun a bearing. I had the crank re-welded by a specialty shop and ground back down. I don't even care to remember what that cost me but I think it was in the $300 range. Couple weeks after I got it back, I was at a shop for a different part and mentioned the crank. Guy had a rack of them in usable condition for $50 each..... yeah.. that crank was reusable... but for the cost of repair I could have had 6 cranks that didn't need repair...

[mongo]

Got the motor re-installed last weekend. Car had been sitting for 9 months. Tried to start it and the battery was shot. I got a new battery and the starter was shot (probably from trying to crank the old motor). I put on the starter from the donor motor and it fired right up.

Now I just need to track down a minor leak (I think the water pump seal went bad) and a few other minor issues..