B-1 lost compression

[DollyDodge]

In addition to my B-2-c, we have B-1 ton and a half that sat for about 25 years. We got it running a couple months ago, and it ran ok, enough I was able to drive it down the road for a couple miles and back. Before I drove it we ran it several times from any where from a 15 minutes to an hour. I replace the points, plugs, rotor, changed the oil, rebuilt the carburetor. It took me about 6 weeks from the time I last ran it. I went to start it and it seemd to turn over too easy. Best I can tell it only has compression on the # 3 cylinder. I just pulled a plug one at a time and put my thumb over the plug hole and had my brother crank the engine. No compression at all in the other cylinders. It has great spark, and fuel is getting to the engine. What could have happened. I assume it is either the rings or valves aren't funtioning some how. Is there a way to figure out what is wrong without taking the head off, or some what to fix the problem. It just doesn't make sense to me that it ran ok and now it doesn't. I have a hand crank and I can turn it over without any resistance at all. I can feel it when it gets compression on the one functioning cylinder.

[Merle Coggins]

Sounds to me that you have stuck valves. Maybe running the engine activated some gummed up goop that worked it's way into the valve guides and coagulated once cooled down. If you can get to the valve covers you can confirm if the valves are moving up and down properly. Maybe you can get something in there to help move them back down and continue to lube them and work them loose again. Otherwise you'll have to pull the head and tap them back down, gently.

Merle

[DollyDodge]

Hi Merle: Thanks for the help. I think I can get those covers off, but I will have to see. I hope it is something that simple. It was kind of disapointing to have it not run after it ran for a while. My brother is taking the old truck from here in Bishop to his home in Paso Robles, CA (about 5 hours away). He has a friend coming to haul it to his house on a semi. We took the livestock racks off of the bed yesterday and laid them down on the bed for transport (they are old and rickedy). It is amazing good shape. The speedometer says it has about 20,000 miles on it. It was used on our family ranch but very little. Mostly in the summer hauling hay, and it was used to haul cattle and horses some. Anyway, I hope it will get going again without too much work.

[greg g]

Check the neighbor cylinder for compression also. If its low low or not there, then you might need to get a new head gasket. for a single sylinder problem, I would place my money on a stuck valve. You might be able to loosen it by making sure the cam is down all the way and the wedging a screw driver or small pry bar intot he spring and working it.

I had two that I got to work that way and one that wouldn't budge. Had to take the head of and tap it down a couple times while cranking the engine.

[Young Ed]

Ya I've never seen one with that many stuck valves. Does it roll over smoothly? I know you said you didn't want to pul the head but it really isn't that bad a job and if the headgasket isn't blown you can get away with reusing it just to keep it running. I wouldn't do that on a road worthy vehicle but on a project you can do it.

[DollyDodge]

It rolls over very smoothy, no resistance at all. When cranking it by hand (wiht hand crank), I can feel the compression in the one cylinder, but other wise it is completely loose. Abour as easy as cranking with no spark plugs in place. When I drainged the oil the pan was full of all kinds of crud. I tried to clean it out best I could without taking the pan off. This engine has no oil filter (never did). All I want to do is get it running good enough to be able to drive it on the flat bed for transport. I have taken the head of my B-2 and I realize it isn't too big of a job. The B-1 isn't located in the best place to work on it. May be I should just bite the bullet and pull it off and have a look.

[grey beard]

Dolly D,

Suggestion - since yer brudder's around to help, fire something up that you can tow with, get a chain and drag that truck around a little whilst engaging the clutch in one of the higher gears. You want to force the motor to turn over at higher speeds than the starter spins it. Sure is unthinkably unusual for lotsa' valves to stick. More likely with a vehicle that sat many years is that a lot of carbon has come loose inside the combustion chamber and is holding the valves open.

If pulling it around and cranking the engine with the back wheels gives you more compression, try to get it running, while you're still pulling it. Engines with low compression will start more readily if they are spun fastrer. If it will start and stay running, prop the throttle open at 2000 rpm or higher and mist a cup or three of water into the carburetor throat with a spray bottle. Do this slowly enough that it does not stall. What you are doing is knocking any loose carbon deposits free from the combustion chamber and valves.

I'm not a betting man, but I'll venture the thickest milkshake in town that your problems are related to carbon deposits that have just worked loose from the several heat cycles you have run it recently. Get it going and clean it out - it may live to fight many more years.

Let us know what you find.

Good Luck

[DollyDodge]

My brother will be back on wed, maybe we can have a go at towing it. It just didn't make sense to me that it ran fairly well, then lost all compression. Anyway, I am game for anything once

[lugnut123]

Pull the plugs and you should be able to see the valves through the plug holes. If the valves are up try to tap them down with a screw driver or bolt. I had a stuck exhaust valve and freed it this away. good luck

[DollyDodge]

I will have a look and see.

