recommendations for race motor overflow

[Jeff Burger]

I need to set up an oil overflow tank for my race car motor . It seems pretty straight forward however any recommendations or useful information appreciated. pictures of your set up maybe?

[sjf911]

I assume you mean a catch can for your oil tank vent. I use a Canton series 24 oz that has a petcock to drain it periodically. It has a small filter on top to vent to atmosphere. This is probably a good setup for a race motor but the fumes vented into the engine compartment get picked up and pulled into the heater. I am going to have to figure out a way to vent it outside of the engine compartment.

[CBRacerX]

Speaking from experience, you want to use a location that does not produce a vacuum at speed, to avoid drawing oil into the vent can. Wheel wells and other exposed locations are not good.

[Walt Fricke]

Jeff

I do all my venting up front from the front mounted oil tank - vent line from engine goes to it, separate line to catch tank. I used to run the line from the tank vent more or less directly down to my catch tank, which was sort of at floor level where I now run brake cooling ducting. I'd have to empty the tank from time to time, and the surrounding area was always a bit oily.

Running the line as seen in the pictures up before it turns down seems to have resolved that. Looks like the oil mist doesn't get over the hump, and drains back. Putting the catch bottle in a handier place was intended to make it easier to service, but so far I haven't had to.



Note the low buck tank and fittings. The filter is a piece of scrap foam. These have worked fine for about 15 years. I don't recall if you have a front oil tank or not. I've often wondered if I should not just have two catch tanks/filters, one for the front tank, and one just for the motor. Simplify the plumbing a little. Car came in this configuration, though, so I just kept it.

At least you have a lot more room in the engine bay than the turbo.

Walt

[Walt Fricke]

Another view:

[Jeff Burger]

thanks guys great input - keep it coming.

[CBRacerX]

What Walt said - I had the same config after trying a few other 'low line' solutions and they came up short.

[Mahler9th]

Not sure what car? '87 with a 3.8? What may make most sense depends on what you have.

My race car is a '75 911 with a 3.8 liter engine. It has a mid '70's era oil tank. My breather lines comes from the top of the engine to the normal position on the tank. Then, instead of the normal tank vent line path, my tank vent line goes from the tank through the rear firewall, to the bottom of a ~1 quart cylindrical container mounted on the cage high up near the passenger b pillar. There is another hose at the top of this reservoir that comes back through the fire wall and back toward the tank, exiting the chassis through a small hole next to the tank and attached to another ~1 quart cylindrical container that is mounted behind the rear wheel. That final container has a petcock. Several of the race cars built by the same person in our area have the breather/overflow set up this way. He is an expert. In most cases, he just has that final hose pointed down at the ground behind the rear wheel. I decided to add the second container because I had one laying around and it weighs nothing. Not much oil gets in it.

This is an old school 911 approach.

[Jeff Burger]

car is a track car only - 90 C2 with a 3.6 Racetek ITB motec motor. oil tank is the stock unit.

[Mr9146]

Go factory ... 356 washer bottle.

[9elf]

Best access I could find for a CIS engine bay. Easy to drain if needed. Hose is not hooked up in this pic.

[CBRacerX]

Originally Posted by Jeff Burger

car is a track car only - 90 C2 with a 3.6 Racetek ITB motec motor. oil tank is the stock unit.

Jeff - if you are keeping the 1990 stock tank then it should be easy, just fit a typical small AL tank in the engine compartment attached to the stock tank breather return (the one that was going to the C2 airbox). No need for an elaborate solution as the stock tank does a good job of removing oil mist from the breather. The post from sjf911 has this.