Guys, I got time and did a copession test on my 48 today.. Should have done this first thing.... Anyways here are the numbers I got for my inline six...
1) 65
2)0 :-(
3)110
4)110 as well
5)65
6)0 :-(

I just added oil to all of them and will let them sit for a day or so... My uncle was asking me if the motor would run one the four and maybe gett compession back in 2,6
Best,
Cody

 

Im no expert but you've got big problems in 4 out of 6 of your cylinders. Pull your head. That won't get fixed with just running it even IF you get it running. I am sure the other guys agree. Probably more than just a stuck valve or two.

 

A compression test on an engine that has not run in a while means very little. I would guess 2 and 6 have stuck valves. Stuck rings are another possibility but 0 compression is probably valves. Use a good solvent, seafoam and if you can get it into the valve stems and rings it may help. Sounds like the engine has not run in a while and you're probably better off pulling the head and going through the valves. So then, "what is the lower end like" should be the next question.

 

I agree that you have some stuck valves. I agree with pulling the head to free the valves. No matter what you do I would recommend dropping pan and cleaning it. If the flat head has a side access cover you might be able to free them thru there.

Good Luck,
Paul

 

The valves can be seen through the spark plug holes. Take a look to see if all your valves are moving. You may be able to soak them with solvent and get them to free up without pulling the head. Be very careful (probably don't try) about trying to push them back down, you can break the head off a valve by pushing off center on a stuck valve.

 

Update after I added oil... Test number
1)120
2)still 0
3)135
4)150
5)150
6)and still 0... Happy tht 4 out of the six are up n 100s... Still have to work on 2n6 should I try n start the truck on the four ???

 

Absolutely not. You'll be filling #2 and #6 with gas, that doesn't get fired off, or if it does will blow back thru the intake, or touch off in the exhaust. It isn't like the valves are going to come free from the rest of the engine running.

 

I've had engines where running helped everything loosen up and get back to working properly. It definitely wasn't the safest thing, but it worked. The most effective trick I have is to get the engine running, and pour automatic transmission fluid down the carburetor. This puts out a huge amount of white smoke, so don't do this inside. The unburned transmission fluid really helps lubricate the valves and can sometimes get them to un-stick.

 

I hear this a lot on the HAMB, it scares me!! I visualize someone reading this, opening up a quart of ATF and just glug-glug-glug'ing it in, hydro-locking the engine, bending rods, etc. Personally I'd try it with SeaFoam rather than ATF, if at all. Just a dribble, or a teaspoon at a time.

If the valve isn't moving at all, I doubt anything but disassembly will free it. If it's moving a little, maybe it could free it up. Depends if it's rusted or just stuck with varnish too.

 

Guys, thanks for the great info.. I think ill try the seafoam. Where would I buy it at ??.. Any tricks to useing it.??

 

Seafoam: Lots of youtube videos of folks using it, probably the best instructions - pick a video that matches the mfg instructions the closest.

Where: Orielly, Advanced Auto, AutoZone, Pep Boys, even wal mart and big lots - just about anywhere that sells auto stuff. (wal mart and big lots are less likely... don't know for sure I have seen it there or not).

I too have a compression problem (1 cylinder 45psi, and all cylinders low against spec ~75psi) so am going to do the seafoam thing as well.

Be sure to post your results, if you beat me to application I'm curious to see if yours resolves

 

On the straight 6, it's real easy to pull the side covers off and apply whatever you like directly to the lifters, valve stems, etc. and >gently< pry on them to help free them up. If you find the valve chest full of crap, you can get it out rather than recirculating it by running it.

 

I should have clarified, pour a very thin stream of ATF down the carb. You have to rev the engine a bit to keep it from stalling while doing this.

At this point you don't have much to lose. With a flathead, you have no worries of a stuck valve hitting a piston. Your biggest worry is that there is sludge that breaks free and blocks an oil passage. Make sure you have an exhaust system without holes so it isn't so loud you can't hear the engine. Start the engine and listen carefully. Diagnose further from how the engine runs and sounds.

 

Thanks I think thats what ill do.. Was going to to that today but its been raining cats and dogs all day....
Best,
Cody

 

slightly OT, but would help the current situation for the OP and I've been curious to see this but can't find it online. Does anyone have a good picture album of a 226 rebuild (I know they are simple simple, little too them, and I have found flat 8 rebuild here and HAMB, but no sexy 6 galleries).