Another Oil Control Question.. Sorry

[KiwiRS4T]

You said early on that you had a sump breather running to the cam covers!!?

I have no head drain and two 1.0mm restrictors. I have drilled and tapped two holes as high as possible in the sump forward of the dip stick and run one hose to the top of the catch can and one to the bottom for a drain (might stick a one way valve in it as some have suggested). I now get no oil coming out of the cam cover vents. The oil which was being pushed out at extended WOT (this is on an RB30/25) was going nicely back down the drain. On my last outing I got some oil coming out of the catch can breather after a few laps probably because I have overdone the overfilling trick (poss 7L or even more) so I will reduce it to 6L and I expect it will be fine.

[abr33]

You said early on that you had a sump breather running to the cam covers!!?

I have no head drain and two 1.0mm restrictors. I have drilled and tapped two holes as high as possible in the sump forward of the dip stick and run one hose to the top of the catch can and one to the bottom for a drain (might stick a one way valve in it as some have suggested). I now get no oil coming out of the cam cover vents. The oil which was being pushed out at extended WOT (this is on an RB30/25) was going nicely back down the drain. On my last outing I got some oil coming out of the catch can breather after a few laps probably because I have overdone the overfilling trick (poss 7L or even more) so I will reduce it to 6L and I expect it will be fine.

Yeah the sump to cam cover vent was intended to reduce the work for oil drains.. I will probably now feed it to catch can

[sriver killer]

Yeah the sump to cam cover vent was intended to reduce the work for oil drains.. I will probably now feed it to catch can

Any news on this? Ive currently got a T piece in drivers side rocker cover that links sump----->rocker cover-----> catch can. Require a check valve?

[KiwiRS4T]

I have solved my spewing out oil problems as above.

I have not relieved/drilled out the oil returns because I don't want to pull the engine out and strip down the motor to clean the block afterwards but it seems a good move if you are at the building stage.

What I have (RB30/25 with VCT and an N1 pump):

2x1.0mm restrictors

2 x 1/2in holes drilled and tapped as high as possible driver's side of sump - one hose leads to the top of a catch can the other to the bottom for a return (don't have a non-return valve in it but that seems a good idea and I may do that) . There is pretty much nothing coming out of my cam cover breathers now and I have them T'eed and going in to the catch can.

This has enabled me to do two full track days without covering my engine in oil and exiting in a cloud of smoke. There is some oily mist coming from the breather on the catch can but I have a plan to deal with that.

I have another catch can and will run the breather from the first into it as well as the cam cover breathers, and baffle it to try to seperate out the small amount of oil that comes through. I will vent this second can to the turbo intake.

Breathers from the sump to the cam covers are not a good idea and the "head drain" at the back of the head is not really usefull for anything.

[r33_racer]

And once more for good measure

[abr33]

Any news on this? Ive currently got a T piece in drivers side rocker cover that links sump----->rocker cover-----> catch can. Require a check valve?

I got a one way valve, havent sorted this yet, in that iv done nothing about it having been street driving only and no track work for a while. I plan to get it happening asap