The Stovebolt Site Forums The Shop Area Engine Shop seized engine

A buddy of mine just rebuilt his 350 and upon start up it abruptly stopped. heres the info.
This has been his first rebuild the only thing he sent out for was honing the cylinders and installing the cam bearings.everything else he did his self.
Before he started the engine for the new cam to be worked in he turned it over probably about 10 times not started just to make sure the starter was working fine with the fly wheel (earlier it was giving him trouble.)
So about 3 minutes into the cam break in while he was setting the timing the engine just abruptly stopped.
when he went to start the engine up again thinking it was just a timing problem the starter wouldn't turn the engine over and the starter actually got stuck out(engaged) into the fly wheel.
He was having some problems installing the crank bearings when he was rebuilding the engine because as soon as he tightened the pistons down the engine wouldn't spin. but he did end up resolving this issue.
Any ideas before he parts out the engine? we tried using spacers for the starter but we ended up putting all of the spacers that came with the starter and the problem still is there

Is the engine installed in the vehicle, or on a test stand?

I would remove the starter and see if the engine can be rotated any other way: by the fan, with a long heavy screwdriver prying against the flywheel teeth, or putting the trans in high (if installed with a stick trans.) and rocking the vehicle forward and back...

If none of that works, I would suggest draining the oil and pulling the pan and have a look...

Maybe someone who really knows something will be along...

Yea its on an engine stand, we tried to spin the motor over with a screwdriver on the flywheel and a ratchet on the balancer bolt, and we couldn't get it to move. we pulled the distributor and it smelled a lot like gas,would gas getting in the crankcase cause any damage?

I assume he did not do any type of bearing clearance checking as he did the assembly? That one has all the earmarks of too-tight bearings that ran out of lubrication and seized onto the crankshaft. He's probably ruined the crankshaft, or at least it will need to be reground undersize to smooth out any damage. I never assume anything about an engine assembly- - - -everything is wrong until I prove it's right to my own satisfaction.

Do a full teardown and inspection- - -even to the point of pulling oil gallery plugs and running solvent-soaked rifle brushes through all the passages. All it takes is a tiny bit of dirt or a few metal particles to start a cascade of damage that ends up with a locked-up engine. There's no sense in trashing the whole engine over a little damage, but don't repeat the same mistakes that damaged it in the first place.
Jerry

And sometimes its cheaper to let the experts do the assembly, ie the machine shop. Or a machinist.

Yea theses are the answers i was expecting. It was his first build is 21 and in college, so had to cut expense corners and hoped it would work out but this time it didn't. with no real engine building experience him or me. we managed to get the engine building principles down pretty good but obviously not the practice of engine building i.e. the thinking of oh that should be fine. I'ss let him know its probably what he expected.thanks for the help.
And the only real reason hes parting it out was because hes got a lot of pretty decently expensive parts on it that he got cheap on craiglist to build a decent horsepower motor and figured he'd sell the parts and just go out and buy a used stock 350 and just drop it in his Camaro, and just cut the loses.Until he can afford to do it right.
In the very least we got some good experience out of it and had fun doing so.

Now would be an ideal time to find out what happened. Stopping suddenly without warning would make me think a main bearing seized. I think one rod would give a few knocks before coming unglued.

So long as the main bearing didn't actually spin in the block, you may get another crank and bearing set. But learn how to check the clearances. And as hotrod already stated, clean everything. Passages and all.

Used parts out of a siezed-up engine are going to sell for about 25 cents on the dollar, compared to new ones, unless he plans to lie about how they got to be "used". He's going to be money ahead to fix the problem instead of buying somebody else's junk.
Jerry

Mixed up brg. caps or one put on backwards can cause this.

My first rebuild, at about 15 years old was a 283 cid chevy. I knew nothing. I got it together, started it up, set the timing and all of a sudden it made a loud noise and stopped! Come to find out, I didn't know that the pistons had to go in the hole they came out of. When I was trying to figure out what happened I looked down the driver side of the engine and there was a rod sticking out. What a mess, but I learned a good lesson. Maybe you got the pistons in the wrong hole. Just a thought. By the way I'm 61 years old now.