It has been about a year since I got this old truck started after sitting in a barn for 30-some years. It runs very well except for a miss that I have determined to be an exhaust valve on the #3 (third from the front) cylinder. I can see it in the open position with the plug out, and rotating the engine produces no movement from the valve. This evening I ran it to get it hot then removed the plug and poured a little mystery oil in there, but of course the majority of it goes into the exhaust pipe. I have also removed the RH inner and outer fenders to get better access. I would like to tackle this without removing the engine if at all possible, but I don't mind pulling the manifolds and valve covers. I wondered if any of you flathead guys might have any ideas on how best to go about it?

 

On the flat 6, I would think working on it with the valve cover off is the best option. It could also be that the lifter is what's stuck, which you can determine quickly with the valve cover off. A stuck lifter usually means you need to pull the head and get the valve/spring out of the way. They can be bears to break loose.

If it's the valve, can you see the exhaust valve thru the spark plug hole? On V8's, if the valve isn't actually rusted in place, you can use a bent old screwdriver thru the plug hole to try to force the valve down. Do it a few times, rotating by hand, and sometimes it'll get enough MMO in there to start moving on its own.

 

If you can get penetrating oil to the valve stem and let it soak a few days and then tap the valve gently. A screwdriver or other piece to fit though the plug hole and tap down gently on the valve head. If this fails it is not that bad a job to pull the head where you have access to all the valve tops. Of course, if they need adjusted, or ground the manifold and side covers must come off. BTW, I am parting out a 226 and have lots of good parts if you should need anything.

 

Marvel's is probably the best for this tho they recommend to replace one quart of the oil in the crankcase with it, and also add to fuel, not down the carb throat or cylinder or anything like that. That may work too, i dunno.

 

Ross, yes I can see the valve throughout he he spark plug hole, rotating the crank ans it does not move.
When you guys say to tap gently, I am wondering just how much of a tap that is! I have a flat ended drift that I can get on the valve, somewhat near center, and gentle taps on it with a hammer didn't budge it. I wonder if it may be the lifter.

Raystach: how intact is your 226? I might be interested in the whole engine if you'd be willing to sell intact.

 

I did the bent screwdriver trick through the plug hole on my flathead 8. I was able to "gently" push the valve down twice, then crank the engine by hand. It came back up and stayed both times. I was getting ready to do it a third time when I heard a "click" down in the engine. I looked back down through the plug hole and it had snapped into place. You'll be able to very carefully push the valve back down with the screwdriver. But it's not a very safe thing to do......just sayin. I wouldn't stick a drift down in that hole and bang on it.

 

This bent screwdriver, did you use it to pry or did you use the bent end to tap, so that you weren't tapping with a pointed end?

 

Given as how hard and tough valves are, I would not be afraid to rap on it pretty good. Just don't damage the threads in the head Spray solvent right at the valve stem and let it soak. Tap, spray again, spray and tap. Acetone and tranny fluid, 50/50 mix works well.

 

If I recall, about the only think you can do with the bent screwdriver is push down on the valve with the side of the bent end. Just be careful not to use the spark plug threads for leverage. Again, I shouldn't have done it, because you can really cause damage if it's just not simply stuck. But I got lucky and it helped my tired old nasty, gummed-up, sludge-filled engine last another three years.

 

I'd verify it isn't the lifter before doing too much banging on the valve head. You also need to be sure the cam lobe is down or you'll be trying to close it when it's open. Do it when the intake is fully open.

 

Bump. What is happening with this most interesting project?

 

I have removed the engine from the truck and now have it on a stand in my shop. I somehow managed to snap off the head of the stuck open valve during removal of the head, so now I have a nub of the shaft to work with. I've been shooting it with some penetrant while I contemplate removal. I determined that the offending valve is the stuck element, and the lifter is working as it should.
More to come as events unfold!

 

With the engine out and the side cover removed, it should be "relatively" easy to remove the entire guide with the stub inside it. Is there a sign of water being in there?

 

I don't see any evidence of water, but there's some sludge and gum, plus it sat for 20 or 30 years in a barn before it followed me home. Would you think removing the guide is a maching shop job or a home job? I don't see really clear information in the manual with regard to removing and installing the guides, just a mention of it.

 

My old Motor's Manual says this series guide is pressed in. I would SWAG that means with a special tool but nothing mentioned. These are unlike the earlier series which are similar to the flathead V8s and the N series tractors.