How long does it take to unlock a flathead V8?

[1950flathead]

My father passed away last year and I inherited a 1950 F1 with a locked up flathead V8. The truck has been indoors with oil and anti-freeze for 30 years, the last time it ran was 18 years ago. I've added about $60 worth of marvel mystery oil down in the plug holes and it's been soaking for about a month now. I've removed the starter and all the belts, but it still won't turn over. Any suggestions on bringing this flathead back to life?

[slowforty]

Try some acetone and auto transmission fluid 50/50 mix . Works better and cheaper. also diesel fuel is good too. Patience is a virtue. It did not get stuck overnight.

[Bruce in southern OH]

I have done several cars that have not moved in 30 plus years, pull the fuel pump stand, add automatic transmission fluid, remove the center head, spray all the lifters with PB, also use diesel fuel and a brush to clean the valley out and lube the lifters. Make sure the transmission is in neutral. Take the belt off the generator and water pumps. The clutch has been stuck several times on two cars I have done. Pull the distributor, add oil, automatic fluid oil, anything you can remove to lube up, it needs to be done. Put car in gear and rock it back and forth, gentle. Add oil to everything you can think of. You will need to drop the mix of fluids out of pan after you break the engine loose. I have always dropped the oil pan and cleaned the sludge out of pan that is always in it and the oil sludge you washed from valley. See if screen on pump is clean. Sounds like a big job, but goes quick. ( yes pull the starter and make sure it spins on the floor with power, it can be froze ) you will need later to spin after it frees up. Drain the radiator, see if the water pumps are stuck.

[Mart]

Pull the heads - pull the intake. Have a good look around. When you can properly see whats going on you might be in a better position to decide how to proceed.

[alanwoodieman]

most of the time I soak them with a mixture of atf and acetone 50/50. usually for two weeks. try to spray upward so that the valves get some of this mixture. then take a pull handle and socket on front crankshaft bolt and attempt to turn over engine, just a little, if it moves back up more than you came forward. leave alone with more of the mixture for a day or so. I have also found that valves stuck in the guides can be the culprit. If so remove the valley cover and soak the valve guides with same. I just unstuck one that had been sitting since 1972--good luck and go slow

[RalphM]

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It takes as long as it takes.
I once freed up a sleeve valve engine, only took me six months.

[Willit Stop]

Mine sat in a garage for 20+years and it started within 2 seconds.Yours might not be stuck as bad as you think.Best of luck.

[FlatheadTed]

After soaking remove the starter and lever of the fly wheel teeth with a crow bar if there's room ,if its real stuck heads need to come of .Maybe soak the pots in Vinegar ,then stripe it all down ,Ted

[Tony, NY]

I read of guys putting a breaker bar on the crank pulley bolt and jack under it applying pressure and leaving it for days. Of course, the cylinders had their dose of your favorite concoction. Check for movement, daily, weekly or whenever.

[tubman]

Originally Posted by Tony, NY

I read of guys putting a breaker bar on the crank pulley bolt and jack under it applying pressure and leaving it for days. Of course, the cylinders had their dose of your favorite concoction. Check for movement, daily, weekly or whenever.

I have found that this works. We've been fighting gravity all of our lives. It's time it did something for us.

[rotorwrench]

I always caution folks that are trying to break an old flatty free. Most things have been touched on to a point. Some folks think it's just a piston or three but any metal to metal surface can corrode and sieze up. Pistons to cylinder are common but stuck valves are just as common. You can break a stuck piston loose a lot of times with a long cheater bar but you will break a cam or follower if it's stuck valves. As was mentioned too, clutch plates can rust to the flywheel and they sometimes take a good bit to break that bond even though it's not technically a metal to metal surface and it realy doesn't lock up the engine. If the vehicle is in neutral it will spin the input & countershaft freely along with the crank but it won't disengage.

[JSeery]

And the one thing not touched on yet is animal infestation. Might be hard to believe but they seem to find a way into an engine.

[1952henry]

Originally Posted by RalphM

It takes as long as it takes.
I once freed up a sleeve valve engine, only took me six months.

Willys?

[slowforty]

I had a friend of mine find mouse nests in the cylinders. Little Bastards crawled down the carburator, through the valves into the cylinders.

[34pickup]

Mine was mostly frozen by the valves stuck and the oil pump stuck. Pistons came out ok.

[swanwaco32]

You will break rings if you don't take it easy.

[cas3]

one of my favorites, if you have a hill, and a skidsteer or tractor, is after weeks of soaking in your favorite oil , put it on a hill, in high gear, and push off and on with the loader. the slop in the drive train acts like an impact hammer. push the slop out, let it roll back. again and again. if its never been out in the weather it'll turn! good luck

[RalphM]

Originally Posted by 1952henry

Willys?

Yes, Willys-Knight, it had been sitting for 25 years. Bad part was after I freed it up and got it running it had a rod knocking. When I told the owner, he suddenly remembered why it was parked 25 years before!
I did fix it and it is drivable now.

[Straightpipes]

All of these methods may get it loose but you still dont know whats going on inside. Pull the manifold and heads and inspect it properly.

[JSeery]

I'm with Strightpipes on this one, what is the point of forcing an engine that's stuck? Find the problem(s) and fix it/them. Why damage it when it is most likely a good engine?