Engine lockup

[Chris]

I was breaking in my engine last weekend and it locked up. I am just looking for the best way to investigate this without tearing everthing down until I know what caused the problem.
A little background, the engine fired quickly I got the timing set and ran it for about fifteen minutes at 2000 rpm to break in the cam. oil pressure was good(reading on mechnical gauge) no odd noises. I shut the engine down to check out coolant leak at the raidator. went to fire engine again and it crank over tried to fire and locked up. The only thing I have done at thsi point besides is drain the oil to look for metal, all is clean and pull the starter. The starter was stuck in place and a tooth chip on the flywheel, but the engine still will not crank.
Where do I start?

[jinpdx]

pull the sparkplugs and see if it turns over then. possibly has an internal leak that filled one of the cylinders after you shut it off. just a guess

[ironman_gq]

yep pull the plugs, try to turn it over by hand with a wrench on the balancer nut, if it turns the problem is probably a locked up starter, if it doesnt I would pull the valve covers and see if any of the valves are stuck/ bent/broken pushrods, if the motor had good oil pressure and wasnt running hot there aren't too many things that could cause it to lock up that you wouldnt be able to hear/smell.

[Goose]

I third the pull the plugs and turn it gently .. It might have leaked coolant into a cylnder and hydro locked it..

[Chris]

I was wondering what the chances were of enough coolant getting in the cylinder and hydrolocking. I will pull the plugs and check it out. Thanks everyone.

[ironman_gq]

when you shut the engine down the air in the cylinders will cool and contract and that may draw coolant into an otherwise dry cylinder as normal cylinder pressure would stop the leak. Did this engine by any chance have problems with boiling over? or is there any kind of black oily stuff in the coolant? or coolant in the tail pipes/oil? all these things lead to a leaking head gasket.

[rollen dean montoya]

it sounds like a cylinder filled up with fluid.

[Chris]

An update, pulled the plugs did not see water in any of the cylinders. With the plugs out the engines turns over by hand without any problems. No noises. Drained the oil no metal. Spark plugs on cylinders one and two had some carbon deposits on them and six had some deposits possibily from coolant. If coolant did get in where did it go? Is the best thing to do pull the head and check everything out? Thanks

[ironman_gq]

if it got in and its not still there it would be in the exhaust or the oil. deposits could be from assembly lube.