I had been making really good progress on the ’27 touring. I was able to get it to start reasonable, but a long way away from what it should be. The carburetor was spiting fuel. I did a compression check the readings are as follow 1 = 45, 2 = 50, 3 = 50, so far so good. 4 = 0. A big fat goose egg. I am deducting that since the carburetor was spitting a little fuel, the intake valve is stuck open.
So what are the next steps?
First I would try a squirt of oil in the plug hole to see if it makes any difference in the compression reading.
Then, if you suspect a stuck valve, pull the valve cover and have a look at what is going on with #4 cylinder valves. Then probably the next thing your likely to do is pull the head and fix the issue---if it is a valve issue.
Got a '26 runabout years ago the owner said ran before. So messed with it and it did start, but didn't run well at all, #4 plug was sparking, but grounding it out made no difference in the running, seemed like it was on three cylinders.
Well, pulled the valve cover and #4 exhaust valve didn't move. Pulled the head...oops, time for some serious work.
Is this the exhaust?
You mean the one that's stuck open? Yep.
What next? Pulling the head? Would the valve guide be ok?
I would try tapping it down through the spark plug hole first. Spray some lube or penetrating oil in first. Looks like it got pushed up too far. Don't get heavy handed, light taps as close to center as you can. I had an intake hangup once, tapped it down and has been ok.
First get some oil under that valve. Going through the spark plug hole, a squirt oil can can put some oil under the stuck open valve. If you don't have a squirt oil can? You can dribble a little oil in with a straw or stick. Sometimes, just a little oil is all it takes. If the valve won't snap down on its own? Some light tapping using a screwdriver though the spark plug hole onto the valve head will snap it loose. BUT BE VERY CAREFUL and gentle with that tapping. It is not as difficult to bend valve stems as one would tend to think.
USUALLY, once the valve stem snaps back down with the oil you already put under it in there, the valve will free up and begin working okay after running for a few minutes.
Then again, it may not. Usually, the sitting open valve dries out and sticks and just needs a little oil and a minor push. Sometimes, they're really rust and stick, or are too tight from previous work. Sometimes you have to remove the head and pull the valve out.
Drive carefully, and enjoy, W2
I can't reiterate the importance of not using a lot of pressure if you intend to push the valve down through the plug opening. They can bend quite easily. I have taken brand new valves out of the box and had them bent---I have a valve grinder I check them on.
The advice of putting oil to it is spot on, it may loosen back up and be fine, it may stick again. A Model T engine is one that does not pull a lot of oil to the valve train, sometimes it just gets gummed up. You can also try and pull the valve down by the valve spring retainer too, but here again, be careful with using too much force.
Anything used to tap the valve down through the spark plug hole will be meeting the valve head on an angle, and the risk of bending the valve is well up there. I suggest that the valve be pulled down via access when the side cover is removed. Even if you manage to bend it the bend will be below the valve guide and should not pose a problem. It will not take a big effort to set it loose, unless it is rusted, which means head off.
Hope this helps.
Allan from down under
Is this the right time for a bit of ATF & Acetone?
If applying the lubrication thru the spark plug hole doesn't work you might remove the manifold and put oil on the top of the guide before pulling the head.
I say "What Allen Said"...A little Kroil sprayed with the tube on into the exhausted valve chamber...Let it soak in ,,and if it doesn't snap down on its own,,,a little twist will probably do it....If it sat for a long time,,a mouse may have taken up residence in there...Nuts ,seeds,,twigs,,Ask me how I know about that...If I was looking for a new home,,,that wouldn't have been my first choice....
Good luck ,,and remember "We're all in this thing together"..
Is ATF a brand name?
What about some other penetrating oil?
Should I be worried that the top of the valve breaking when the valve snaps back down?
Sorry for all of the questions. But now I am nervous.
I am trying to get it up for a tour in a couple of weeks.
I like the idea of removing the exhaust manifold and lubricate from the exhaust port.
Should I turn the motor over until the exhaust lifter is at the highest point to keep it from snapping the top off.
It is that I am just getting really close to getting it back on the road and I don't want to blow it now.
ATF - Automatic Transmission Fluid
ATF= automatic transmission fluid. If you mix ATF and acetone at a 50/50 mixture it is one of the best rust busters around.
If the valve head breaks when it snaps down, it was going to break anyways--it's designed to take that pounding, but you could rotate the engine some if you're really worried about a big drop. Actually, it's not likely to "snap" back down but ooooze down. After you get it loose, hand crank the engine over a few time to make certain it's not likely to stick again. Yes, if you take off the manifold you can look at the area, and check the valves for being two-piece valves--and if they are, new valves are in order, as the two-piece like to revert to being two pieces!
BTW, looks pretty clean in that valve galley, not many miles on the engine?
You can usually spot a 2 piece valve easily. They have two small holes drilled in their tops, 180 degrees apart and spaced maybe 5/8" apart.
There's no need to remove the manifold to get oil in there. With the valve open the way it is, all the oil you need to get in there will easily flow down to the stem from what you squirt in through the plug hole.
Sorry guys. I have my head screwed too tight into this machine and keep thinking 1920's mode. My modern car brain seems to sit itself on the shelf when I work on the T. I actually have some of the ATF sitting on the shelf. Some times I am a real bonehead.
Cut-a-way view to show, remove plug, valve heads are under the plug hole.
I'm thinking that if you're careful, you can sneak a brass rod into the plug hole and get it fairly well centered on the valve head. That way it's less likely you'll bend the valve stem if you have to tap it a bit hard, (but not too hard).
Honestly, if it takes a lot of force to break it free, you are better off pulling the head, removing the valve and cleaning/polishing the valve stem and guide hole. This though-the-head scheme is fine, if it's just slightly hung up from sitting.
I would spray some penetrating oil on the valve stem with the red straw on the spray nozzle to get it down to the stem best I could.Then take a pair of needle nose pliers and gently grab the base of the valve and twist. If it does not pop down on it's own doing that,you need to pull the valve and work on it.
A quick thought occurred to me. I recommend NOT using WD40 in this application. "WD" stands for Water Displacement", which in and of itself is okay. But it also tends to wash oil away. In fact, it is a good cleaner for cleaning show car chassis and wheels. Applied to already dried valve stems, it can sometimes make the situation worse. WD40 IS NOT penetrating oil. A good penetrating oil (like Kroil or several others) or the home brew of acetone and ATF should help without any deleterious effects beyond smoking when you start the engine.
Drive carefully, and enjoy, W2
you can tap a screwdriver or two into valve spring coils to put more presure on spring. once you get to move a little work it up by cranking eng than tap it down again and again until it frees up all the way.go slow take your time it will be good as new!
I soaked with ATF it. Pushed down the valve. Rotated the motor. Valve stayed up. Repeat the next night. After a few tries and soaking. The valve finally pooped. Rotated the motor a few more times. The valve is now moving up and down.
I have to bail on the project tonight because of church. It is all about priorities, because I need all the help I can get from the big guy.
I will check the compression tomorrow and try again.
I think you found and fixed the problem. I bet tomorrow it'll start right up and purr!
Good for you Steve...
On both counts !
I couldn’t stand waiting to check the compression. I ran home for lunch. Threw left overs in the microwave. Ran to the garage. Ran a compression check on the number 4 cylinder. Good new it is about 55. Now for a very long and anguish afternoon. When the whistle blows, Fred Flintstone will have nothing on me on clearing the parking lot.