engine builders come in
Thread Starter
Melting Slicks
Joined: Jul 2006
Posts: 2,373
Likes: 6
From: Baltimore MD
engine builders come in
Guys ive been haveing a problem for a little while now,im burning oil ,engine runs good,but burning oil especially at full throttle ,at idle it doesnt smoke,only at full throttle. so i took the engine a part because im also putting a 5 speed in.what i found wassmall puddle of oil in the intake runners ,laying on top of closed intake valve.I had loosen up the rockers and it sat for a couple days,i then went out to pull the heads and then i looked inside the intake runner and found the small ,small puddle of oil laying in there on top of valve.My thought is that maybe it came from the valve seals,maybe leaking.I did put high heat silicone on the threads of the rocker studs that are at the intake side,so i dont think it is that.Another one might be that the intake gasket might not be sealed good,i checked that and it seems to be a good seal.These are the only things i can think of that cane do this,what do you think it is? If the rings werent seated then both intake and exhaust valves would be carbined up on the piston side , right? The heads are new afr 210s,could the seals be leaking? Im kinda stumped. Bill
Pro
Joined: Nov 2010
Posts: 602
Likes: 32
From: Old Bridge, NJ
I'd look at your ventilation as well. I'm looking into this for my car. Mine burns oil on heavy acceleration. I currently only have a PCV valve going into the base of the carb. I realized that I have nowhere for air to come in and flow through the crankcase. I have Chevrolet Performance valve covers without baffles, so I suspect that the problem is twofold:
1. oil getting into intake runners through PCV
2. Too much pressure building up under acceleration and nowhere to vent fast enough
I am considering using a catch can to avoid any possibility of spewing oil onto the engine/headers.
1. oil getting into intake runners through PCV
2. Too much pressure building up under acceleration and nowhere to vent fast enough
I am considering using a catch can to avoid any possibility of spewing oil onto the engine/headers.
Thread Starter
Melting Slicks
Joined: Jul 2006
Posts: 2,373
Likes: 6
From: Baltimore MD
Thread Starter
Melting Slicks
Joined: Jul 2006
Posts: 2,373
Likes: 6
From: Baltimore MD
Ive tried different ways with one and two pcvs,then 2 vented breathers,no breathers,didnt make any difference.What can cause oil to lay on top of those closed intake valves? I did have one cylinder that was dry.Now i am looking at the valves through the intake runners and the valves are closed.
Last edited by Billysvette; Jun 4, 2012 at 10:47 PM.
Le Mans Master
Joined: Aug 2010
Posts: 9,272
Likes: 17
I vote, your right on the rings, if it was coming thru the rings your plugs would be wet, and it would blow out the exhaust with out leaving puddles. but then that applies to the rest also,, do your valve covers have baffles? what oil pressure are you running? oil on top of valves , with no baffles, yes. with baffles , valve guides /seals. also could just be a bad pvc, no likely but possible
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Team Owner
Joined: Apr 1999
Posts: 21,953
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From: Reno Nevada
2024 C3 of the Year Finalist- Modified
I had a fresh motor with brand new AFR 210's Within 1500 miles it started smoking. By 2500 I was embarraced to drive it. AFR oil return sucks and the valve guides are swimming in oil. So I jst changed out the crappy AFR seals with Vintons. Problem cured. Later when I took the heads off I machined a slott outboard of the springs and contoured the drain back areas so the oil returns from the heads.
It takes lots of miles for the rings to ware out
It takes lots of miles for the rings to ware out
Last edited by gkull; Jun 5, 2012 at 04:27 PM.
Thread Starter
Melting Slicks
Joined: Jul 2006
Posts: 2,373
Likes: 6
From: Baltimore MD
I vote, your right on the rings, if it was coming thru the rings your plugs would be wet, and it would blow out the exhaust with out leaving puddles. but then that applies to the rest also,, do your valve covers have baffles? what oil pressure are you running? oil on top of valves , with no baffles, yes. with baffles , valve guides /seals. also could just be a bad pvc, no likely but possible
High volume oil pump,puts out 80 psi cold and about 40 to 50 warm.Ive also tried different pvcs.Im thinking seals ,but these are new afr heads ,usually they have top quality.
Thread Starter
Melting Slicks
Joined: Jul 2006
Posts: 2,373
Likes: 6
From: Baltimore MD
I had a fresh motor with brand new ZFR 210's Within 1500 miles it started smoking. By 2500 I was embarraced to drive it. AFR oil return sucks and the valve guides are swimming in oil. So I jst changed out the crappy AFR seals with Vintons. Problem cured. Later when I took the heads off I machined a slott outboard of the springs and contoured the drain back areas so the oil returns from the heads.
It takes lots of miles for the rings to ware out
It takes lots of miles for the rings to ware out
Thread Starter
Melting Slicks
Joined: Jul 2006
Posts: 2,373
Likes: 6
From: Baltimore MD
Yea i thought about them too,but i could not see anywhere where the gaskets were leaking.Looked to be a good seal all the way around,but i am going to try and different intake gasket this time around.I used felpro 1206.
Thread Starter
Melting Slicks
Joined: Jul 2006
Posts: 2,373
Likes: 6
From: Baltimore MD
Guys i found out that afr heads come with viton valve seals,so now im puzzled again.i dont think its them.Now maybe its the rocker studs leakingor intake gasket .i did use high temp silicone on the rocker studs,maybe not enough,i dont know.The intake gasket,if it was leaking would leave oil on top of valves wouldnt it? does anybody know of a good intake gasket that really seals good?
Race Director
Joined: May 2005
Posts: 10,674
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From: Millington Illinois
St. Jude Donor '08-'09
You have a blower right? My guess is your forcing pressure past the rings, crankcase pressure is building and that pressure is forcing oil past your valve seals, intake gasket or pressurizing the PCV causing mist to enter the intake. I would do a leakdown test on it.
Race Director
Joined: May 2005
Posts: 10,674
Likes: 122
From: Millington Illinois
St. Jude Donor '08-'09
Le Mans Master
Joined: Apr 2007
Posts: 7,353
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From: Graceland in a Not Correctly Restored Stingray
Might should check crankcase pressures too while you're at it.
Thread Starter
Melting Slicks
Joined: Jul 2006
Posts: 2,373
Likes: 6
From: Baltimore MD
Mako its all apart right now,im going to redo the engine and im putting in a 5 speed trans.The only clues i have is that theres oil laying on top of the intake valves.