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Re: Oil Out Breathers

nocigarette that motor shouldn't have a lot of blowby if its a fresh engine!
i have read that oil in the combustion chamber increases the likelyhood of detonation, i would never run a hose from the valve cover breather to the carb on a high perf marine engine to introduce oil mist into the intake tract. laz what are your thoughts on this? or any of you other engine guys

Re: Oil Out Breathers

How about baffled grommets? Seemed to slow down / stop the oil seepage coming from my oil breathers. My next step would be been the puke tank if needed.

Re: Oil Out Breathers

Quote:

Originally Posted by ratman

I'd say it all depends on the power.

I ran 500 hrs on my old motors, no detonation. I wouldn't do it on my blower motors though. Also, unless you vent the hose outside the boat that oil mist gets sucked into the motor anyway because the bildge is in a somewhat enclosed area.

I'm curious what the builders have to say as well?

Re: Oil Out Breathers

Quote:

Originally Posted by articfriends

I had this problem with my 502 blower motor because of blowby from the rings/high leakdown. I sealed up the breathers with tubes to a puke tank with a vent on the puke tank and it pushed oil out the seals on motor. I now use extended breather tubes with baffles in them and zero gap rings. Leakdown is less than 10 % where 502 was 25 plus on some cylinders and the taller breather tubes keep what blowby I do get from letting as much oil drip in engine compt,Smitty

Smitty,

Please elaborate on th parts req'd: pistons, rings, etc. So far only my dipstick pushes out on sustained high speed runs-no oil anywhere (502 Whipple/mpi).

Regards,

Mark S.

Re: Oil Out Breathers

you guys are awsome i found out today that one breather at the front and one at the back is a bad idea, plus my covers are too low and the breathers were lined up with the throw of the oil of the rocker. New valve covers ordered with breathers at the front and taller stacks........

Re: Oil Out Breathers

Quote:

Originally Posted by Panther

Could be.

I now have similar valve covers and breathers as you do and I don't have any oil problems.

And they are sooo much prettier too! :evilb:

Re: Oil Out Breathers

Quote:

Originally Posted by Breathe Later

Smitty,

Please elaborate on th parts req'd: pistons, rings, etc. So far only my dipstick pushes out on sustained high speed runs-no oil anywhere (502 Whipple/mpi).

Regards,

Mark S.

Stock bore 502 pistons have fairly low tension metric rings,they tend to get blow by and high leakdown especially with a supercharger.When I still had a 502 I bought 4.470 bore j/e srp pistons that could be installed with some serious honing with a tq plate that used std american size rings,motor had decent leakdown at 100 hours but by 150 was venting like crazy out breathers,by 170 hrs right before I pulled it out to rebuild it it was leaking out every seal in motor and pushing oil out dipstick tube because leakdown was terrible. When I built 540 I used zero gap rings,had great leakdown and ring seal even at 125-130 hours when I pulled it out to freshen and upgrade. I also used ring seat compound to help rings seat faster which really worked good.Currently 540 has around 50 hours on it with no considerable blowby running 9-11 psi boost. Some guys have tried to tell me zero gap rings don't work but I wouldn't have a blower motor without them,Smitty

Re: Oil Out Breathers

smitty r u running 2nd ring gapless rings? thx

Re: Oil Out Breathers

Quote:

Originally Posted by ratman

smitty r u running 2nd ring gapless rings? thx

Top rings,Smitty