The Stovebolt Site Forums The Shop Area Engine Shop fresh 235 just died..help!

Ok guys, here's one for you to chew on for a while...

I'm driving my '50 Chevy with a freshly rebuilt (~100 miles ago) '54 235. She ran perfect-and I mean smooth as silk-until this little episode. About 5 miles down the road, the engine just stops running like I turned the key off. Ran great right up to the point of shutting off. No sputtering or any warning. Also no clunking or other scary noises. Just turned off. Temp and oil pressure were both in the normal range. After rolling to a stop, I try to restart it, and nothing but the click of the starter. Battery is dead I figure. I go to jump it and no change. Battery is fine. Nothing out of the ordinary looking under the hood.

After towing it home, I hook up my daily-driver car's battery directly to the starter post with jumpers to see if it's a bad connection somewhere. Still won't turn over. After 6 or so taps I get it to turn over once or twice really hard, then it sticks again. By now the starter is REALLY hot and it's started to rain outside.

So here I am, wondering what the heck happened and where to start looking. Any ideas?

Thanks,
Carl

Ouch!
It looks like you've got a tight bearing somewhere, sorry to say! I'd start by draining the oil, and strain it through an old pair of pantyhose, cheesecloth, or something similar, looking for bearing debris. Next, drop the oil pan, and check out the rod and main bearing areas for discoloration. Loosen the rods one at a time, and see if it frees up when a particular one is loosened. If not, go to the main bearings one at a time. No crankshaft/bearing problems, it's possibly a tight piston. Not too likely to cause a complete lockup with piston problems, however. Good luck!
Jerry

That's not what I wanted to hear! What would cause a bearing to suddenly become too tight like that? If it is a bearing, I'm surprised I didn't hear any squealing and screeching sounds. Looks like the pan is coming off....I'll let you guys know what I find.

Carl

First, I would pull the starter and make sure it's not dragging or wedged into the flywheel. With the starter off and out of the way, try turning the engine by hand and see if it's free.
Scott

I agree. It's possible the starter has suddenly gone south, but that doesn't explain the sudden stop. Try a long pry bar in the flywheel teeth, and turn the engine backwards to its normal rotation. If a bearing has "overlapped", sometimes that will free it up enough to crank it with the starter. It sounds like you're going to have to drop the pan and inspect things in any case. Hope the damage isn't too bad!
Jerry

Drained the oil, no metal shavings, looks good.
Dropped the pan, everything looks good.
Loosend the con rod bearings one by one, checking for a stuck one, looks good.
Same with the main bearings..looking good...wait, when the rear bearing is loose, the engine turns over really nice! Better take it off to make sure everything is alright. Uh oh..the bottom bearing half didn't come off with the keeper.

A careful look revealed the seam where the two halves meet, and it's not where it's supposed to be! Looks like the rear bearing has been spun. I found a few chunks of metal fused to the side of it, and some rainbow-looking discoloration on the crank right next to the bearing.

Obviously the bearing needs to be fixed and most likely replaced. I'm calling the engine shop first thing tomorrow. This definitely should be fixed by them for free in my eyes; it was driven 68 miles before the bearing went. I used regular 30W oil and it showed great oil pressure and everything the entire time. The only reason I can think of for a brand-new bearing to spin that early into its life is incorrect assembly.

Carl

Was the block line-bored before it was built up? This one sounds like you've got a slightly oversize rear main bearing bore that doesn't get enough "crush" to hold the bearing firmly in the block. Another possibility would be forgetting to torque the rear main correctly. Is there any overlap of the main seal into the parting line area between the block and the main cap? Just a little seal material protruding into the cap-to-block mating area can give an incorrect torque reading, and allow the bearing shells to be loose in the block. Look for little annoying details on this one! I agree, there had to be some mistakes made in machining or assembly, and you need to find out exactly what happened. Don't accept a patch-up fix!
Jerry

The problem with the '54 full-pressure engines is that they're the shim-style main brngs. Perhaps improper shimming, or a streached bolt, incorrect inserts*, cracked cap, or oil starvation was the cause. All 4 of the 235 mains are pressure-fed from the main galley. Perhaps the oil hole in the upper insert didn't line up with the oil hole in block? Just one of many things to check. A shim-style 235 is easy to rebuild, but tricky to diagnose when a bearing fails.

Unfortunately, when an engine has a bearing failure, its best to completely teardown and rebuild. Careful examination of the bad parts will provide clues.

chip

* the 53-55 shim style engines used different main bearing inserts than the 55-62 235s. The 53-55s had dowel-pin inserts, and they shouldn't be able to spin at all. Inspect old bearings closely for correct application and undersize.

Well guys I'm back from college for a couple weeks and thought you'd like an update. I pulled the engine yesterday...5 hours from pushing it into the shop to having the engine sitting the back of my truck. When I dropped it off I told them what happened and the guy said he'd pull it apart and figure out what happened, and it's most likely under warranty. When I find out what happened I'll let ya know.

Carl