gents, on sunday i went on a trackday in the 2.35 subaru. everything went well until i hit fuel cut coming out of hairpin (syvecs done its job) engine cut and i coasted down the straight and into pit. i opened bonnet straight away to find my catch can full (1ltr) after 2 laps and oil puked everywhere were its had pressure build up and its thrown it out breather on top of catch can.

My catch can setup is not a sump return yet but i have been advised i need this. the current setup is both heads running to can inlet, the drivers side head is t-piece with the crank breather to 1 port on can and the passanger side rocker is into the other.

what could cause this massive oil fill in such a short period of time?
could coasting to a stop with no ignition on and clutch not pressed down cause this?
can oil run from rockers up the lines into the tank through cornering if lines are big and not restricted?

the way it has thrown the oil out the top breather makes me think there was alot of pressure to cause this.

Will an RCM time attack attached my my RCM baffled sump other port fix this or have i another issue at play here?

The fuel cut issue i can sort easy enough.

ty

gareth

 

Are you running avc's heads with the single breather outlet, & the other bigger balance pipe outlet ?

 

sorry yes avcs heads and single outlet were other is bunged i believe

 

 

also RCM 11mm Modified Oil Pump

 

Is it the larger 16mm that is bunged in the cam cover ?, where does your main crankcase breather vent to ? have you still got the pcv valve fitted ?

 

yea so drivers side head is tpiece to crank and on to catch can it also runs to pcv here also. Passenger rocker straight to can. Unsure what one is bunged it’s the rear one. Never had a problem on the road flat out or rollers

 

https://rogerclarkmotorsport.co.uk/s...-kit-2001-2007

 

Any thoughts @MOTORS S GT

 

I don’t know what is causing your issue but I’ve been running an rcm track attack catch can and a group n baffled sump for a number of years and it works very well, if you are doing regular track use then it would be worth looking into

 

Cannot see with the info given, its a problem with the breather setup, apart from getting the pcv out of the system, its a lot of oil to lose for a couple of laps, if the engine is healthy, the back to sump system will handle the situation, but won't stop the oil actually getting into the breather system.
What track did this show the issue ?

 

Thank you. It’s all track use so I’ll order this up abs return to the spare port on the RCM baffled sump. It will need to return at a great rate

 

it’s one in Northern Ireland Kirkistown. All right hand corners so bad for Subaru fuel tanks

braking hard twice from 130 to a right handed one of a very fast hairpin. I know it’s a hell of a lot of oil for a few laps