How long does it take to unlock a flathead V8?
 

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?

Re: How long does it take to unlock a flathead V8?
 

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.

Re: How long does it take to unlock a flathead V8?
 

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.

Re: How long does it take to unlock a flathead V8?
 

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.

Re: How long does it take to unlock a flathead V8?
 

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

Re: How long does it take to unlock a flathead V8?
 

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

Re: How long does it take to unlock a flathead V8?
 

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.

Re: How long does it take to unlock a flathead V8?
 

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

Re: How long does it take to unlock a flathead V8?
 

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.

Re: How long does it take to unlock a flathead V8?
 

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

Re: How long does it take to unlock a flathead V8?
 

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.

Re: How long does it take to unlock a flathead V8?
 

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.

Re: How long does it take to unlock a flathead V8?
 

Willys?

Re: How long does it take to unlock a flathead V8?
 

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

Re: How long does it take to unlock a flathead V8?
 

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

Re: How long does it take to unlock a flathead V8?
 

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

Re: How long does it take to unlock a flathead V8?
 

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

Re: How long does it take to unlock a flathead V8?
 

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.

Re: How long does it take to unlock a flathead V8?
 

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.

Re: How long does it take to unlock a flathead V8?
 

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?

Re: How long does it take to unlock a flathead V8?
 

Also ,how NOT readily availible are the gearbox and rear end parts I sure would not push or tow it to free up.
Lawrie

Re: How long does it take to unlock a flathead V8?
 

Coming up to ten months I've had various fluids soaking in the 49 Mercury truck engine. Fan and gen off so I have room to get the long swing bar and socket on the crankshaft pulley. But so far the only movement is the bolt on the pulley has loosened up. There is a little rocking action back and forth but I think it is just wear in the rod bearings.

Re: How long does it take to unlock a flathead V8?
 

After 10 months why not pull the heads and intake and see what is going on?

Re: How long does it take to unlock a flathead V8?
 

Something not mentioned that helped me once is to fill the block with HOT water. This can help with stuck piston/rings.

Re: How long does it take to unlock a flathead V8?
 

Something not mentioned that helped me once is to fill the engine with HOT water through the radiator hoses. This can help with stuck piston/rings.

Re: How long does it take to unlock a flathead V8?
 

If it's the pistons it will be dead tight. If the valves there will be movement at the crank then it will not want to go further. You have to use your intelligence and work out what is happening. Exercise caution at all times.

Mart.

Re: How long does it take to unlock a flathead V8?
 

Mostly been busy with other things. But I really don't want to open this engine up unless I have to. Then I'd have to buy new head and manifold gaskets to put on an engine that I know is well worn anyway. I'm just looking to get it unlocked so I can at least start it occasionally and move the vehicle. Prevent it from getting any worse so that maybe some day someone else might actually want to go ahead and rebuild the engine.

Re: How long does it take to unlock a flathead V8?
 

When I lived out west there was a fellow who rebuilt old engines. He had a lot of NOS parts for various makes. I had read about the sleeve valve engines, but hadn't actually seen one. He takes out a NOS sleeve assembly and explained how it worked

Re: How long does it take to unlock a flathead V8?
 

This one was a learning experience for me too. I had never seen one before, but thanks to a past car club member who is no longer with us, Rudy Domke, I was able to repair it. I replaced a connecting rod. The piston/ rod sassy actually came out the bottom of the engine.

Re: How long does it take to unlock a flathead V8?
 

I'm just guessing and saying, if it doesn't free up in a couple weeks of soaking; I'd dig a bit deeper.

Re: How long does it take to unlock a flathead V8?
 

Like the Deuce said boiling hot water repeat and repeat, better yet make a home
grown steam generator so simple to make closed container/ water/ propane
fire, and walk away and steam away.

Re: How long does it take to unlock a flathead V8?
 

I took the intake and heads off this weekend to see if I could see what is locked up. It doesn't look that bad, but it will not move at all. I've filled the cylinders with Marvel Mystery oil and bumped each piston with a block of wood. Gonna let it set some more. Patience.
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Re: How long does it take to unlock a flathead V8?
 

Well that gives you pretty good access. You could give each valve a little lift with a fork type tool. See in any are stuck.

Mart.

Re: How long does it take to unlock a flathead V8?
 

I've unstuck two this year. Both were soaked for months in all the solutions mentioned here. One was in a tonner and the other in a 2 ton. I have a skidsteer and towed and rocked them til the cows came home to no avail. Both were pulled, an 8ba and a 59 ab. Both had 2 pistons badly stuck. I saw this method here on the barn and decided to try it. Used diesel, power steering fluid, atf, mmo and everything on hand. A piece of rag is used as a wick. After maybe six hours on fire I was able to pound out the pistons with a bfh and a piece of 2 2/2" pipe, but not until I removed the crank, which is very tough when they won't roll over. Over the years I have had some I freed the easy way and drove for years, but I have now learned that sometimes they are really, really stuck. They are both stripped and honed and I bought two new pistons and a set of rings for each. This winter I will grind the valves and decide which engine to use in which project truck. Bearings, rods etc all plastigauge and measure real good. Don't see any cracks in either with my 3.0 reading glasses on. Hope it doesn't come to this inferno for you. Good luck.

Re: How long does it take to unlock a flathead V8?
 

GB SISSON - "OUCH" I hope it doesn't come to that.

Re: How long does it take to unlock a flathead V8?
 

the last one I tore down there were no rust on the top of the cylinders they had rust from the bottom of the cylinder carb was not stuck only couple valves

Re: How long does it take to unlock a flathead V8?
 

After letting a single cylinder motorcycle engine soak for many months, I finally gave up and used a sharp chisel to carefully break up the piston, the rings stayed intact on the wall, it looked like someone had arc welded the rings in place, I don't know if I have the patience to do 8 of them.

Re: How long does it take to unlock a flathead V8?
 

If I were that far through, I'd pull the motor. There is no bodywork in the way. It would be out in an hour. I had one recently that had one tight piston and one not so tight. The others were actually free, but couldn't move due to the tight ones. The trick is to work out which are tight and which would move. Basically this is what I did. I set it on a stand and tried to pry the crank back and forth while touching each piston in turn. From feeling them I determined which one was the tight one. The looser ones could be felt to be moving minutely while rocking the crank. On the tight one I loosened the big end nuts and then tried to turn the crank away from it (cap still in place) This free play was enough to move the loose ones and start the second tightest one moving. I was able to then set the crank against the big end cap on the tight one and hit the piston with a piece of wood. This started it moving. I was then able to retighten the big end and get everything turning. I then pulled all the pistons and rods. I used lots of lube all round the place during the operation.

Personally I would be reluctant to run an unstuck motor because the rings in the tight piston were really very tightly stuck. There was also some water damage in the bore so that particular motor is still sitting awaiting it's fate. (It'll get rebuilt).

The point I was trying to make is that if the tight piston can be tackled individually it stands a better chance of moving by not having the friction of the crank and the other 7 pistons holding it in place.

Mart.