I am rebuilding a 77 camaro LT for my son. I bought a new 350 chevy crate motor(290 HP). After installing the motor in the car we set everything up like we were supposed to. Then we started it and let it for about 2 mins. Then we started putting everything else back on the car and didn't start it until the next day. It started and ran fine for another 2 mins or so the next day. But 3 or 4 days later when we tried to start it, It turn over very slow and would not start. We replaced the starter and had the battery check. With the battery and starter ok we still couldn't get it to turn over fast enough to start. It seemed like something was holding the motor back so I tried to turn the motor by hand. I put a torque wrench on the crank bolt with all the plugs out and pushed until I was at 100 ft lbs of pressure and it still wouldn't turn. Can anyone give any suggestions? Thanks

I'll take a stab at it. I am thinking maybe hydro-lock? Maybe you have a ton of fuel in one or more cylinders and liquid does not compress. Try removing the spark plugs and see if it will turn over.

Why did you only let it run for 2 min?

Could be anything. Seized bearings, seized transmission, warped parts, broken parts, you name it. Time to take it apart and figure it out.

Does the car roll in neutral (can the transmission move) This might only factor in if the tranny is a manual.

if it's the engine, sure, try it with the plugs out. Take the valve covers off and see if your valve train is bound up.

This sounds like a teardown to me.

Its not hydro-lock. I pulled the plugs out and it is still very hard to spin by hand. The trans is an automatic and I also took out the torque converter bolts. We let it run for only 2 mins because it was late. Could running it for only 2 minutes cause it to be hard to start now? Its a brand new engine from GM. with all new parts inside.

Just curious, but are crate motors broken in before they are shipped out? Are the motors run long enough to break in the cam?

PLEASE say you put OIL in it, right ?

Yes we put oil in it and primed the oil pump. We spun the pump until oil came out of the push rods. I don't know if crate motors are broken in or not.

I have read that some are, and some arent. Break-in instructions are supposed to come with the crate when you recieve it. Maybe you could contact the place where you bought it from? Also, most crate's have a warranty, this might be time to dig that out as well.

I thought GM broke in their engines, on propane or natural gas?