building crank case pressure
Thread Starter
Racer
Joined: Aug 2003
Posts: 281
Likes: 0
From: overworld
building crank case pressure
ok well it seems that my engine is building too much crank case pressure. i have a PCV thats is working on the pass side and a breather on the drivers side. its a fancy little peice that vents out the bottom instead of all around. like a mini air filter. im getting oil leaking out the oil fill cap. only a little and only after driving it for a little while. some times the oil dipstick isnt seated all the way down after a drive either. so i figure im building pressure.
the valve covers are new as is the oil cap. its got a good seal and sits down snuggly too. the engine is a .030 over 350 will edlebrock performer heads and a performer intake. the cam is an elgin comparable to the one edlebrock supplies in its performer package. its nothing radical as i have to operate the headlights.
before i put the breather on the pressure actually built up enough to blow the intake seal on the back side out. now it only leaks out the cap a little after a little while of driving. but it shouldnt be doing this even.
so whats causing this to happen? the engines not that radical to need anything fancy like a vacum pump. and everything runs very well. so what should i be looking at to determine whats causing the pressure build up? thanks
the valve covers are new as is the oil cap. its got a good seal and sits down snuggly too. the engine is a .030 over 350 will edlebrock performer heads and a performer intake. the cam is an elgin comparable to the one edlebrock supplies in its performer package. its nothing radical as i have to operate the headlights.
before i put the breather on the pressure actually built up enough to blow the intake seal on the back side out. now it only leaks out the cap a little after a little while of driving. but it shouldnt be doing this even.
so whats causing this to happen? the engines not that radical to need anything fancy like a vacum pump. and everything runs very well. so what should i be looking at to determine whats causing the pressure build up? thanks
Melting Slicks
Joined: Jun 2002
Posts: 2,844
Likes: 99
From: Orrtanna Pa.
Re: building crank case pressure (Ram Air Formula)
Assuming the oil looks OK and there's no evidence of bubbles in the anti freeze,how's the PCV valve hooked up? Can you feel any suction with the PCV valve out of the valve cover with the engine running?
Safety Car
Joined: Jan 2001
Posts: 4,660
Likes: 3
From: South Central Louisiana
St. Jude Contributor
Re: building crank case pressure (Ram Air Formula)
I was having problems with oil leaking from my breather cap and oil fouling my plugs from oil vapor entering the intake through the PCV. I am currently trying a different approach, but I will wait to see what others suggest.
Team Owner
Joined: Jul 1999
Posts: 65,492
Likes: 230
From: Orange Park Florida
Re: building crank case pressure (Ram Air Formula)
IF you ever find out what causes that, lemme know....
I managed to move my PCV valve input from the air plenum of the TPI to the factory original setup, leading into the floorboard of every individual port of the intake tract in the manifold.....and somehow it's seemed to help in the oiling situation, both on the valve covers, and in the intake tracts...of course...it's downstream now....engine seems to NOT burn oil,....but it used to allways leak out the valve covers both from the PVC valve rubber fitting and the pass side that went to the throttle body before the blades....
to me it should make NO differances at all....but it does, somehow...
I have had engines do this from time to time, and last forever while doing it...seems the only oil losses are from top side leaking....or blowing oil out the breather caps....sometimes in spite of all baffels or attempts to stop it....
other engines don't do it at all, .....can't beleive I have been SO unlucky the majority of my engines have had the problem....rebuilt or factory stock....
wanna see an oiley mess??? look at a Miusubitchy engine with a few miles on it.....you'd think the crank case was sealed with NO breather of any type, as oil comes from every pore in that engine...amazing...
GENE
I managed to move my PCV valve input from the air plenum of the TPI to the factory original setup, leading into the floorboard of every individual port of the intake tract in the manifold.....and somehow it's seemed to help in the oiling situation, both on the valve covers, and in the intake tracts...of course...it's downstream now....engine seems to NOT burn oil,....but it used to allways leak out the valve covers both from the PVC valve rubber fitting and the pass side that went to the throttle body before the blades....
to me it should make NO differances at all....but it does, somehow...
I have had engines do this from time to time, and last forever while doing it...seems the only oil losses are from top side leaking....or blowing oil out the breather caps....sometimes in spite of all baffels or attempts to stop it....
other engines don't do it at all, .....can't beleive I have been SO unlucky the majority of my engines have had the problem....rebuilt or factory stock....
wanna see an oiley mess??? look at a Miusubitchy engine with a few miles on it.....you'd think the crank case was sealed with NO breather of any type, as oil comes from every pore in that engine...amazing...
GENE
Race Director
Joined: Oct 2000
Posts: 15,037
Likes: 79
From: central FL, near the beach.
Re: building crank case pressure (Ram Air Formula)
i got my 67 galaxie in 1985 cheap because it blew out oil and needed a rebuild. i re-routed the breather to draw from inside the air cleaner. (relieves crankcase pressure)
it's been dry ever since.
never rebuilt with 128,000 :cheers:
it's been dry ever since.
never rebuilt with 128,000 :cheers:
