Engine Froze on start up. Ideas??
 

After putting 1000 miles on my freshly rebuilt 930 engine, I pulled it out for clutch work, fuel mods, and valve adjustment. Everything worked fine when I pulled it. It took me about 6 months to get everything done, and back in the car.

Because it had been sitting, I primed the engine to build oil pressure. I followed everything in Wayne's book, and it turned over fine and built oil pressure.

I did a final inspection, and everything looked good. I hooked fuel and spark back up, and proceeded to start the car. As it tried to start, I heard a metal on metal sound, and the engine froze. The starter could no longer turn the engine. I tried to turn over by hand, but it wouldn't budge.

I know your not supposed to turn the engine the opposite way, but I tried it just to see if the crank was frozen, and it turned nice and smooth. I then turned it the correct way, and was smooth until it hit a certain point then froze.

I drained the oil, and it is clean. I also pulled all the valve covers, and the cams were still turning. I tried to go through the firing order this evening to see what cylinder it is, but now the engine is completely frozen (both directions). I am thinking I dropped a valve, but the engine only had 1k on the clock, with very easy driving. Also if it was a valve wouldn't it occur when the engine is under load? The heads were completely rebuilt by EBS Racing.

Any ideas what could be going on other than valves? I am trying to rule everything thing out, before I have to pull the engine again...

Thank you for your help in advance!

What happens when you pull all the plugs?

It sounds that a bore-scope could be very helpful in the days to come. Hope you find the problem. Good luck!! Tony.

Since you did clutch work I'd start there. Maybe some bolts were too long or some kind of pressure plate or throw out bearing interference.

-Andy

I pulled all the plugs, it rotated easier, but still hit something.

I was thinking a bore scope as well.

I doubt it is the clutch, I did check it, and it does not seem to be the problem. b/c it turned over fine when I was building oil pressure, something must have broke...

Betcha you lost a valve seat. Back rotate the engine until it stops. Then use a screwdriver and carefully (don't let it bind) Check each piston for upward movement. If all move then use a compression tester on each cylinder and then prepare to pull the cylinder that shows "0". But you might pull all valve covers first and examine the rockers. A bore scope would be better. Good luck.