Stuck Cylinder

[jmooner3]

49 Dodge pilothouse with 50 deSoto flathead 6 -->Cylinder #6 is still stuck. couple weeks with Marvel mystery oil, and a wrench=no go. Pulled the head, couple weeks with Pb Blaster, block-o wood and a hammer...no go. Can't tell if there are valves stuck too any way to verify this? 5 cyl seem free only one bonded and won't pass the oil down.

Waiting on a shipment of Kroil (recomended by several of the experts here) I'll mix up a cocktail for ol' #6...hopfully I can get it freed up. A few have offered advice on what next. WHEN I get it freed up how to proceed.

Some say clean up the cyl and go. Others say hone the cyl with piston in place, still others say pull the piston, hone and re-install. I'd like to avoid pulling the motor and rebuilding if I can...purely a $ decision. I suspect regardless it makes sense to pull the oil pan, clean out the different oils and any shavings...Does it make sense to pull the one piston if I can free it and get new rings I suspect the rings are shot if it's bonded to the cyl?...any other advice to get me to the next step welcome...

My goal is to make this a runner, it aint pretty and I don't care if it smokes and sputters at this point, I want do some learning with my 10 year old and take him for a ride in this ol bucket. We'll refine system by system once we make the next milestone.

We're havin' fun tinkering together, just interested in more input on what is the right thing to do with this stubborn ol motor. Thanks Jay

[greg g]

Part of the problem with the hammer and wood block deal is that you are also trying to spin the crank and the rest of the rotating mass with that one piston. I would think that you should drop the pan, pull the bearing cap off and rotate the crank away from the rod. With the rod seperated from the crank you will only be trying to move that one piston. Some folks have had success with a mix of transmission oil and diesel (or Kerosene) so while you are waiting for your Kroil you might give that a try. With the pan off you can also tap in the bottom of the assembly with a piece of broom handle or similar. Is there a ridge at the top of the cylinder? If so you need to ream that out before you try to remove the piston.

You may want to pull all the pistons as many of use have discovered that there may be broken piston rings involved. Go to Blueskies profile page and then conect to his website

for pictures of that situation.

As far as stuck valves are concerned, you can rotate the cam around by turning the crank shaft and note any that are not moving. Then you can rotate the cam so they are off the lobe and tap them with a rubber or plastic hammer to free them up, checking for movement by continuinng to rock the cam back and forth by turning the crank.

You would be suprised how smoothly and quiet these engines will run even with lots of internal problems. Goodd to hear you are getting you son involved. Always good to have an assistant. But don't just make him hold the light and run for tools, give him some little jobs to do, like maybe removing the oil filter, cleaning it up, sanding it cown and painting it.

My dad always had me hold the light "Hey! Are you watching where the Damn light is pointed, or you watching butterflies again?" So I got discouraged. But I guess enough rubbed off cause I'm still playing with mechanical stuff.

[RobertKB]

Lots of great suggestions in Greg's post. Only thing I would add is if you remove the one rod cap is to put some tape over the connecting rod bolts before you turn the crank so you avoid any possbile damage to the crank surface. If you are going to put new rings on one piston if would be a thought to do them all. You will already have the head and pan off. This way you can check bearings and all pistons and new rings all around is a bonus. You could also lap your valves to make sure they seat well. A bit of extra work but well worth the few extra hours of your time. Like Greg said, these old engines run well even when they have some minor issues.

Working with your son is another great idea. Good luck.

[aero3113]

When I first got my 50 Plymouth I removed the head and pan. Removed all pistons honed each cylinder Installed new rings (many were broken) and new rod bearings. The pan had about a half inch of sludge in it (good to clean that out). Motor runs great.

[JerseyHarold]

One more thing to try is to cut a piece of thin, flexible plastic (like from a plastic milk jug or antifreeze container) and use it as a scraper to get crud from between the cylinder and top of the piston. Just slide it in there and try to pull out whatever dirt you can. It will give your penetrating oil an easier path to the rings.

[1949P17BC]

I'm with Greg on the steps to follow, drop the pan, remove the pistons, (if its a new adventure, make sure and mark each piston and rod cap) with the rod off, that piston will move.

[RobertKB]

I'm with Greg on the steps to follow, drop the pan, remove the pistons, (if its a new adventure, make sure and mark each piston and rod cap) with the rod off, that piston will move.

