What are people doing to comply with the requirement to have an oil catch tank on the crankcase breather. My stock L-Jet system returns the blowby back to the inlet and is closed to atmosphere. Should I put a 1-quart catch tank with an inlet, outlet, drain petcock, and no vent to atmosphere in the line that goes back to the inlet? Or should I plug the fitting at the inlet and route the blowby into a vented catch tank? I would like to keep the system closed to atmosphere if possible so as not to have to deal with oil mist making it through a filter on the vent and depositing in the engine compartment and smelling the fumes all the time. With a closed system, it seems that a catch tank should not be required, but I believe it is. All comments/photos appreciated.

Many moons ago I went to SCCA fire school at Road Atlanta before I started racing. I have seen my share of track fires too.

Yes, always use a catch tank on any part of the drive train that emits vapors. If you can rout the vapors into the combustion chambers and out the tail pipe, all the better. Oil vapors also condense out and end up on the track surface. On a cold day you will essentially be crop dusting oil onto the track.

I drove an endurance race last year at Willow Springs. When I was not in the car while others on the team drove, I was safety marshal in the pits. A Datsun 280Z in the race did not have a catch tank on his transaxle. For the first few hours fo the race, when he would come into the pits, his back end would be smoking. His crew told me everything was OK and not to worry. He admitted later that he went through 7 (yes, that is correct - seven) quarts of gear oil during the 6 hour endurance race. When I was out taking my turn to drive, he would pass me and reeked of gear oil. I and the other drivers noticed the track getting slippery as time went on.....When I finished my stint, I asked the marshals to black flag him and bring him in to install a catch tank. They would not do that because he was one of the prettier cars out that day.

Also, how do you make gasoline?...buy distilling heavier grade oil into the volatile vapors that condense out as the different grades of gas.....so what do you think was happening as the 90 weight oil boiled out as vapor from his rear end right next to his white hot tail pipe???? He is lucky he did not catch fire.

So any volatile fumes drifting around your engine bay is likely to ignite and burn your nice car and maybe you.

Thanks Bill. I'm definitely planning on installing a catch tank on the transaxle vent and that should be pretty easy. But I'm still confused about the crankcase breather system, which currently routes crankcase blowby back into the inlet of the engine. Since it doesn't vent to atmosphere, do I still need a separate catch tank for it? If I broke a ring and the crankcase started blowing a lot of exhaust with oil, with the stock system it would not spill onto the ground because the system is closed. It would however cause the engine yo run very poorly and maybe even kill it. I guess it could possibly pressure up to the system to the point where it would split a hose and dump everything onto the ground, but that seems unlikely. Anyone out there putting a catch tank on their stock closed crankcase breather system?

Mike

A stock 1.8?
It vents to the intake... from the factory...doesn't it?

Crank case blow by gets routed into the intake and into the combustion chambers to be burned with the gas. IT all then goes out the tailpipe as burn stuff. You should not need a catch tank.

The box on top of the engine that the vent comes out of is a built in air/oil separator so should count as a catch tank but it doesn't count. I routed that vent to a ct on the firewall just to be compliant. It vents through a tiny air filter element.