How long does it take to unlock a flathead V8?

[Lawrie]

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

[RalphG]

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.

[JSeery]

Originally Posted by RalphG

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.

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

[deuce_roadster]

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

[deuce_roadster]

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.

[Mart]

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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.

[RalphG]

Originally Posted by JSeery

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

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.

[1952henry]

Originally Posted by RalphM

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.

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

[RalphM]

Originally Posted by 1952henry

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

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.

[Tinker]

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

[big job]

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.

[1950flathead]

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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[Mart]

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.

[GB SISSON]

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.

[1950flathead]

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

[1931flathead]

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

[corvette8n]

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.

[Mart]

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.