Good point. Make sure you mark everything and put it back in exactly the order it came apart. Very important.

[jmooner3]

Great advice! Please keep it coming. Makes perfect sense to work on only the offending piston and not the rolling mass of the engine guts. I'm looking at the pan and it looks like it is shoehorned in. This is a 1950 Desoto (25" motor) the previous owner moved the front motor mounts and the rad to fit it in from the top...That said I suspect the original 23" pan would have slid right out from the front cross memeber and cleared the axel and steering linkage...I haven't tried it yet but this pan goes up over the front cross member where the original rad sat I suspect and is tight to the clutch/trans. It looks like there is not enough play to get it out? Anyone worked a 25" pan out of a B1B? Strategy to do this in the truck or am I back to pulling the motor? Pix attached.

Thanks Jay

[greg g]

Looks like droping the cross link from the steering will give you enough wiggle room.

[1949P17BC]

Drop the link (chaces are good the ends will need to replaced) two ways to lknock them off, loosen the nut and pound on the side or buy a pickel fork from Harbour frieight try and not rip the rubber boot/seal. Pull the pan, go ahead and take each piston and rod out make sure you mark the cap and be carefull not to loose the lock washers. I would push #6 down jsut a little and then hone the cylinder and push it back up. As mentioned odds are good many of the rings will be broken and you would be doing this sooner than later. Other things to think about replacing while its aprt Rear Main Seal, Check the Valve springs, replace rings and rod bearings, mains if you can, valve job, clean the oil pump. If the car hasnt run for a while the water pump is ticking time bomb, and while you are it check the water distribtuion tube. Buy a case of brake cleaner and give it a good washing down. Hone the cylinders and you are good to go. May not be perfect but it will run and you can drive. Thats waht we did on my 49 which I still drive every where.

[austinsailor]

Hitting to remove it is close.

Hold a big hammer (like 5 lb or more) on one side of the part the tapered end goes through, then hit it with a 2 pounder on the other side. One or two hits it'll pop loose. This saves the seals.

An old guy in a junk yard in Germany showed me this in 1974. I've used it dozens of times on many vehicles, big and small, and have never had it fail. It'll remove it with less effort than the pickle fork, and puts no strain on the other components.

[Dodgeb4ya]

Hitting the side of any link attached to the steering gear pitman arm sector shaft could send the sharp impact shock to the hardened sector and worm and damage the steering gear !

Be careful about doing this-learned from past experience, now I always use a made for this job 2 jaw press made for popping off tie rod ends.. .

Bob

Edited November 8, 2009 by Dodgeb4ya

[jmooner3]

:DFigured I'd re-post the success for this stuck piston on this link in case someone searches while trying to coax out one of theirs- Great advice from the forum got that offending piston out. Dropped the pan (Thanks for the tip Joel). Jacked up the frame, lifted the engine about and inch, pulled the draglink, and the pan slithered out. Popped off the #6 rod cap and rolled the crank down a bit. progressive persuation on the stuck cylinder. tapping to all out pounding with a 3lb sledge. it moved a bit down, wirebushed the scale out of the cyl and crawled under with a 3/4 inch black iron pipe and my new favorite sledge. got the piston to the top, my boy crawled under and pounded up while I grabbed the piston...We-Win!

[Joe Flanagan]

Congratulations and great picture of your kids. I see one of them has a comedic flair. They'll remember stuff like this when they're older. I know I do. I'd give anything to have my Dad back.

Are there broken rings on that piston? Hard to tell with all the sludge.

[RobertKB]

Congratualtions! It is nice you are working with your son as well as mentioned before. I bet he was as excited as you were. What are the future plans now for the engine?

[greg g]

That will buff right out................Your boys look like thay just pulled a big bass out of the lake!!! Now that you can rotate the engine, crank it around and watch for any valves that aren't moving. When you spot one, give it shot of your medicated goo and then play whack a mole with the rubber mallet.

[JoelOkie]

That's funny, because after I saw that pic of those boys with the piston over on the truck side I was sooooo tickled that I had to have my wife look at it too......told her..."don't they look like they just caught a 10 lb. bass" She enjoyed it also. I especially like the little dead pan guy with the pointer. The pic is great. It sure made our day. Joel