Kubs

I was at a track day in my '90 over the weekend at Nelson Ledges and on my first few laps around I was black flagged. I was told I was smoking going around the left hander back into the carousel. I popped the hood and looked and looked and the block and everything was dry. I found someone who was following me and they said it was coming out the exhaust!! But only in one spot of the track. I remember reading on here that the C4 PCV system tends to suck in oil from the passenger valve cover. I pulled the hose off the throttle body and sure enough there was oil in it. Well I didnt want to go home in the AM so thinking quick I took a bottle of gatorade and rigged it up with duct tape to act as a catch can. While it looks very hoaky it kept me running all day without any issues!



Now I need to find some good baffled valve covers in which I can put the gromets on both sides facing towards the front of the car. If it exists I would like to find covers with threads for hose ends and not just rubber gromets. I also had the hose pop off once after re-routing it. I dont want that to happen again. Anyone have suggestions on valve covers? They dont have to be pretty just functional.

Rob's 73

Just put a breather in there for your track days.

Aardwolf

Is your PCV functioning OK? Mine doesn't have a drop of oil in that. No troubles with the stock covers.

Kubs

Ive tried a breather in the past, but it was at an autocross and it just spilled out on to the header. I put the breather in cause I had one laying around and thought it looked cool.

PCV Valve is brand new and working properly. I never had a problem with street tires but I run A6s and V710s. Apparently my car has smoked in previous events but no one told me until now. I have around 110k miles and I think Im getting some blowby that helps the oil come out.

Since it only happens while accelerating and turning left, moving the gromet hole to the front of the valve cover and putting in a catch can should fix my problems.

Jason

McGyver/Toby would be proud.

Fastguy

I bought a cheap catch can on ebay and run that in line with the PCV and it keeps the oil out of the exhaust.

Kubs

Yeah summit has them for like $27, but what I want to do also is move the vent on the passenger side from the back of the cover to the front. Oil collects in the back so I dont want the vent to be right above it. I also dont want the vents to just push into a grommet, I would rather they screw in. I have seen some people with valve covers that have threaded holes in them but I cant seem to find any on summit without having to drill my heads for perimeter bolt covers.

BrianCunningham

There's been some posts about rigging a catch can.

Oil tends to stack up in the heads, away from the oil pickup, which is obviously bad

Going to a dry sump system.

Kubs

I dont really have the money to fabricate/install a dry sump system. Also I am building the car for NASA TTA class and have to take points for a dry sump. I have a 3 qt. accumulator which will have to do for now.

Aardwolf

When I had the covers off I remember there being baffles. I don't think you'll help anything by different covers with the opening in the front. There's not that much oil there to submerge the baffle.

A catch can on both lines is a good idea. I have one on the PCV side but not on the passenger fresh air side since mine is dry there.

Kubs

There are baffles on the stock covers but for some reason the oil still gets by. I had my covers off to check and the baffles look to be securely in there. I just dont know why it sucks up so much oil.

BrianCunningham

no so much sucks up oil as the g-forces throw it there.

BTW a good running PVC system helps seat the rings.

BrianCunningham

You could try one of these

http://www.eliteengineeringusa.com/Catch_Can.html

SIK02SS

Gatorade bottles are great for any kind of over-flow tank, here's mine in use:

Kubs

What car is that? It doesnt look Corvette..

SIK02SS

nope, vintage formula ford

Slalom4me

The hose from the throttle body to the rear of the p-side valve
cover is a fresh air supply to the crankcase - drawn by manifold
vacuum acting on the hose on the d-side from the PCV valve to
the intake base. Normally, the location of the grommet at the rear
of the p-side valve cover is not an issue because flow is moving
into the v-cover.

My vote is that if oil is present in the p-side hose and TB, then
this is due to blow-by exceeding the vacuum at the PCV,
pressurizing the crankcase and venting backwards out the p-side
inlet hose into the TB. A leak-down test would be one way of
establishing to what extent poor ring sealing is an issue.

If blow-by is the cause, then the ideal solution for the root problem
is to rebuild the bottom end.

In the interim, one inexpensive method of addressing symptoms of
the problem might be to replace the OEM filler cap with an aftermarket
filler cap that has been modified to add an NPT-to-Hose Barb fitting.
A pipe tap can be used to cut threads in the aftermarket filler cap.
The rear grommet opening in the v-cover would no longer be necessary
and could be plugged.
While this arrangement would not provide the benefit of the OEM
separators mounted inside the v-cover under the gromment opening,
it would achieve your goal of relocating the fresh air inlet to the
forward end of the v-cover.

Since there would still be times when blow-by results in crankcase
pressurization and reverse flow out to the TB, it might be worthwhile
to consider adding an external separator/catch can such as the one
from Elite Engineering pictured in BrianCunningham's post. The
Elite is/was available from CF member EG@EnglandGreen.

Other catch cans might not be as effective or attractive, but may
be adequate for the purpose and better suit the budget.

.

mrc24x

Great thinking w/ the Gatorade bottle Kubs. If you are still looking to replace your valve covers......

http://cgi.ebay.com/ebaymotors/Chevy...d=p3911.c0.m14


They clear my Scorpion 1.65 Roller Rockers and they look great for the price. This is the second generation of the fabricated covers. (the first gen didn't use a solid plate on the base and they leaked)


Slalom4me,

I always learn something from your posts. You're a great asset to the forum. Thanks

Kubs

Thanks for the great info guys. It sounds like at 110K miles my issue is blow by. I dont really have the money for a full rebuild. I know its not optimal but do you think just replacing the bearings, rings, and .030 overbore/pistons would be enough? Or do I need to replace the crank and rods as well? I also dont want to have to take points for an engine displacement increase as my ultimate goal is to run TTA in NASA.

Matt -

Those valve covers you listed have no holes. How do you vent your crankcase?

mrc24x

Make your own holes where you want. I used a cone shaped "step" type drill bit to get the size I wanted.