The Stovebolt Site Forums The Shop Area Engine Shop A new problem with my 1950 3600

some of you may have read my post in the General Truck Talk forum about my stuck clutch but now for a real problem (I started a a new thread in here at the suggestion of a moderator and my apologies to the forum - when I originally posted I realized immediately that my thread should have been in another forum but I am a new guy and just messed up). While it was cold today (upper 20's) and snow was forecast for the late afternoon, I couldn't resist driving it out of the garage after 20 years. I left it running and was not to concerned about it rolling anywhere because of the dragging brake and of course the flat spots on the tires. Once out in the driveway, I emptied out the back of it pretty much except for the left rear fender that I have to put on and some other tools and parts and also cleaned out the garage so that putting it back in and working on it would be easier. I checked it every now and them to make sure it was not overheating or anything else bad was going on and it was fine it was running nice and smooth - purring like a kitten as they say. When I went to put it back in the garage, I goosed the throttle a bit and it ran rough and coughed and spit a bit and then died. I thought maybe out of gas since there was not much in it so I drove down to the local general store (in my other truck) and bought a couple a gallons. Put it in and went through the under the hood starting procedure since there is no choke. Wouldn't catch so I got out the ether again. Still wouldn't catch but every now and then it sounded like it might start. I kept trying then it started to backfire through the carburetor. Now when I try to start it it makes some very sharp knocking noises that really worry me. I did notice that the fuel filter is pretty well cruded up and will replace that tomorrow. I am concerned that it would fire on the ether which sort of makes me think something has happened to the spark. This has new points, condenser and coil and new wires 6 years ago but there has been no use since then. Then there is that knocking noise, wtf could that be? This engine (216)was totally rebuilt in the early eighties and has less that 20K on it. So now it is sitting in the driveway and wouldn't you know it, the forecast is not good as in more snow and really cold temperatures. I know lots of folks won't use ether for fear of damaging something and I wonder if that is what happened. I'll be putting the new fuel filter in today. I'm a bit bummed and would have drink if it didn't make the acid reflux flare up.

sounds like you stuck a valve.

Gazz,
Is your carb clean/rebuilt? I think it would be worth it to take the carb off the truck and clean it out. If the fuel filter is full of junk, you might just have a lack of fuel.

Was the gas you were using old? Old gas sticks valves.

You might want to take the valve cover off, and turn the engine by hand to make sure the valves are moving, like baldybenny says.

Starting a gas engine with ether is a bit rough on it.

The carb has not been rebuilt since I've owned it./ Before I started it this time, I did submerge the whole thing in some Gunk(?) carb cleaner and let it soak for a few days. The truck fired right up and ran nice and quietly after that. The gas is largely fresh, there may have been some older stuff still in the tank but not a lot - certainly less than a gallon. Six years ago I flushed the fuel line out and drained the tank of the really old stuff. The filter was fairly clean when I started this effort but now is really cruded up. My plan for today is to pull the valve cover and take a look and probably add some Kroil to valves and also to change the fuel filter -maybe add a fuel filter as well.

If you had really old gas in it then you could have stuck valves and the way out is to service the head. Old gas is really bad for the motor.

Also inspect your push rods. I bent one in my 235 after it sat for a while.


When you "submerged the whole thing" in carb cleaner did you install a new carburetor kit?

No, I did not put in a new carb kit, but as I said it was running fine. Funny that you mention a push rod, actually not so funny. When I got the valve cover off I immediately noticed that there was plenty of oil and then did quick scan to see if the rocker arms were all making contact with the valve ends and push rods and there it was, one push rod about an inch and half away from the rocker arm. There is almost enough clearance to pull it out but not quite and when I wiggle it around it does feel sort of bent at the bottom end. What would actually cause it to bend? Stuck lifter? I've never tore into an engine far enough to get at the lifters but I am sure that the head will have to come off. Any advice will be greatly appreciated.

A stuck valve can cause a bent pushrod. That is the weak point in the chain. If the pushrods were stronger then it would strip the timing gear.

Old gas forms a hideous varnish on the valve stems ( and everything really), causing them to stick. When this happens, the valve "hangs" and the push rod moves away from the rocker, then the rod comes back up and smashes into the rocker and bends.

If it is varnish on the valve guides, what is the cure? Do I have to remove the head and have it rebuilt or is there a way to get the varnish off with the head in place? I got the truck back in the garage this morning and since it has been so cold, I have not had any opportunity to tear into it more. Hopefully I will get to work on it starting this Sunday.

I would think the first thing you'll want to do, is take the spark plugs out, and the pushrod cover off, and turn the engine over by hand, and watch to see if everything is happy. You might want to liberally soak some marvel mystery oil around the valve stems, and you might not have to take the head off.

