blowing oil out of breather cap

[edj1993]

I recently purchased a'63 Super 88 with what I believe is the 394 hi-comp. The motor was supposedly "rebuilt" recently. It runs beautifully but I am getting oil blowing from the breather cap at the front of the engine. There seems to be a fair amount of blowby coming from the breather but I am not sure what's normal. Also, I have looked at pics of other 394's of this vintage and noticed tht the breather tube comes up at an angle-mine comes straight up(90 degrees). I dont really want to tear into the engine yet.. Is there something I am missing ??

[rocketraider]

Second that. It was a known problem after those engines got some miles on them. From what I've read a lot of it traced back to valve guides.

What's your oil consumption? When my blue 64 was running, it blew oil vapor all over the place but used only a quart every 1000 miles or so- definitely not enough to make me tear into it.

I think a lot of it is because of that weird PCV valve the 63-5 cars used. Cars I've seen with California semi-closed PCV generally don't fog as badly.

[edj1993]

Thanks, guys; however, this is more than just blow-by.. It is coating the whole engine compartment with oil, and it pools in the valleys at the base of the breather cap, intake manifold, etc.. The hood insulation is also pretty saturated. Also, any ideas on the angle of the breather tube as mentioned above.

[rocketraider]

Is the foam filter in place in the oil fill cap? If it's blowing oil as bad as you say it would soon saturate that, though.

I'd check the oil drainbacks in the heads just in case it's pooling in the rocker area and sucking in around valve guides.

Have you done a compression check? If it was in fact rebuilt, sounds like either rings have not seated or one is cracked.

Is the PCV flapper valve functioning? Take it loose and shake it; if it rattles it's probably OK, but I still think they're weird. Make sure the small vacuum line isn't plugged.

Wouldn't worry too much about the oil fill tube angle. Most I've seen angle off to the right side of the car, but my green Starfire has aftermarket A/C which required a modified fill tube. It's bent like a dogleg and I'm pretty sure came with the A/C installation kit.

[edj1993]

Thanks Rocketraider.. The small vacuum line is not hooked up-would that make a difference ? If so, should this be hookd into the carb ". This car has the factory A/C so maybe that's why the breather tube is straight up. The breather cap has the steel wool type stuff in the top. I have even tried stuffing a plastic scrubber thing into the tube, but it still comes out.. I have not had the valve covers off so dont know bout the oil drain tubes.. I am going to run a comression test next.. thanks for your input.

[rocketraider]

The small vac line goes from the PCV valve to the back of the carb, or some years there's a vacuum port on the intake. It will affect it some because the PCV relies on that small amount of vacuum to help lift the flap off its seat as well as pulling some of the blowby gas back into the engine for reburn. Without it, the engine is not getting enough fresh air in via the aircleaner tube, and not allowing vapors to be sucked out of the valve cover and into the carb via that same tube.

The damn thing is just weird, but it apparently worked for a couple years until they decided to use a more conventional PCV system.

Hope hooking the PCV vacuum back up helps. It sure can't hurt.

[frdmftr]

Also look at the valve covers themselves. The stock covers have a shield inside to 'help' keep oil blow at a minimum. I have aftermarket Edelbrock's and sure'nuf, they don't have the plates.

I get minimal fogging, carry roll of shop towels in trunk and a ziploc to store soiled ones in.

[Jokers69]

I have aftermarket Edelbrock's and sure'nuf, they don't have the plates.

My Moroso valve covers have baffle plates in them, so I ran one of the chrome caps with the PVC valve built in.

[frdmftr]

Good suggestion. I will convert mine as well. Anything helps.