1st gen rx7 oil catch can

[sevenracer]

Hey,

Looking for some help with a problem that showed up in my first race weekend this year.

For a catch can, I have some heater hose running from the vent on the oil filler neck to a plastic oil bottle with vent holes in the top.


After a track session, I have almost half a quart of oil in the bottle, and some on the frame around the bottle.

Any idea why so much oil would be coming out of the engine? I did not have this problem last year. The hose is pretty much at the high point when it attaches to the oil filler neck. Should I route the hose up from there before going down to the catch can?

I run the car just a little over the full mark on the dipstick. I have a 90psi oil reg, and an oil baffle plate.

Thanks,
Neil

[ddewhurst]

Neil, I'll stick my neck out where it's never been before & presuming you have done nothing to the motor. Firts start a session with the oil at a known level in the motor & an empty over flow container & measure the depth of the oil in the container after the first session. Do not add oil, after measurement of oil from first session empty the over flow container. Do a second session of the same number of laps & measure the oil in the over flow container. Compare amounts of oil from the first & second sessions. If there is less over flow oil after the second session maybe your filling with to much oil. I have had the level slightly above full & have never had an over flow issue. Being that you didn't have this issue last year might the seals need a little ATF time to free them & the springs up ? Pressure is comming from some place to blow the oil out.

[Speed Raycer]

^^^That was going to be my response... blow-by.... but I couldn't dust the cobwebs off in my mind to even remember if blow by was possible in a rotary :D

[ishod]

FWIW I've purchased two race motors and each one had the vent pipe sealed with a rubber cap. Same builder so maybe this is just his thing but he knows 12A race motors and I assume he knows what he's doing. I've never had a problem with oil. I would suggest not overfilling the oil level.

Peace

[sevenracer]

I'll have to measure the amount of oil each session a little more closely next time I run, but I'm pretty sure I ran at least one session below the full mark - and still had oil in the catch can after. So maybe blow-by is the problem.

A followup question - Who's running a catch can on their 12A and where's it connected?

Thanks,
Neil

[ddewhurst]

The windshield washer bottle. Never oil in it. This should strat a legal/illegal discussion. :018:

[lateapex911]

.

A followup question - Who's running a catch can on their 12A and where's it connected?

Thanks,
Neil
[/b]

My knowledge of the internals of the rotary isn't great enough for me to render a qualified opinion, but blowby (oil seals) was my first thought.

I too use the windsheild washer fluid bottle for my overflow. I think it's pretty dry. (And the connector going to the motor is loose, just in case)

[kbailey]

I have the catch can connected with 1/4" or so hose to a washer bottle on the shock tower above the header (I hope I never spray oil out of the top....). Anyway I never have oil in the can. I am connected to the hose barb on the fill tube also.

I did read a posting last year about someone that had an oil pan baffle that was interfering with the dipstick position causing a serious overfill. Longshot, but worth a peek. Is the dipstick seating? FWIW I try to run about the middle of the level marks but I have run at the very top without trouble.

Good Luck!