Today I took the plugs out and the pushrod cover off and removed the bent pushrod. The lifter moves freely in its bore and does not look damaged. I used to have a hand crank for the truck but do not know where it is anymore. I probably forgot what it was and made something else out of it! Anyway, until I get a hand crank made, I will not have any way to to turn it over other than with the starter motor. But I wonder if the back fire alone would have been enough to bend the pushrod as the noise did not start until after that. Or was the backfire the result of a stuck valve? Anyway, if it is stuck valve, what are the chances I will bend the pushrod again when I hand crank the engine?
Everything is soaking in mystery oil and Kroil now and I will order a pushrod (or two) tomorrow along with the proper gaskets.
To replace the pushrod, I am guessing that will have to take off the rocker arm shaft/rocker arms correct? I also plan on pulling the gas tank out and having it cleaned and perhaps rebuilding the carburetor. Thanks for all the help!

To reinstall your push rod you can loosen the jam nut on the adjuster. back off the adjuster then you should be able to move the rocker to the side and install the rod.

If its one of the end rods you can remove the hair pin clip.

Try turning the engine over by hand with the fan.

A carb rebuild is a good idea, disassemble it this time. After soaking the removed parts in carb cleaner blow air through all the passages.

The pushrod that bent was the intake valve rod on the cylinder at the very front of the engine. I have tried turning the engine over using the fan but it does not work - the fan turns okay but perhaps I need more belt tension (which seems good enough) but maybe I need more. Thanks again for the help.

Pushing down on the fan belt between the water pump and the generator while turning the fan should help.

Gazz;

Make sure you take all of the spark plugs out of the engine before you start to turn it by hand. You'll kill yourself tryiing to turn it over if you are generating full compression because the spark plugs are in. With all the plugs out, it should turn over relatively easily using the fan.

I also second the motion to clean and rebuild the carb. My Suburban ran rough even after I cleaned and rebuilt it. It was my first time rebuilding a carb, so I evidently didn't do it very well. A fellow bolter friend of mine took it to work and soaked it in the solvent tank for a few days. He then blew out all the holes and passages and put it back together. When he brought it over to the house I didn't even recognize it. It looked brand new. Now my Burb runs like a scalded cat. I can't overemphasise the importance of a clean and blown out (passages cleaned with compressed air) carb.

I can't really speak to your other issues. I'm learning just like you.

The plugs were out. I'll try putting some pressure on the belt between pulleys to see if that will do the trick. I also have a small collection of bumper jack handles that I think I can make a proper hand crank from.
New parts ordered today.

Gazz;

Ok, that is the extent of my helpful advice. If the engine wont easily turn without the plugs in, you may have a bigger problem.

Are all the valves up , could have one bent or timing gears could be stripped and locked up.

Give up on the hand crank, just use the fan it works wonderfully, just don't pull too hard on the fan, I have heard of people getting killed when the fan came apart. I check my fan for cracks and signs of distress quite often and always after I have used the fan to turn the engine. The one the pushrod bent is the one of the valves that stuck. Some times they will stick and then later when things cool down the valve snaps shut and then you are really confused. Another issue you may have is the cam getting damaged trying to open a valve that won't. Just look at the base of the lifters and the lobes on the cam. But it doesn't make any sense, one dead cylinder won't make it not run, I came in with 2 pushrods fell out, and it was still running just not very well. I had a pretty sketchy trip home that time. When you said you soaked the carb in solvent, did you throw the whole thing in there or did you take it apart first? Also on the timing gear issue, does the cam turn when you turn the engine? What are you using ether for? Throw that stuff out. That stuff is like belt dressing. Useless...actually if it were merely uselsess it would be ok, but it is actually harmful to your cause.

Why is ether so bad? Does it cause that much damage??

yes, it is that bad, the only 2 machines I saw people use ether on regularly didn't last very long maybe a year or two at tops.I grew up in montana, spent 15 years in alaska, and the only time I ever even saw anyone use ether was in the woods to start the equipment on the really cold days,20-30 below zero kind of cold. I don't think they even have that problem any more with intake heaters and such. The reason you should throw it out is you don't need it, if you are having to use ether to start your engine you have problems somewhere. I personally have never used it. even though I now live in a moderate climate, it hasn't always been so. Even the old truck with a 6 volt system has always fired right up at 10 below. So no you don't need ether.

Brokenhead;

Hooah. Thanks. I just went out and fired up my 58 Suburban. Started right up even though its about 20 degrees outside.

I'll have to toss my can of ether later today.

Very cold meaning below freezing and sudden stopage can be water if fuel, turning to ice.

Unfortunately, after looking at the engine in better light, I found that I have several bent pushrods. At this point, I can only assume that the bad gas and resulting varnish has caused a number of the valves to stick and I guess this is why it does not turn over by using the fan. Of course it may be worse than that but I don't know yet. My plan is to pull the radiator to have it recored and then pull the head and have it checked out by a local shop. If it is just varnish, could the whole head be boiled in some kind of solvent to free it up or will complete disassembly be required? Why all of that is being done, I can work on the brakes and carberator. An education certainly is expensive!