racinfever

Recently after changing my engines over to a blower set up, I ran the motors a little on the rich side of tuning during break in. After 25 hours of break in, I switched to synthetic oil "Mercury 25/40 syn. blend". I ran a poker run approximately 140 miles - each motor used 4 quarts of oil. After the poker run, I switched back to conventional "Mercury Oil 25/40". Oil consumption slowed to about a quart a day. I then changed jets to leaner tune-up but I'm still using oil. I'm hoping with the leaner tune-up and switching to 20/50 oil, ring seal will improve. There is no excessive blow by and leak down test still good. Will my ring seal come back??? Let me know your thoughts!! One last note, there was no oil consumption during the 25 hour break in period!!

HighPriority

That does not sound good to me. 25 hours of break in is a ton, we break in new motors for about 15 to 30 mins. before changing to synthetic motor oil.

Maybe some of the engine guys will be able to help you, best of luck.

stevesxm

what convinces you its rings ? not doubting you but 4 quarts in 140 miles would leave a lot of oil on the plugs.... you didn't by any chance run some giant clearences because of the blower and running the motor really cold , are you ?

if you are right and it is the ring seal, a leak down will tell you that in no uncertain terms. if it IS ring seal and the bores are glazed up, i think its got to come out.

oh... and if the 2nd rings got put in upside down it will do that as well...

racinfever

Is it possible that the Merc. Synthetic oil was low in viscosity and didn't agree with the motor temperature and clearances? And now needs to be washed away by conventional oil!

Griff

Uh...........NO.

Do a leak down. 4 quarts in 140 miles is nuts. I'm guessing thats about 2-3hrs. 1 quart in 10 hrs should be about the max amount of oil used. You're using more than 10 times that.

B one

You need to go to a lighter oil not a heavier oil. Going to a lighter oil should help bring your rings back around. The rings are working extra hard trying to wipe the heavier oil of the cylinder walls. The rings are not wiping all of the oil off the wall so it is going out the exhaust. Use a lighter oil and and the rings will be able to wipe the cylinders clean and oil consumption goes down.

racinfever

I agree the lighter oil is easyer for the rings to wipe oil away,
but how light can i go? I am curently using mercs 25/40.
The motor is a supercharged 565.
remenber no oil consumption until i tried the syn. oil

B one

Try a 10w30 your rings are not hurt yet. Try this lighter oil it should help.