Throwing oil out of valve covers

[Clois Harlan]

I gave the ole FE Cobra a good thrashing this weekend in Omaha's (Council Bluffs, Iowa) Mid-America race track. Nothing broke and I couldn't be happier with my set up BUT...

I am throwing oil out of my right side valve cover breather cap. Makes a real mess under my hood but other than the mess there doesn't seem to be any other problems.

I am running K&N valve cover filters and at the rear of my manifold I am running another stack type breather I bought from Finish Line. I am not running a PCV and don't want to either. Question is: Are there any of you FE RACERS that have a particular PUKE TANK set up that you found to work well.

The only time I have this problem IS ON THE RACE TRACK. Hard braking from 130 mph straight aways and taking slow corners at 60 mph and faster corners at 90+ mph

Any ideas??


Clois

[Bruce Edwards]

Clois,

First question would be why do you not want to run a PCV valve? Second question would be does the valve cover set have the steel baffles in them? If the baffles are not installed the oil will splash out of the vent/ breather.

[Coloradocobra]

What size oil restrictors are you running? Could be that you could go to a slightly smaller size and get less buildup in the valve cover. Also, are your drains clear? Make sure your rocker shafts (depending on the make) are installed "right side up" as this can also lead to excess oil in the valve covers.

What breathers are you running for the crankcase? You need to minimize crankcase pressure to allow the oil to drain back down. A breather at the filler tube in front as well as a rear breather may help.

You might try a cut up old valve cover to run the motor and see how much oil you are getting in the cover area. This could help you decide that a smaller restrictor will still provide adequate lubrication.

Just some thoughts,

Gary

[Cracker]

Clois,

I'm going to jump in here with a question on the same topic.
Unlike you I am running a PCV valve off the rear of the intake and breathers on each valve cover. When pushed hard I've noticed the same problem as you and yes I do have the aluminum splash guards in the covers. Other than a little mess it doesn't seem to be a big problem. It is an FE as well by the way. Anyone with an answer to Clois question is of interest here as well!

[bmcmillan]

This could be good news and bad news. I have never been on that race track. If it has some long, fast left handers and you are losing oil out the right side, it means that you have one of the rare cobras capable of more than 1 G lateral force!

All 90-degee v-type engines will have the oil flowbackwards up the drain holes to the valve cover of the outside side at 1 G (think about it for a while - it will make sense). This is caused by centrifugal force.

Three solutions:
1) If you really like tracks with long, fast turns, you need to install an oil pan designed for this purpose. It has trap doors to keep oil in the pan - not running backwards up the drain holes.
2) An easier solution is a crossover tube between the valve covers. The breather needs to be on the crossover and the crossover needs to be the only opening in the valve covers.
3) This is the least acceptable - drive on tracks where the corners are not as long so the oil cannot run up to the valve covers.

I learned this lesson after multiple blown engines at Willow Springs in So. Cal. You are in turn two for what seems like five minutes and puckered up in turns eight and nine longer.

Sounds like you have your car working well and you know where the throttle is and what to do with it.

[Clois Harlan]

I just got off the phone with my engine builder. (I use this form to help me offer up intelligent questions to him so he can better diagnoise my problem).

First of all there are several very fast long turns both left and right hander as well as for straight aways with the longest being over a quarter mile with the other straights an 1/8th mile or less. Mixed into all this are a couple decreasing radius turns. I am running a Canton baffled oil pan and my oil pressure in the most severe turns does not drop below 40 psi.

Anyway after speeking to my machinist he suggested using a quart puke tank from Milodan with a breather filter mounted on top with a 3/8" hose from my right side valve cover breather to the tank and then another 3/8" hose over to my left side valve cover breather. He tells me this is fairly common with high hp engines that run oval tracks and road courses. I am going to go look at some puke tanks over lunch today.

As far as pulling 1G I can't answer that but my left should is sore today even though I am now running Ultra Shield road racing seats.

I will post to this thread later.

Clois

[MidOHasp]

PS... bmcmillan...

In your example, the oil would be coming out due to centripetal force. If the valve covers were holding the oil in, they would be doing so with equal but opposite direction centrifugal forcce.


Sorry, my high school physics teacher engrained the difference in my head, never to be forgiven again. Yes, I remember high school physics. Better than I remember college history!!!

[PatBuckley]

And all these years I thought that centrifugal force was what caused things to want to go in a straight line and centripetal force was it's opposing force.....

[MidOHasp]

No Pat, you're thinking of gravity...which is actually named after Newton Gravity and explains why the shortest distance between two points is a circular triangle.

JP

[SFfiredog]

Hello boys,

May the Force be with you.

