As I was turning the petcock to drain the oil out of my catch can, I came up with this idea: It'd be a whole lot easier if I ran a tube from the bottom of my catch can down to the oil pan -- I wouldn't have to turn that little gizmo anymore.

I'm not really that lazy . . . the bigger benefit in my mind is that it would keep me from accidentally overflowing the catch can if I forget to drain it.

 

Good idea, I don't see why not. Isn't the car setup that way stock? Doesn't the FD drain back into the oil filler neck?

 

Isn't that some pretty nasty stuff in there? I'd rather just drain it.

 

Yea you wouldn't want to put that frothy gunky white crap back into the oil pan as far as I'm concerned.

 

Though slightly different from a piston engines, the rotary "crank case" does see pressure. That's the main reason the catch can works like it does..... I for one would NOT plumb back into the pan (for a few reasons).

-J

 

The more I think about it, the less I like the idea. My blowby wasn't frothy or white -- it was just a little engine oil. But that oil probably has some traces of combustion gasses and carbon in it, so it's probably not the best thing to put back in circulation. I'll just continue to toss it.

 

i would like to hear some reasoning?? curious to know why?

 

There's no bad reason to run it. It will work as long as your catch can is not a "sealed" system. As long as there's a filter element to vent air it it'll work. I've ran it for awhile now. But don't take my word for it... https://www.rx7club.com/3rd-generation-specific-1993-2002-16/oil-catch-can-setup-my-race-car-792344/

 

What I get in my catch can reeks of fuel... I figure that draining it back in would just contribute to greater contamination.

 

just run a dump tube to the street

 

Well fuels going to get into your oil anyway. You need to either get compression check (leakdown if the numbers come back good) or a new tune. The fuel in the oil is related to one of those two. My current map is rich on my car too. I just make sure I do an oil change every 1k. It's not good to have the oil diluted.

 

Draining the catch can back into the pan would be like drinking your own urine!