The Stovebolt Site Forums The Parking Lot Big Bolts Gutted-got it running and oil became chocolate milk

So this is about the same bus that I earlier posted pictures of the engine serial number.. After four trips up the mountain, today we got it running. Sounded great, 60psi oil pressure-perhaps more importantly, the air brake system pumped right up and seemed to work perfectly. This was really worrying to me, I mean it didn't matter how well the rig ran if I couldn't get the park brake released or the service brakes to work.

It got to be too late to try to finish with the dummy tank fuel system and get it down the mountain, so while cleaning up tools, I decided to check the oil, which had been full and super clean like it was just changed.

It's now three quarts over full and so light and frothy that it looks like it came out of my espresso machine :-( My guess is that it blew the gaskets which had simply corroded from 55 years of time and storage, as soon as we started it and ran it somewhat up to temp. It showed no evidence of being frozen out, and hadn't even lost a notable amount of coolant while sitting for a dozen years. It didn't run long enough to overheat. I can't fix that up on the mountain. It's got to be towed home-86 miles, with bonus extraction from an off-road campsite. It would cost thousands of dollars, I'm sure.

The RV part of the bus is spectacular-we're only even having this conversation because of the complete, professional conversion which was done about 18 years ago. The RV part all works as in lights, plumbing, etc. and it even has a (presumably working) roof A/C unit. Even after sitting, it's not moldy inside at all, there's no evidence of water leakage. That's because it is a school bus, versus a wobble box made of sticks and aluminum siding... but anyway..

Not having any luck on eBay finding anything but questionable condition 'as-is' used pulls from wrecking yards. I've been told that these engines are famous for cracking cylinder heads, too, so cores may be difficult to find. I'm open to suggestions as to next steps in terms of even finding the stuff to fix it, assuming I can get it home.

darn it! Runs great, brakes work, stellar RV conversion. But apparently the engine's shot :-(

Air brake compressor mounting aside, the 400hp/550lbs/ft torque Cadillac V8 conversion that I did on my '65 Chevy C60.. could enter the conversation. I wonder how long the engine bay of the '67 GMC 6500 is versus the '65 Chevy C60..

The engine bay is designed for many engines, Caddy would fit fine. If that is such a nice vehicle, except for the engine, a Cummins 6bt would fit in there OK, and save on fuel in the long run. Might need to get a higher axle ratio, Cummins school buses and many other applications come with air brakes and other accessories, so finding an engine should not be hard to do.

School buses are sold after time in many place for cheap, so that would be a good source. They also have hot water heater circulator pumps which are handy in winter.

Ed

In order to get it off the mountain you might consider the following. There is a product called liquid glass that can seal up cracked heads and/or blown head gaskets. Pour in and follow the directions. HRL (Jerry) used such a product to drive a big motor GM across country to deliver to one of our members a few years back. Temporary fix but got the job done. It’s been around for a lot of years. Worth a try.

If it really is thousands to get it towed down that leaves a sizable amount of cash to try other options... Maybe one of those bed mounted cranes to pluck the engine out and carry it down for repair, then haul it back up and put it back in.

Interesting thought on the crane. But I feel like that would wind up being almost as many thousands, plus the unappealing thought of R and R-ing an engine in the forest. I like the head gasket in a can idea, that might be worth considering. A can of liquid glass would sure be cheaper than a tow bill!

Send Hotrod Lincoln a Private Message for his take on the idea. He’s fighting COVID but has started posting some. He may be more comfortable going PM.

What Martin said!!

I have a 500 Cu. in. Cadillac. The reason I haven't installed it in a truck is because I would have to fabricate a compressor bracket and drill a hole for pilot bearing. I am in the trucking business and occasionally I have to get a tow. Have you checked with towing companies. I usually pay about $5 a mile. We care capable of towing our own and whenever I buy a play toy, I tow it myself.

https://photos.app.goo.gl/8Jo5ykDpvRS8Jd8bA

Possibly you know someone who is in the trucking business

V6 heads were not prone to cracking. I would suspect a head gasket or a cracked cylinder. Buy a cheap bore inspection scope. Pressurize the radiator, remove the spark plugs and see if you can find where the coolant is coming from. If the engine is junk, you really need to find a truck engine with an air compressor bracket and a hole for a pilot bearing.

Head gasket in a can for the win!!

I ended up spending the $3400 to have it extracted from the mountain and towed home. I'm glad I did because, even though the carbon fiber reinforced $50 can of liquid head gasket actually worked like a champ-the changed oil is now clean-there were a number of other issues ranging from a disintegrating air compressor oil pressure line to destroyed belts and rusted pulleys to a barely moving frozen clutch pedal (the clutch and idler linkage is fine, it's just frozen under the dash) it would have been a far more expensive, unplanned emergency tow if we'd tried to drive it.

Now it's in the yard and it doesn't really need to move expect maybe back and forth when I have some more gravel brought in for the driveway, but at least the engine oil isn't full of coolant anymore. I sanded and painted all the pulleys, then installed new belts so at least now it can be driven around the block and not throw any of them.

Now, over the next year or so til it needs to move on the road again, I can work on the electrics-none of the vehicle's turn signals, hazard lights, or other electrics other than starting and running, are working at all. Not even any brake lights. Well, two of the four clearance lights work. The air powered wipers are also stuck-the actuation levers are completely frozen so they can't be activated. Needs radiator hoses and other rubber too.

Regarding the Cadillac V8 and needing to drill a pilot bearing.. on my C60, the original flywheel had a pilot bearing already in it, and the distance from the back edge of the block to the crankshaft flywheel mounting surface was the same. There was even a steel adapter plate already present between Chevy engine and large round truck bellhousing. I just had to drill a couple of different holes in it! The big locating dowels also lined up, IIRC the distance between them and location relative to the crank centerline is pretty much a standard across GM engines from 1948 onward. This would be for another thread, but for the curious: https://cadillacperformance.com these guys sell all manner of Cadi hop up parts including adapter plates, manual transmission flywheels (for 11 or 12" clutch, not the bigger one on a 2 ton gasser) and even a press in pilot bearing adapter for the back of the Cadi crank so you needn't have it machined.

nice to have it home!! Persistence paid off, and at least it is now safe at home and not stuck part way down the mountain, against a tree, partly in the ditch, or worse!

Water glass, sodium silicate, etc. worked well getting my 503 from TN to CO, however it is not compatible with normal antifreeze, I took the head off and repl@ced the head gasket, milled the head .090” while I was at it.

Ed