• If you log in, the ads disappear in the forum and gallery. If you need help logging in or getting registered, send request to: webmaster@southernairboat.com

540 new cylinders


Well-known member
I just put 6 cylinders on my 540, I think I did it right, sent mine to jurnigans, I just ran the boat today for mabe 30 minutes. I noticed blue smoke while on the trailer and while running it up, new to aircraft motors, I hope the rings need some time, I have built a few hot rod motors and don't remember any oil smoke. can some one tell me if this might be the norm or do I start over. thanks again, Mike
Most new aircraft cylinders take a while to break in. I have seen some take as much as 50 hours plus to stop burning oil. Yo9u just need to run it and keep an eye on the oil level.

Someone else may jump in here but make sure you are running the correct oil as well. I don't know if that is mineral or detergent on just cylinders. I was told by Jr. to run the mineral for about 30 hours or so. But I had the whole motor rebuilt.
Run non-detergent oil for 50 hours. Find an overhaul manual and see what they recommend for oil and run in hours. I allways try to get folks to vary the engine RPMs the first 3 hours.
Mike, My 520 Continental did not smoke during the frist run after engine build or during break in. My friends fuel injected 540 smoked black at idle and oil fouled the bottom plugs a couple times after rebuild during break in.

I ran Areoshell during break in and and changed oil every ride until I had 20 hours on the motor. That's probably more oil changes than was necessary. I still run Aeroshell.
Are you cylinders crome, or steel?
If there steel barrels, youall have crome rings,,,which are very hard, and take awhile to seat. You might do a plug check to see if its all, or just 1 cylinder using oil. If its one, call Jr.
Dont know what shape your barrles are in, new crome, boared or?
Just re-ring etc. Why did ya take them off?
my cylinders all have the orange strip and my rings are steel,also I shot a couple of squirts of mineral oil in each barrel before starting. oil still ok on the stick.
with the freash top end, will my rpm be down till things loosen up, i seem to be stuck at 2500, where as the motor use to see 27oo with the current pitch. motor still has less than 2 hrs
Mike, it'll take a few hours ...... don't lean on it too hard.
Sounds to me like Bro. Jurnigan built you a nice set of cylinders. If, after 40 hours, it doesn't want to turn 2700 again, we'll look for something else.