The Stovebolt Site Forums The Parking Lot Big Bolts Just how much twisting will a 292 crankshaft bolt take?

Sentinel prime my 51 gmc has a 292 transplanted in it. I am trying to check this out to install new points coil etc. The engine won't turn by hand. I pulled out the plugs and poured over two day half a big bottle of marvel oil in it. Tonight I got my 3ft breaker bar out and I'm afraid I'm going to hear off the crank bolt. It's only a 5/8th head. It has a five speed prob a Clark can I get to the flywheel from the bottom? I sure don't want to break that bolt trying to get it unstuck. Gee I ran when I shut it off. Famous last words.
Jay

I'd say put it in top gear and rock it or tow it.
If it was running when you parked it, then surely nothing bad has happened.
Safest is to get a small light like an LED and have a look in every cylinder.
It may have got water inm a bore and rusted. How long did it sit?

You can remove the starter and then you can get to the ring gear. Then you can take a bar and put it between the teeth on the ring gear, you may need a block of wood to get the right angle to get some leverage to try and turn it. Using the bolt in the end of the crank is not going to work, and it will twist off if you put to much pressure on it.

I take the bottom shield off the bell housing, it gives good access to the ring gear and the housing its self provide a nice fulcrum point for the flat bar.

I think it sat for at least five years the plugs still logged ok but the threads outside the head were rusty. The weather in Washington goofs up tons of good stuff here. I think my chickens are starting to rust.

High gear, tow is probable the safest. If it is really rusted inside, head off, coke will eat rust after a while.

If its that bad it needs to come apart.

KROIL OIL
From Kano Labs in Nashville.
Priceless!
Beats the beejezus out of all the other concoctions/remedies I,ve encountered.
SOAK the SH@, out of it in each cyl.Thru the spark plug hole and try to turn it as suggested above a little at a time but back and forth.
Best part is You can drain what leaks down past the rings into the pan,strain it and reuse it.
steve sr.

I second the Kroil soak it in for a few days, and then do the flywheel leverage. If that don't work, tear it down.

Don

Before trying to turn it again you should remove the valve cover and loosen the rocker assembly. No sense bending a push rod due to a stuck valve.

Mike B

Tap on the rocker at the valve stem with a rubber/plastic hammer. You will know if there is a stuck valve without going thru the adjustment process. Spray a little penetrating oil thru the spring onto the stem for lube.

Kroil is good stuff but JB80 and PB Blaster work well too. Marvel is a little thick to penetrate as quickly.

I agree on the rocker-tap thing,but adjusting the valves/possible head-work may be in the works,if the Kroil doesn't work. It still may be a good idea to install hardened valves and guides in your head,to accomodate the un-leaded gas,since,more than likely,your 292 was designed to run on leaded fuel. I had an engine that sat for 6-months,that was stuck so bad that I ended up junking it. Of course,it wasn't a "Stovebolt",with readily-available parts,either. I used EVERYTHING but Kroil,and it soaked for 5-years! The # 5 cylinder still had about 1-1/2" of tranny fluid,Marvel,P.B. Blaster,brake fluid,and WD-40 sitting on top of the piston. The exhaust manifold had a crack in it,and condensation got in through the valve.(open 100%),when shut-off,right at the crack). I've heard several people swear by Kroil. I wish I would've heard of it before I scrapped that "Stude" engine. I tried rocking it from time to time too. The truck was cab and chassis,so I dis-connected the drive-shaft,put the transmission in 4th,and put the end of a long pry-bar between the front U-joint.I added a 3'long pipe to that for leverage. The clutch slipped, but that engine wouldn't budge! Hope this helps.

The valve adjustment doesn't get messed up if you just loosen the rocker shaft stand bolts...

Mike B

Good points all! I do not look forward to a tear down its so big I don't have a engine hoist that tall. This was suppose to be a flip truck so I could pay for my 49 and 71.
Tuesday will tell more. Again thanks Jay

There is a guy on the John Deere forums that swears by WATER. He has been in the restoration buisness for many years. He says fill the plug holes with water. Said water caused it, and water will break it loose. ????
I would think if you tried that, it would be before putting any kind of oil in there.

That reminds me of the first factory job I had out of high school. When it got close to Christmas, the old timers kept telling me we all got a goose for Christmas. I asked when they brought them around and they said I had to go to the office and ask for my "free Christmas goose". That's when I knew they were trying to pull a fast one...

Thats funny. But this guy is dead serious. He has a buisness in N.D. and has been restoring old crawlers for many years. I believe his website is: JDCrawlers.com
I never tried it, but maybe he is right. Notice films of deep sea divers at an old shipwerck, it looks like when they disturb the rust, it floats up like a dust or powder.
On the subject of first jobs, I remember the new guy was always sent for "sky hooks" They would keep sending him to another guy to find them, and on and on.. lol.