So I got this '41 Cadillac this summer... ...which has been stored for many, many years and I never gave any real attempt to turn the engine over. I don't honestly know if it's stuck or not, but since I won't have time for it until spring at the earliest, I thought I'd oil down the cylinders and let it soak all winter before I even tried. If it's locked up tight, no harm done, if it can still be made to run, better to not try to turn it over "dry", I figure. But I'm trying to figure out the best way to do it. Not the best product, but the best way to get oil on the rings and the valve stems. I took a plug out and looked inside with a boroscope but the plug lines up right above the valves, so I can't see the pistons. A friend of mine has one of these engines laying around with no heads or intake so I grabbed these pictures. Seems like if I just dump some Marvel Mystery or whatever down the spark plug holes, the best I'll do is to soak the bottom parts of the pistons, and none of the valves. I can touch the valve stems with the intake off, and it seems to me most flatheads stick at the valves before the pistons stick. Is it worth it to take the intake off and hose down the valve stems with penetrating oil? Should I just try to fill up the cylinders with oil and hope for the best, or is there some method of getting oil to the tops of the pistons/rings due to it's steep angle? I'd like to avoid pulling the heads off right away if I can, but I'm not totally against it. I'm looking for advice on how to deliver the oil, not necessarily what oil to use, seems there's enough threads about that already, although I'm open to suggestions.
plugs out and see if it turns by hand, if it does poor oil in spark plug holes and rotate. Is there oil in the sump?
There is oil in the sump, looks very clean, which is to be expected after sitting so long (any contaminants will settle to the bottom after 50 years). I don't want to try to turn it before I put oil in the cylinders/on the valves, for fear of scratching the cylinder walls or possibly hanging up/breaking a ring or bending a valve. I want to soak all the critical areas over the winter before even trying. And I think just dumping oil down the spark plug holes isn't the most effective way since it won't cover the whole top of the piston due to the angle, nor will it do anything for the valve stems.
be careful removing head bolts, they like to break off. I'd just try to turn it, and see what happens. Then you'll have some idea of what you're in for. If it's free, you're not going to hurt anything.
Remove the heads and spray it down. Reinstall the heads without torquing them. Let it set till spring. Spring time… spray again and rotate the engine. If it all looks good, torque them up.
If you don’t want to remove the heads you could use Mercury Marine Engine Fogg and fog down the cylinders and valves that are currently open. Just go to any dealer that sells Mercury outboard and inboard boat engines. Rotate and spray the cylinders again with the other valves open. Used to use it on our boats. It worked great!
You can probably use the bendy straw that comes on the spay cans to direct blasts at each valve and the top of the piston through a plug hole. You know where they are, kind of bend tube around to aim that way and hose. I recently got one turning and had to take the head off anyhow. There was plenty of oil everywhere. (Liquid Wrench Lubricating Oil is my is my favorite spray lube). Mike
drop the sump and clean it , you can also have a look at the lower end of the cylinders. When I say rotate I do not mean with a five foot length of pipe, by hand should be enough and you'll feel any issues, even via a socket. You could buy one of those little cameras and look down the spark plug holes.
I would just put some oil or whatever in the spark plug holes maybe a little down the carb to get to at least some of the intake valves, and let it sit. if it has really sat for that long another six months ain't going to hurt it now. That is unless it spends that time outside. I guess if I was worried about it, I would try to turn the motor over some. Can you put it in gear and push the car some just to spin the motor some?
what kind of storage did it have over the last 30 years? was it a dry place? I would put it in high gear and give it a shove by hand and see if it turns. just bump it i don't mean push it at 20 mph, or just grab the lower pulley by hand and try to turn it, if it turns easy then you have nothing to worry about. you are not going to break anything with these methods. If it had dry storage chances are it is not stuck
Don't think you're going to have to worry about bending a valve in this engine. Could you use a diffuser nozzle like this snaked thru the spark plug hole to spray penetrating oil on all sides of the cylinder? https://www.eastwood.com/aerosol-nozzle-w-24-extension-hose.html
My take is remove the timimng cover if the engine is stuck and try turning the crank. if that is free, then try turning the cam. Cam is usually what I'd expect to be stuck as the valves may sieze or have crap drop down and wedge them, since the exhaust manifolds are positioned in such a way that dry corrosion and scale can just drop straight down into the combustion areas.. It maybe a way to save taking heads off, as Squirrel said the studs like to break... Oil the bores and fingers crossed if you find everything free. You maybe onto a winner.
Moriarity is give sage advice. Give it a push or light tow in gear and let the clutch out. If it is free it is free. One of the kids in my neighbourhood dragged home a mid to late 30's Oldsmobile that was seized. He poured oil in the cylinders and let it sit a while. There were kids everywhere in the 60's so a gang of us would push it up a gentle slope for a block then get behind it to get it rolling quick. He would drop the clutch and it would skid to a stop. We did that a few times over a week and it broke loose. He got it running but the fuel pump was shot. Guys took turn sitting on a fender holding a rad rod pouring gas into it from a javex bottle. We had a long back alley and the car did the herky jerky up the alley until they got bored with it. It was a crazy as it sounds but fun to watch.
A big thanks to all who have responded. I realize I'm probably being massively over-cautious and I should just give it a bump and see what happens but I really want to minimize the risk and since it's going to sit all winter I figure, why not? Definitely planning to do that before I attempt to do much with the engine, but just thinking ahead on how I'd like to prep it for next year. Unfortunately I'm not entirely sure, I reached out to the family that consigned it to the auction but I do know it was from the estate of a collector who died. Based on the condition I'd say it had to be pretty dry and well kept, all 4 ancient tires hold air, no holes in the top, etc. It certainly looks like a car that was put away in exactly the condition it's in now (60+ years in anything but good storage in Wisconsin would have broken this car in half) so I've got high hopes but anything I can do to improve my chances I want to do. I just ordered one of these, this looks pretty ideal! I had done an internet search for something similar but came up with nothing. I think there'll be enough clearance down the spark plug holes to get the head of that sprayer past the valves and into the cylinders and then I can hose it down with Deep Creep or Kroil or something, this looks like it'll give an even spray and not just sit in the bottom, plus with my boroscope I can probably snake this into the intake through the carb hole and up into the exhaust manifolds to hit on the valve stems somewhat. I think that's what I'll do, I'll blast it with this sprayer head, let it sit until next year, then I'll give it a bump in gear and see if she moves. Maybe the oiling is unnecessary, but it certainly won't hurt it to soak in oil for the next 6 months or so.
you can tell what kind of storage it had by looking at the bottom of the car... is it covered with rust? grab the lower pulley by hand and try to turn it, It wouldn't have been here for 5 minutes before I would have tried it....
I don't think I'd try to fill the cylinder completely with penetrant. But every couple of weeks or every month when you think about it I'd give them all another good shot of Kroil or whatever you decide to use. Then maybe see if you can get it to roll over a little by hand.
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