[92GTA]

I have a 461 that I'm going to be going road racing with. It's the engine that came with the car so I need to work with it until I can do my own engine in a couple of years. Figured why not wear this one out first right First, I don't have baffled (drippers ) valve covers and that's been causing me to mist out of my driver side breather. I've been told to replace those so I'll have to run the 3/4" spacers too to clear my Comp rockers. Should help with less catch can oil at least.

I'd like to totally re-do my breather set up to something more appropriate for the rigours of road racing, amateur open track day stuff mind you. I'm almost done with my T56 Magnum swap so that's going to be keeping my RPMs up there on the track. By the time I hit the track, I'll also have my new E-heads and cam which I'm hoping will be pushing me to nearly 650 at the motor. I don't wish to do a vacuum pump on this engine. On my future engine in a couple of years I will probably go dry sump which will give me some good vacuum action, but none of that on this engine. Just the baffled Canton road race pan on this engine.

What would be an optimal setup for trapping any oil mist in a catch can and not running that hose from the PCV in the valley cover into the intake? Do I just run the valley PCV and the 2 valve cover breathers all into a vented catch can?

Thanks!

[Skip Fix]

Also check on putting a vent/catch can for the tranny. I know the Late Model asphalt cars all require them. My 78 TA tossed auto trans out the vent tube in hard turns with road race slicks so had to make a longer vent tube for it.

[92GTA]

The breather tube on the Magnum is nearly 3ft and has a nice little breather cap. I'll for sure be keeping an eye on it. I've installed a temp gauge in the trans because I suspect after just a few laps that it will get upwards of 250-300f so I may need to add a trans cooler with a pump. We'll see. I need to wrap my exhaust first as that will help with trans temp a ton. I'll be keeping an eye on my rear diff temp as well, I have a coiled 3ft hose with a little K&N breather on the end for it.

[Sirrotica]

Extending the breather caps with a short stick of exhaust pipe with push on breathers, (6-8 inches) is how many circle track racers keep the suspended oil from exiting the breather tubes. Another circle track remedy is to use old socks to cover the breathers to keep oil in and dirt out. Just wash the socks, or replace with new socks every once in awhile.

Currently there are cotton mesh filters breather caps to keep the oil in and the dirt out, but before they were available we made our own with what we had to work with (old school)……………

These are chevy valve covers, but you get the idea from these images:



Of course no one makes premade valve covers for a Pontiac, requiring you to make your own. I made my own for my cars back in the 70s. On a car that only makes left turns the cover with the 2 stacks goes on the left head, centrifugal force helps the oil drain back to the engine. ...

[92GTA]

Thanks for the tip. It crossed my mind to do that but I'm wanting to do something a little more sustainable. I'm not to keen on swapping out a wrap around a breather in between sessions and I think a catch can is better in the long run.

So, if the above covers the breathers, what do I do with the PCV in the lifter valley? Do I remove the valve and run that straight to a catch can as well?

[Sirrotica]

I never ran any PCV system, just plugged it off and used the 2 breathers. If you look at any 50s car they just ran a tube down below the engine (called a road draft tube) and vented the gases to the atmosphere below the floorboards.

If you wanted to continue to use the PCV system you'd want the socks over the breathers, or the cotton mesh style breathe caps that they now make. That way you have clean air coming into the breathers, same as GM used the oval shaped breather element connected to the right valve cover by a tube with the breather element on the end of it.

Drawback to using any open breather system is when the rings get worn the smell of blowby is present in the cockpit. If the rings are up to snuff you won't get the smell in the car.

[92GTA]

Yeah my 56 Corvette has that road tube.

Ok, I didn't know if I should just block off that PCV port or route it with the breathers. Sounds like I'll just block it.

Thanks!

[Sirrotica]

Looking around the net I found a good article on breather systems without vacuum pump assist, such as dry sumps:

https://www.enginelabs.com/tech-stor...d-air-control/

[92GTA]

Originally Posted by Sirrotica

Looking around the net I found a good article on breather systems without vacuum pump assist, such as dry sumps:

https://www.enginelabs.com/tech-stor...d-air-control/

So my take away from that is I should run a catch can on my PCV (and I guess leave the valve in place, they don't talk about the PCV valve as such in the article) between the valley and the back of the carb, and run my breathers on another.

[rod cole]

Personally I would plug the pcv valve.
In road racing there will be many high vac times that will most likely result in lots of smoke exiting the corners. Speedway has many ways to vent a engine the best looking one is a crossover system between both covers with breathers mounted in the crossover system. The stands you weld in the covers have baffles in the bottom then 6 inches of rise to allow drain back. You could add coarse media <steel wool or other > in that six inches to improve separation. Also the edelbrock heads will need the drains massaged there are threads here discussing this. Also there is a guy on here who races a pontiac I believe is named HO428 who would be a wealth of knowledge he has been there and done that. Rod Cole

[92GTA]

Thanks a lot for the great info and suggestions. Very good info to know about the e-heads.

[TCSGTO]

I used one of these in a stock valve cover to cure an oil consumption problem with a MR-1 block that was sucking excessive amounts of oil out of the valley pan PCV location. On top of the tube is a baffled grommet with the PCV in it running to a catch can. I also put a stainless steel scrub pad wrapped in stainless screen in the tube for insurance.

This has stopped any oil from reaching the intake. The catch can is really not needed since it has just a slight layer of oil at the bottom of the can after many miles of driving. Without the tube and running the pcv in the stock location the can would have a noticeable amount of oil in it after just a moderate drive and the tailpipes had oil residue in them. My valve covers are not baffled. I think the solid lifter valley of the MR-1 pools alot of oil right under the valley pan that gets drawn thru the pcv system. On a stock block with the open valley the oil drains straight to the pan but with a long stroke at higher rpms oil consumption can still be a problem.

The tube is cheap and you can experiment with it and see if it helps before trying another solution.

https://www.speedwaymotors.com/Twist...ubes,7772.html