Excessive Oil From Valve Cover Breathers

[Virgil]

427 Aluminum Shelby motor (497ci) with Shelby heads and rockers. It seems maybe that there's too much crankcase pressure? Has an excessive amnount of oil from V/C breathers as well as the puke tank vent tube. Any thoughts or comments? (Everthing else is fine and runs great.)

[saltytri]

I stuffed a chunk of air filter foam in the fill neck. No more oil comes out of the breather. Cheap and easy.

[Burnd]

You're giving limited very information. I'm a little confused; what's the correlation between the puke tank and crank case??? I know one thing; if you have oil blow-by, in a coolant puke tank, in a spanking new Shelby aluminum block; this is going to get reaaaaaally interesting.

That being said; you got a biggun in c.i.d. there; do you have all 3 breathers on the motor?; i.e. 3rd breather on the manifold?; pcv?c, etc. Rings seated yet? Any smoke on start up; if so, what color? I'm not sure about aluminum aftermarket blocks, but if you have 2 restrictors in the back of the oil galley feeding the cam like a real 427 and they are the wrong size, it will create pressure issues; if you have Comp Cams lifters they may be the wrong ones. They shipped out tons of them in the wrong boxes last year and they are still in circulation. They are 460"s and unfortunately they fit in the 427 lifter bore (and they work) but you will fill the valve covers with oil and have a boat load of crank case pressure. It would be nice for them to consider doing a recall, but that's too smart. On mine, the breathers blew off the VC'wrs and they just richoted around in the engine bay like a grenade (serious CC pressure). You sure it's CC pressure and not $hity breathers with no baffling or brillo? Is your dip stick (the one on the motor) creeping "up" and out of the tube after you wind it up? Wrong spring in the oil pump will contribute to excessive CC pressure. Blow-by in a cylinder will do it too. Is it running hot?? Any bubbles on the dip stick? Who built the motor? You only have 2 posts, so I assume the motor and you are new?? You should give these guys here a little more information or beat on the mechanic that built the motor for you. That motor's not a cheap date with the block and heads; although the block is notorious for being a headache until you get the bugs out of it. There is a higher percentage of real motor heads on the FE forum, if you can't get it answered here. They're just not Cobra guys. But if I paid someone, what you paid someone to build that motor; I would be leaning on him reaaaaaaaaaally hard to solve my problem. I HATE leaks.

Bernie

[427SnakeSC]

Originally Posted by saltytri

I stuffed a chunk of air filter foam in the fill neck. No more oil comes out of the breather. Cheap and easy.

That's using the K.I.S.S. rule of thumb!

[Virgil]

Wow, thanks for all that information! Yes, me and the motor are both new.
I do have comp cams lifters (and cam for that matter.) Puke tank reference was to the tank on the firewall that connects to the rear of intake manifold.
Just one breather through the vent on the rear overflow (puke) tank. I had V/C breathers in place and they were venting a lot of oil. Also get blow-by up through the distributor shaft hole. Rings seated - no smoke. Restrictors in place but not sure of size. Dip stick seems to stay in place. Runs cool as a clam. Dude's gone that built motor. Thanks again for your response. -- Virgil