Technical Mercury flat head. Help

I have picked up a '50 ford business coupe with a mercury flathead v8 ( think the motor is '49) in it, recently. It an older kustom someone started and never finished. The flathead I'm pretty sure was rebuilt and only started a couple time. I looked through the plug holes at the valves and there is very little carbon on them. The problem is, it sat for about 25 years in a barn. I'm pretty sure the crank is free because can wiggle it back and forth a little so that leads me to believe it has a valve stuck but I don't know. I have never messed around with flathead before so I am not sure of a direction to go with it. Any help would be appreciated

 

If it turns by hand that's a good sign. Search on here for firing up a motor that's been siting lots of good advice in there.i had a sticky valve on my flathead I just got it warmed up and poured ATF fluid into the carb slowly that seemed to fix it. But it smokes like hell and you should check plugs after.

 

Welcome to flathead world. As mentioned, do a search, there is a ton written on here and on Fordbarn about starting old engines that have been sitting. If you have a low time engine that has very little carbon buildup, you may get real lucky and not have the typical valve sticking problems. Good luck!

 

Stuck valves can be as big a problem as stuck pistons in some cases. I've seen a few broken camshafts where folks tried to free things up by adding more and more preasure until the wrong part gave out. I would recommend at least pulling the heads and having a good look at the cylinders and the valves. If valves are stuck, pull the intake off whare you can at least get to the intake valve guides to drizzle your favorite penetrating product down ito the ports. The exhausts have to be opened up a bit to get penetrant in there good or you have to attack from the valve chamber. Extremely stuck exhaust valves can require extreme measures to get them out.

If you and get a valve to move at all then you can start to work it more & more with liberal penetrant applications until it finally frees up.

Best of luck to you. Sometimes they just need a good squirt of penetran and a few days to get it soaked in & allow things to start moving again.

 

Great advice so far. You really need to remove the heads and intake but you should also remove (a pain if still in car) the oil pan. You won't believe the crap you'll find in there. Get everything cleaned up and moving properly before trying to fire this baby up. Taking shortcuts could cost you a good engine. Good luck.

 

Would actually be a good time to pull the heads. Lots of reasons. To see if it really is a Merc engine, or a Ford engine with Merc heads. To get a general idea of the condition of the "rebuilt" engine. Could even be rust in the bore causing the rings
to be siezed. Better open her up. That way you will know what you have.

 

Please keep us posted on how it goes. I like sitting by the computer working on motors; I don't get my hands dirty.

Good luck. Good choice for the car and motor.

Neal

ps. We all like pictures.

 

First, pop off the front cover and remove timing gear. Easy, cheap gasket, and you cannot reinstall the gear incorrectly. This entirely separates cam and crank, and allows you to freely check crankshaft and piston ring health, the big issues here.
Next, try rocking the cam to see if you can rotate it. Sounds like all must have at least some play from your initial description.
Pull the heads and manifold...again, easy, and you can reuse the gaskets unless they are petrified with gasket goo.
If you can move cam a bit, pull a bit harder, keeping things gentle, and see if you can get more motion after squirting penetrating oil down on the guide area. As you play with it, try gently tapping downward on centers of valves for a bit of shock.
If no go, do not try applying lots of force to force up closed valves...you can collapse lifters or damage cam, among other things.
If faced with serious stuckness I would start prying down the guides and yanking out the guide clips. I am hoping that this will be easy on a fairly fresh engine! Yank'em out, disassemble springs and keepers, and see what you can loosen. Keep everything in order, and soon you will know if you are going to be able to free and clean the parts or whether you will need some new stuff. You will also be able to see valve seats and ascertain whether they have rusted.
Stuck open valves can very often be freed by tapping down without removal, but if things don't turn you have valves stuck closed and there really isn't any way to safely apply much force with engine together. With assemblies out, you can set them in a vise and try gentle and carefully centered tapping downward to see if things can be saved. Be aware that valves are much easier to bend than you probably think!

 

Thanks guys. I'm hopefully going to really get into it this weekend. I'll keep you guys posted!