Freeing up a Flathead V-8
 

I just picked up a seized flathead V-8. It has been sitting outside for many years. It's probally a lost cause but I figure its worth a shot. I'm thinking of putting it in a empty 205L oil barrel and let it sit until spring. I'm going to take the heads, clutch plate and oil pan off. What should I put in the barrel? I know the molasses mixture removes rust but will it free up a stuck motor? Any sugestions?

Molasses might work to free it up - if there is rust in the cylinders. If you don't have anything you need the barrel for, it can't hurt. I'd probably remove the flywheel just to get rid of the excess weight. It can go in the barrel along with anything else that needs cleaned.

I've only done the short term disassembly on stuck engines which usually involves breaking the pistons that won't come out naturally. The rings can fuse to the cylinder walls and be a bugger to get out. My process involves force and cans of PBlaster - penetrating oil.

Before the long winter soak, try some Marvel Mystry Oil in the cyl.
If that doesn't do it use diesel fuel in the barrel.

I've never seen the Marvel Mystery Oil up here in Canada or I would try that. If I use Deisel it will probally cost at least $50 to cover the block. I noticed it had a C8CM head on one side and 8RT on the other. When I get the oil pan off, I'm going to see if it has a Mercury crank. It's a C1BA block that was in a '48 Mercury M-3. I'm thinking it had been rebuilt at some time or swapped.

To use molasses during the winter your going to have to find some way to keep it heated and not in the house, the smell will drive ya out.

If you need another one, I have a few and I'm not that far away.

51 dueller look up under Kano Laboratories or Kroil. You should be able to order direct or they might find someone in your area that sales it. This stuff is insane we use it were I work all the time in industrial applications. Fill the cylinders with this stuff and it will come loose. This is some crazy stuff, I don't know whats in it that makes it work but it does.

What's the mix rate on this molasses mixture? I hadn't heard of it before. However, I have heard a can of coke will help to free up an individual cylinder, but that it can also make the cylinder walls brittle. Good Luck

I got my freed up (it sat for 35 years) by mounting it on an engine stand and rotating it so that one side of th engine was pointed straight up. I filled the cylinders with penetrating oil and let it soak for a couple of hours then repeated on the other side. Then I soaked up what oil did not drain past the rings, took a short 2x4 and smacked down on a piston wiith a bid G-Dangit hammer for a couple of minutes. Sooon you will be able to tell whcih piston will move the engine clockwise and whcih will move it counter clockwise. I would move back and forth between these cylinders. It moved slow at first but it did eventually come free. This took 3-4 hours. Feel free to stop occasionally and soak with penetrating oil.

I know people have had luck pouring oil down the spark plug hole with the eingine in the truck or in it's normal upright position. The problem I had with this method is that I could only soak about 1/2 of the cylinder if I was lucky. There always seemed to be a vavle open that prohibited me from filling the cylinder but the biggest problem was the angle at which the cylinders sit wouldn't allow me to fill up the area above the piston.

I wouldn't use coke or anything else sugary. That was done to vandalize engines when I was a kid (never by me and I'm serious about that).

For some reason, I can't edit my post, but I was unaware of that aspect of using coke in a cylinder, I will remove it from the post as soon as I can

If it has been sitting outside chances are the cylinders have pits on the walls and it will be hopeless. I am assuming it seized from sitting for a long time.

Nevertheless it can't hurt to try soaking the cylinders in oil. Then turn it if you can until it frees up.

Mo52merc, you can only edit a post within 1 hour of posting it.

I wouldn't worry about the coke advice too much as I don't think too many guys will try to run it thru a good engine. Using it on a stuck engine where it will be cleaned out shouldn't hurt anything. I think the issue with vandalism was about fouling of plug tips. More hassle than anything serious. I never did it either, but my dad ran a gas station back in the day so I heard lots of stories. Some might even be true.

I seem to remember a thread on whether or not sugar will even dissolve in gasoline - don't remember the outcome of the discussion however.

i got an old flathead free by letting an equal mixture of automatic transmission fluid and Marvals Mystry oil soak in the cylinders for a week, then got it to turn over with a big wrench. I just got a 1946 Ford 1.5 ton truck that has a flathead V8, it's locked up and will be soaking once it's delivered.

Just dug up this ancient thread. My recently acquired '47 is soaking right now. It's been 3 days. Approx equal parts pb blaster, diesel and marvel. Unfortunately, the hood was off and the top of the oil bath air cleaner is what some of would call a funnel. Loosley threaded nut with no gasket. Perfect route right into the open cylinders. I don't hold a lot of hope, but I don't know how long it was 'hoodless'.....

ATF and Acetone mixed 50/50 is the best penetrate I have seen, The military
has used it for ever..
And sugar won't desolve well in gas. But honey sure as heck will. It cooks the pistons
to the cyl. walls and they are there to stay.

Try it on the Ex wife's car sometime. Just don't leave any prints.