Oil Out Breathers
 

Does Every Body Have This Problem Of Oil Puking Out There Breathers...

Re: Oil Out Breathers
 

I would get rid of those push on breathers and run a hose up to the flame arrestor.

I had the same problem with my Scarab with the push on breathers. I went out and got the push-on breathers with the hose attachment and ran braided line up to the flame arrestor.

Re: Oil Out Breathers
 

That Is What I Was Thinking But I Hate To Give The Motor More Hot Air Would A Puke Thank With A Breather Be Better

Re: Oil Out Breathers
 

Are you also running a pcv valve or just the breathers. The intake can be drilled and taped for a pcv valve under the carb flange if the lifter valley tray is in place and that will solve your problem.

Re: Oil Out Breathers
 

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

Re: Oil Out Breathers
 

What kind of power, you may not need to worry about it. My motors were 550 hp 502's.

Re: Oil Out Breathers
 

Is the oil puking out of both breathers or only the port side? I would try to put both breathers up in front of the covers, that helps this problem. I have no pcv and no tubes to the flame arrestor with no oil puking problems at all.

Re: Oil Out Breathers
 

Wonder if it's the nature of push on's? Mine stay almost 100% clean.

Every once and a while I wipe a little oil off the cover from around the base but I think some oil is very much expected, especially with any amount of power.

Both of mine are towards the rear as you can kind of see in the pic.

Re: Oil Out Breathers
 

Could be.

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

Re: Oil Out Breathers
 

What oil are you using? I had the same problen on mine, I was using Mobil one syn. when I switched back to Reg. Mercruiser oil it stoped?

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
 

:stupid:

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
 

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
 

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
 

And they are sooo much prettier too! :evilb:

Re: Oil Out Breathers
 

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
 

Top rings,Smitty