Help troubleshooting miss at all rpms

removing the intake and checking valve clearance would definitely give you a lot of information sounds like its typical parked flathead todays fuel is basically dry[alcohol] and has little to no lubricity hence hich valve wear where as the fuel from the time of the flathead was oil based so high lubricity that's why i run a small amount of 2 stroke oil [same as your outboard or chainsaw ] in the fuel about 50cc to around 50 liters of high grade fuel This lubricates the valve stems and stops them from hanging up when left standing . I would try using a penetrating type oil [MMO] in a fuel mix and just run 2/3 tankfulls thru the engine just might clear it up and it wont cause any more hurt if it doesn't
 
Just before I changed the engine in my '51, it had compression numbers like yours; maybe a bit better. It started and ran smoothly, but had no power. It sounds like your engine is just plain worn out. It shouldn't be shaking, etc. like you describe. You can probably chase down the problem that you are experiencing, but even then, you will end up with an engine that is way down on power with a short life expectation.

Face it; it's probably going to need some serious attention soon.
 
tubman said:
Just before I changed the engine in my '51, it had compression numbers like yours; maybe a bit better. It started and ran smoothly, but had no power. It sounds like your engine is just plain worn out. It shouldn't be shaking, etc. like you describe. You can probably chase down the problem that you are experiencing, but even then, you will end up with an engine that is way down on power with a short life expectation.

Face it; it's probably going to need some serious attention soon.
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Agree. Sounds like this puppy is just plain wore out. Sorry, OP
 
A vacuum gage can tell you a lot. As noted there's specific symptoms the gauge shows like a fluttering needle which indicates a sticky valve. At purchase mine had a sticky valve. I put in a light weight oil in with a quart of good old Marvel Mystery oil. The problem went away very shortly. One needs to run these engines once in a while; they love it.
 
Thanks everyone for the help. I know she'll need a proper rebuild at some point. however, i'd love to at least get a summer out of her this year if I can. it won't see many miles anyhow. I'm thinking try some mmo and see what happens. after that, pull heads and maybe an in-chassis valve job. like most of us, I have a family and don't want to sink too much money into a 4door car that i'll never get back. it's not a sentimental car. I'm not opposed to a farmers rebuild either - dingle hone, rings, valve job, and regasket. keeping her on the road is better than letting it sit.
 
Sounds like a plan. When I was a cash-strapped college kid, I did about the same thing to the '52 I was driving to school. I flat wore out a rental stone hone getting the cylinders close enough to accept a couple of junkyard pistons, added a set of rings from Sears, touched up the valves, and put it back together. It served me well for a couple of more years, and in fact, was running well enough that I sold it to a friend as a driver for his little brother.

It's not what I'd do these days, but it worked. As I remember, the block had a couple of cracks between the cylinders and valve pockets; I shrugged my shoulders, added a bottle of Barr's Leaks, and never had a bit of trouble with overheating.
 
Hoodooman said:
Thanks everyone for the help. I know she'll need a proper rebuild at some point. however, i'd love to at least get a summer out of her this year if I can. it won't see many miles anyhow. I'm thinking try some mmo and see what happens. after that, pull heads and maybe an in-chassis valve job. like most of us, I have a family and don't want to sink too much money into a 4door car that i'll never get back. it's not a sentimental car. I'm not opposed to a farmers rebuild either - dingle hone, rings, valve job, and regasket. keeping her on the road is better than letting it sit.
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Perfect plan. Seafoam and MMO and just keep running it. Hopefully it will free some things up.
 
If it comes down to trying an in-chassis valve job, can anyone recommend a stone/pilot kit etc. for me to dress the seats, if they're pitted, which is likely? I figure dress the seats as lightly as possible to smooth out the pitting and either new valves and one piece guides or lap the old valves if they're not burnt. Thanks. I know there's more guys here that've done old school valve jobs to keep these cars running. Appreciate it!
 
Seems like MMO in my gas and putting a couple hundred miles on helped a lot. She's running pretty good now! Still old and tired but very drivable for now. We'll see how long she lasts like this. Thanks everyone.
 
Good to hear! I've only been into these flatheads the last four years and I love them. Have resurrected 3 engines that sat for years, and they all got better just driving them.

My 54 Meteor (Canadian Ford - last year of the Flatheads for us) I've put over 12k miles on it since I bought it in June of 2021. I love that car and the simplicity of the engine vs anything modern.

The tricks others mentioned about using 2 stroke oil in the fuel, and MMO are both things that I did and still do if an engine has sat, even over the winter.
 
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