[Dave72dt]

My turn to guess. Chances are the rings are stuck. It ran fine probably due to surface rust on the cylinders and the repeated running cycles you gave have now removed most of the rust and jammed the rings tight against the pistons, thus no compression. Easy test- squirt some oil down each cylinder and recheck your compression. It might even start that way.

[MBF]

I had a 39 Dodge dumptruck that sat for a long period of time and hung all but 1 or two exhaust valves, and ran on 2 cylinders after a tow

(not very well) but obviously had no power until we tore it down to get the valves moving again. Now I realize that only 1 or two exhaust valves are in the process of being open in any given position of the crank, but if she's been sitting w/o being turned over or choked off on a fogging oil, I can speak from experience that when some of those valves do open when the engine turns over for the first time-that they have no way of closing on their own w/o the head being pulled. Mike

[DollyDodge]

I will have a look next weekend and see what I think and let everyone know.

[DollyDodge]

Well, I am finally getting back to the old B-1. I tried most of the suggestions below (except taking the valve covers off-they are really hard to get to on this old truck). So I bit the bullet and ordered a new head gasket. When it comes I will take the head off and see what I have. The oil in the cylinders did seem to give slightly more compression, but not enough to start. I hope it is stuck valves or carbon build up. I will find out soon.

[Dodgeb4ya]

Was the gas being used to run it old? The gas today goes bad pretty quick. I know of a Plymouth coupe owner that let the car sit with 2-3 year old gas and drove the car-ran fine, then a month later tried to start it- no compression on any cylinder. The gas varnish caused the valves to stick. This engine was a low mileage engine with good oil changes too. I had this happen to me on a low mileage 1950 Dodge 2-1/2 ton sodium valve engine, a seldomly used property maintenence truck- same thing I started it with old gas- 2 cylinders dropped. Had to pull the valve covers, then the head because the valves were stuck so bad. I will never start an old flathead on old fuel- it can be a major hassle!

Bob

[DollyDodge]

It was a gas I had put in the engine and it was a couple months old. Plus the tank was badly varnished from the old gas that had evaporated as the truck sat for 25 years.

[DollyDodge]

I pulled the head yesterday, and all the intake valves, except for the #3 were stuck. The #6 valve was really hard to get to move again. I soaked all of them with Mystrey oil and got them to free up except the #6. I had to help the valves move with a rubber mallet, but I couldn't get the #6 to move with the rubber hammer, so I got a ball pin, and as Merle said, gently tapped it, but before it would move I had to apply a bit more tapping pressure, in any event they all got to working. I put a new head gasket on, put her back together and then it wouldn't start. I finally found a shorted wire under the dash and the old girl fired up and ran. It won't idle without choke, which is a bit puzzling as I have cleaned the carb twice and put in a carb kit. In any even she runs and my brother will be able to drive her on to a transport truck and take her to his home in Paso Robles, CA.

Thanks to all of you for your advice and help on this truck. Those that thought she had stuck valves were correct. Five out of 6 intake valves were stuck. I ran her for about an hour (put in some mystrey oil and gas additive to the crank and gas tank first), then drained the oil and put in new oil. I hope it doesn't gum up again and the valves stick again. Anyway, at least it wasn't anything more than sticky valves.

[greg g]

Put a vacuum gauge on it. If it won't idle wo the choke, you porbably have a vacuum leak between the carb ad the manifold or the maifold and the block. If you have vacuum wipers check the line going from the maifold to the wiper motor. If its cracked or loose it is the most likely cause of a vacuum leak. Its also a good place to attach the vacuum gauge. The gauge will tell you a lot of things about the condition of your engine.

Here is a good primer on interpreting gauge readings.

http://www.secondchancegarage.com/public/186.cfm

[DollyDodge]

Unless I missed something, this old truck doesn't have a vacum line attached anywhere on the carburetor. there is no vacum advance on the distributor, and it has an electic motor for the wipers. My old B-2-C has a vacum line on the carb, but this one doesn't

[DollyDodge]

I looked at the truck this weekend there are two vacumm lines coming into the manifold. The vacum line from the gauge goes into what looks like at air tank under the driver seat. There appears to be a vacum assist on the brakes and there is vacum assist on the 2 speed rear end. most of the lines are 1/2 inch metal, but there are a couple of rubber lines, and they are dry and hard. Lots of places for leaks:)

[greg g]

Well now you have places to start looking. The line outs to the brakes and rear end shouldn't be a problem as there are probably check valves in place.