My 52 has been sitting a while,got it running,runs and idles pretty smooth except for an occasional "pop ",which may be a valve trying to stick.Any ideas? I am afraid to put any thing in the oil as it may also free up some 60 year old sludge,with disasterous results,and do not plan to do a engine tear down soon.Thanks for the input.

 

What do you know of the engine's history? By now, it's rare to find an engine that hasn't been running on high-detergent oil for at least 40 years. Any built up sludge should be out of it by now, IF the engine has been in regular use.

I'd pull off the intake manifold, which is a pretty easy job. No draining of antifreeze. Just removing the generator and fan, the carb, and disconnecting some stuff. Looking in the lifter valley will give you a good idea of how much sludge is in the engine. And you can perhaps identify the culprit valve, spray some SeaFoam or other light oil on the stem and guide, to free it up. If it's really sludgy, you can clean it out.

Usually tho, I've found sticking valves/lifters to be the result of varnished oil. Running some SeaFoam in the oil for 100 miles of full-temperature operation is often successful.

 

Truck had sat 20 years when i ended up with it,and i believe had sat some prior to that.The odometer shows 73,000,and appears to be original and to have never been in to.The oil is super nasty and needs changed.I replaced the fuel pump and there was the usual sludge around the push rod and in the general area.it might loosen up with a oil change and running.Thanks for the ideas.I have several years of mechanic experience,but none with flathead engines.

 

Oil change, full tune up and a good driving may do wonders. The flathead is no different than any other engine other than configuration and years of technology improvements.

 

If it doesn't come out of it with an oil change and some driving, I would pull the intake as Ross suggests. You can do a lot of valve train inspection and cleaning just by removing the intake.

 

Thanks fellas,i am going to change the oil and run it some next couple of weeks.

 

That's good advice for all of us!!

 

That's helpful to me as well. Been running mine a couple of weeks and I think I've got one stuck. Will try the seafoam trick and see if that might be the ticket.

 

I have used the Transmission Fluid down the carb trick while running it. Just pour a small amount in while working the throttle linkage to keep it running. It has worked for me a couple of times on different cars. It will smoke, but does free up valves. Drive it a short while after and the smoke will stop/burn off.

Then run it with a heavy does of Marvel Mistery Oil in the gas and oil.

I have used this trick on my flathead trucks and model a's.

 

One day my 289 suddenly developed a nasty clacking noise. I put a quart of atf in the crank case and it freed the valve in less than five minutes. The oil was very dirty when the clacking started, and I believe that this was the cause in the first place. After the clacking stopped, I changed the oil and never had a repeat of the problem. I know that alot of people say don't use atf or any other high detergent in the oil because it might cause some gook to come loose and plug a galley. Well, when would be a better time for the gook to come loose? When your 100 miles from home and least expecting it? Good luck, and let us know how it turns out. There are a lot of lurkers out there that may have the same problem. Jag

 

Good call on the MMO. Find a MMO, Schaler, or Ampco oiler and you don't have to mess with adding it to the gas.

 

My fire truck needs some help. This is what is runs like. Ps I am not the one working the throttle,it was the guy selling the truck
I noticed smoke coming out the back breather

 

MMO is worth a try for stuck or varnished engine innards. Run a quart of it in place of a quart of regular motor oil in the crankcase and, approx. 4 oz per 10 gallons of fuel.