No compression

[Al 29Tudor]

We just had a club members 29 coupe like that. The compression was all over the place and varied from test to test. Some days it was ok then some days it wouldn't start. Finally we took the head off and them the side cover and what a mess. All the ports, valve stems and guides were coated with a thick layer of carbon goo like molasses. We removed the valves, guides and cleaned everything including the ports. Then lapped the valves reinstalled everything and it purred like a kitten as they say.
Al

[Tom Wesenberg]

I would clean the gas tank with Marine Clean to get rid of the old tank liner. Try to only buy gas without ethanol and use 4 ounces of Marvel Mystery Oil with each 10 gallons of gas. I'd also put a can of Sea Foam in the oil.


E-85 might strip off the old tank liner. I used a gallon of E-85 and a hand full of lag bolts and wood screws, then rotated my Studebaker gas tank at 45 degrees for an hours, then flipped the tank over and repeated for another hour. My tank was spotless clean inside, so I have no idea why anyone would have lined the tank in the first place. I would never line any tank.


BTW, since the head is off, start by spraying Kroil on all the valve stems to free them up.

[Marshall V. Daut]

In the 1980's when gasoline just started going south in quality, the BIG thing in the Model A clubs was to pour some magic elixir into the tanks to seal them. I'm not sure what the connection between antique car gas tanks and new blends of fuel was, but everybody and his brother were sealing their gas tanks. The idea smelled fishy to me, so I steadfastly refused to do that to my cars or friends'/customers' Model A's who had heard or read that this was the thing to do. I was concerned about down the line in a few years that whatever the Feds were calling gasoline might breakdown what worked well in 1980. I am no clairvoyant or wise man able to see into the future, but my gut feeling was: "Don't do it! You'll be sorry! Better living doesn't always come through chemistry!"
Well, the absolute garbage that's being passed off now as fuel for our cars is proving itself to be highly detrimental to rubber parts in the fuel system and to any older tank sealers that can't stand up to the new blends. We already know how Ethanol almost turns into corn syrup if left too long in a fuel system. I wonder if the OP's problem can't be traced back to old fuel that broke down and an older sealer letting loose? To have that much gooey crud inside the engine doesn't come from just one bad tank of gas. It had to have been accumulative. I should think that when the OP pulled off the cylinder head, there should have been one heck of a gooey mess. That would have been a sure sign that there's more of that stuff inside the engine, too.
Well, I'm sure we're all glad that the OP found the problem. Whether one person or everyone supplied the right answer doesn't matter. All the answers are things worth checking in case of future problems of similar nature among the readers. Good information for all of us to digest and store away for a rainy day.
Marshall

[Tom Wesenberg]

Good thought Marshall. The carb will also need to be cleaned out.

[40 Deluxe]

Originally Posted by egm

Tom, found out thank was sealed 25 year's ago I think it's coming off now what a mess.

25 years ago tank sealers were sourced from the light aircraft repair industry so not compatible with gasoline that has been contaminated with ethanol. Ethanol dissolves the sealer, causing nasty problems like you're seeing.
Try to find stations that sell pure gasoline, perhaps at a marina. Using ethanol in a boat is another recipe for disaster!

[eagle]

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I used some of the white tank sealer 20 years ago on a couple old stationary engine gas tanks that were so full of holes it was hopeless to try to repair them. They have had gas in them continuously, some sitting for years unused, and they have stayed perfectly leak-free and no gumminess. However, I got some red tank sealer from Napa later and that stuff was junk. Turned to GOO in a couple years.

[Ggmac]

Is there any dood tank sealer ? Sorry to hijack but I'm at crossroads and either try to repair or replace .
Thanks