Hey guys,
My timing belt broke, and when I took the cover off, I couldn't turn the shaft that runs through the head. I took off the head and took it into a local machine shop, and they said it was bad. (The car was so low on oil that it was making metal-on-metal grinding noises... put 2 or 3 quarts in and it stopped making noises and ran good...until it overheated)
The guy at the machine shop pointed out several spots in the cylinder head that were dry and black colored, instead of the usual oily and copper-colored. He said this is where the oil burnt off because there wasn't enough of it and the engine heated up. (Could be why the shaft seized?)

I was going to buy a rebuilt head (cheaper than getting it rebuilt) but I want to check out the lower engine to make sure it's okay before buying a new head and putting it all back together. My question was how to do this.
I heard from the man at the machine shop that I should remove the oil pan and check to see if there are any burnt spots like those inside the cylinder head, which I did, but I cannot tell what is burnt and what is supposed to look like that.

I'm at a standstill... can anybody give me a good way to check the lower engine to see if it is good? I can turn the crank/cam shaft... so I know that's not seized, if that helps at all.
Like I said, I already have the oil pan off, so that might eliminate a step or two..

thanks so much guys. I really appreciate it.
Oh yeah, the car is a 1991 Honda Accord LX.
Thanks!

 

I never had to do something like that, so hopefully someone else on here knows what to specifically look for.

Your other option is to get a used engine. It may be cheaper. Look at a site like car-part.com to find local yards with the same engine as your 91.

 

The things to check are the main & rod bearings, & the cylinder walls. You can turn the crankshaft, to inspect the cylinder walls when each piston is down. It's not going to be a real profound inspection. I expect if it's damaged at all it'll be plain to see.

Seized up main & rod bearings would mean you can't turn the crank. But with the pan off, you can check the big-ends of the rods for looseness. You might not pick up subtle damage to the bearings, but since it turns you're halfway there.

You've got the pan off so you can unbolt the bearing caps. But getting in there (upside-down) with a micrometer... ? Or maybe with the head & pan off, you can just unbolt it from the trans & pull it out...

 

I would inspect the rod bearing the furthest from the oil pump. If you see copper it is worn out. If you don’t I would plastic gauge it with a dry bearing and crank and compare to specs. Look for dark portions of the cylinder walls and scoring.