Stuck/unstuck flat head
 

I have a EAB flattie that I was told came out of '53 car. Narrow pulleys.

The engine sat in a garage for over 20 years and when I found it it was laying on it's side. The was one spark plug and four broken ones on the driver's side and none on the passenger side. I got it home and removed the one complete spark plug, heat the broken ones and use an easy out. The all came out very easily, the broken ones even had the electron attached.

The engine would only move about 10° either way. I didn't want to wreck anything so after dumping penetrating oil in the cylinders and waiting a couple of weeks I pulled the heads off to check out the condition of the engine expecting to see a real mess. Other than the exhaust valves being a bit burnt and coated with carbon the insides look great, very little ridge at the top of the cylinders. I did have 4-5 stuck valves but with a little work and penetrating oil I got them freed up.

Here's my question. As I stated the engine would only move about 10° either way. I took the heads off and tried to spin the engine with a breaker bar on the pulley and the engine turned over and now turns very easily. What would have prevented it from turning before I removed the heads? I couldn't find anything that would have prevented a valve from opening. Any ideas?

Oh yeah, another strange thing, at least I thought, the passenger side head, the one without any spark plugs has a crack on the outside, just below the spark plug hold second from the front. Isn't this kind of a strange place to have a crack? I looked the block over really close with the help of a bright light and couldn't find any cracks in the block. There might be a hair line crack that I can't see with a naked eye but from close inspection I couldn't find any.

Re: Stuck/unstuck flat head
 

The valve get a thin film of a white resin on the stems and stick. Marvel Mystery oil has freed a lot of them for me. Maybe the block was drained and the engine laying over with the passenger side down and enough water was in that spot to freeze and crack the head. There was one on here a week ago that cracked down near the pan rails. G.M.

Re: Stuck/unstuck flat head
 

Those 4 - 5 stuck valves are what kept it from turning.

Re: Stuck/unstuck flat head
 

did you notice any marks on the head, valves or pistons, like maybe they were hitting there? removing the heads would clear the obstruction which was stopping the engine from turning. properly adjusted valves will not stop engine from turning even if stuck open unless the head has been over milled and letting the valves or pistons to hit it

Re: Stuck/unstuck flat head
 

Did you mark lift on the valves? Maybe you have a crazy cam that someone slapped some stock heads on. Unlikely but a thought.

Re: Stuck/unstuck flat head
 

You said the engine was laying on its side. It could have fallen over and cracked the head!

Re: Stuck/unstuck flat head
 

But, if they're stuck closed? Or in between.

Re: Stuck/unstuck flat head
 

I didn't notice any unusual marks on the heads and the pistons look good other than having some carbon build up.

Re: Stuck/unstuck flat head
 

The valves can be stuck in almost any position and most definetly will not allow the engine to turn over. I've had engines with the valves so badly stuck that I actually broke a cam once trying to turn the engine.

Re: Stuck/unstuck flat head
 

Remove the camgear and see if it turns over.

Re: Stuck/unstuck flat head
 

Flatjack9 speaks wise words.

The two weeks with the penetrating oil helped. Removing 4 or 5 stuck valves will do the trick.

That's all there was to it.

Mart.

Re: Stuck/unstuck flat head
 

It turns over fine, it just didn't turn over when the heads were installed.

Another question, are there any differences between the EAB heads and the heads from a truck engine, 8HT(?)?. I'll need to find a either a matching head to two other kind that match.

Re: Stuck/unstuck flat head
 

EAB heads have higher compression than the 8RT.

Re: Stuck/unstuck flat head
 

is there a flat piston head on with domed pistons?, put the head on with out a gasket and not tightened and turn engine over does the head lift when doing that, if so you need more head clearance over the pistons

Re: Stuck/unstuck flat head
 

The only way those heads would cause a problem is if they were excessively milled. Do as Ford1 has suggested. Also did the engine turn over without the heads on before or after you freed up the stuck valves?

Re: Stuck/unstuck flat head
 

OK i just reread your post, and you had a one or a couple of stuck pistons (or pistonring stuck to the cylinder).

Removing the heads was just a coincident.

I would remove the pistons and put in a new set of rings, think there is one or more piston with the rings stuck on them

Re: Stuck/unstuck flat head
 

go back and reread his post, he said he could move the crank about 10 degrees, that is the amount of the movent between the rod and piston as the crank goes over top dead center, he said he could turn engine over with the head off, if so that eliminates stuck pistons , with the head off engine turns, that eliminates stuck valves prevening cam from turning, that leaves either a valve hitting the head or a piston hitting the head preventing movement, my guess is a piston hittting head,

Re: Stuck/unstuck flat head
 

If he said he could turn all the way around except for 10 degrees, in other words, 250 degrees, then one piston hitting the head may have been the problem.

We are all getting worked up about nothing.

The engine is turning, the valves are unstuck.

It's another one saved for a freshen up - lets all be happy at that.

Of course, for a sanity check, it wouldn't hurt to shove the heads back on and see if it still turns over.

The crack in the one head may have distorted the combustion chamber dome down on one cylinder - it's not likely, but possible.

Mart.

Re: Stuck/unstuck flat head
 

Sorry Mart if i sounded a little worked up or overly excited, i was just trying to clarify the possible problem, head on engine wont turn, head off engine turns, that only leaves 2 possiblities, valve hitting the head and wedging or the piston hitting the head, i still think its the piston hitting

Re: Stuck/unstuck flat head
 

I think Mart has it, there may have been some water in the head. Froze while sitting, cracked the outside of the head , and pushed the chamber down against the top of the piston. Paul Selfe.

Re: Stuck/unstuck flat head
 

If one cylinder head had an obstruction, you would still be able to turn the engine for almost one complete revolution, first one direction then the other. He said he could only move it about 10* .

Re: Stuck/unstuck flat head
 

Easy way to find out, put the head back on with the bolts loose and turn it over. If it bumps the head, put another head on and try again. Look to see if the pistons come up past the top of the block, if they do, the block has been skin cut. Paul Selfe.