I think the issue isn't so much oil climbing up out of the pan as the oil that is being pumped up to the rockers is being held there by lateral forces. Enough oil is suspended in the valve cover to eventually climb out the breather.

I would run a minimum of a 5/8" hose, preferably 3/4", from each valve cover to a large remote breather (puke tank)
Mount the tank and lines high enough to allow the excess collected oil to drain back from the tank into the valve covers.

Or do like Pat and go to a dry-sump

--Mike

[RICK LAKE]

Clois Harlin Clois you are having alot of problems with that car. I run a PCV valve in my R/S side valve cover, and a filter on the L/S. Your problem may be too much pressure in the crankcase and block. At high rpm and g turns the oil will stay and not drain down. Have you but a vacuum gauge on the engine, not the intake and road tested it?? You may have built up too much pressure in the block could also cause the problem. With the amount of hard racing you are doing, You should go to a dry sump system. You might want to look at a vacuum pump for the motor also to help the rings seal better and help control the oil in the block. How's Lew? Hope to see you at R&G in sept. Rick Lake

[Clois Harlan]

First off the engines performs beautifully. Except for a little blow by at the right side valve cover filter.

I just came from my engine builders and he tells me he installed .090 restrictors in my heads and thinks that I may want to go down to .070 restrictors. He is making me another set to pickup tonight but did suggest a puke tank with AN 10 lines similar to what Mike had suggested. He did mention a dry sump system too.

Clois

[bmcmillan]

Clois,

A baffled oil pan won't do it; it needs to have trap doors in it.

Also, if you see the oil pressure drop, its too late. The pump has sucked air and if the engine doesn't blow up, there still will be permanent damage.

Last thing - if you are watching the oil pressure guage, you can't be going fast enough. You can be honest with me, I'm not your engine builder.

Bmcmillan

P.S. The high school physics guys are absolutely correct - the oil feels the centripetal force, the valve covers feel the cetrifugal force. In fact I think everybody is correct.

[ERA Chas]

Clois,
I've had your problem too. I have a rear breather, a front oil fill breather and two valve cover breathers. Solved the problem with no detrement by placing some "Scrubbie" stainless element in the oil fill breather tube. Ask you Missus to find you some at the supermart. It's sorta like Brillo, only stainless threads. Cut off about two inches worth and gently pull apart, then insert into fill tube. Traps flying oil but lets out crankcase pressure. No Splatter. Remove to add oil then re-install.
Hope this helps. It works well for me. And I have .090" restrictors.
Good luck,

[Clois Harlan]

BM....

The Canton oil pan I have is a road racing pan and incorporates all the requirements associated with road racing. I only check my gauges after I have a 15 or 20 car lead on the field and can glance over at them. In all seriousness after 30 or 40 laps instinct takes over to some extent and I can take a look at the oil press and temp gauges but you are probably right I could be going faster. Stones aren't nearly as big as they were when I was 21.

I refer to those insane times as my learning curve. Now I have learned that some things that you fall off of you can't get back on and everything is not just like riding a bicycle. But I sure appreciate the ones that are.

Thanks for everyones input (some really good ideas...that will probably work for me too).


Clois

[bmcmillan]

clois,

Don't get too depressed. Most Cobra reps are evil handling - especially the ones with 600lb. motors in front like yours. It is not uncommon to be blown off by a 240Z or a 320i or even an almost-stock Camaro or two. They don't need to lift in the corners.

Dirty side down. Out.

[ERA Chas]

bmc,
Don't equate your experience with your Hybrid's inadequacies to the rest of the well-driven, properly set-up Cobra community. Camaro's , Z's and 320's reside in other time zones.

[Clois Harlan]

Just for the record.

My times were better than the only Z06 at the track last weekend as well as one of the BMW M3, 1999 Z28 Camero, couple of the Cobra R's (definitly a driver issue) and most of the cars in all the other classes.

Clois

[bmcmillan]

Didn't mean to offend anyone - that's why I said most. Sounds like you guys have yours working well... and know how to drive them.

All the kits I drove before building my own from scratch were oversprung, overcammed, low-tech, but beautiful cars. But that was 15 years ago. I know a lot has changed in the last few years in the chassis department, but I don't drive anybody else's cars these days. I only go by what the owners tell me at the shows and at the race track.

I think there are going to be some fast cars at Willow Springs this weekend. Time trials.

[Excaliber]

My oil pressure drops to about 40 in the corners or under hard breaking.

Clois, that is just about the same time those dual quads flood the motor. All though improved, I can see the hand writing on the wall, single carb is the ultimate solution.

I recently hooked up the PCV valve with a tee to BOTH carbs for equalization purposes. Personally, I like a PCV.