Still blowing oil

[Fantm 34]

Hey guys so as the headline states im still blowing oil out my catch can. So ive done plenty of reading on the oil control page and thought i had most of them covered. Ive got a massive catch can baffled and vented to atmosphere, head drain/breather, can returned to sump and another vent from catch can to top of sump. Thought i had a 1mm restrictor but just puilled the head off to find it was 1.25. So ive tapped a 1mm on top. Just wondering if this will be enough or will the problem re occur. Its a track drift car running on e85, so havent had a chance to run it yet. Just fingers crossed the 1mm will fix it. Also running a aviad external pump setup. Has anyone had experience with these just purely pushing too much oil volume? will no in a couple week but just gettin peoples thoughts. Cheers

[KiwiRS4T]

Do a compression test - maybe you have massive blowby.

[Fantm 34]

Nope, did the compression test before pulling head off. 160 or close enough to all cylinders. not blowing constantly but on a few of the big longer corners.

[Dobz]

Rb25neo I'm assuming? I'm not too familiar with the restrictor setup on them but my rb26 is happy with a single 1.3mm restrictor. Is it actually pushing a volume of oil out of the vent or is it just getting wetness from condensation/oil mist?

[KiwiRS4T]

1. What do you call a massive catch can? Is it 2 litres or more?

2. Is it baffled so the flow goes past or across all the baffles before exiting the catch can?

3. The lines going to the sump are they half inch and do both go well above the full level of the sump?

4. Restrictors - not sure what engine you got ...have you blocked off the front feed and put the 1.0mm in the rear feed?

5. Is your oil pump adjustable from the outside? If so what pressure are you getting and can you try turning it down? When you say you get oil blowing out on the long corners what happens to the oil pressure - are you emptying the sump?

New smaller restrictor may fix it.

[Fantm 34]

Hey mate yes is bigger than 2l, it has 2 pipes from top of catch can to the bottom with 2 baffles with only a small gar on the edges of the can so air can pass to the breathers at the top of the can. att hose are -10 braid and go to almost top of the sump. Was maybe exaggerating withthe massive. but after a few corners was enough oil spraying out to coat the intake side with oil. Restricted the front to 1mm and rear is blocked. but it was a 1.25,, so hoping this may make a little difference. find out this weekend when i hit the track. Nah id doesnt empty it, was more of a light mist coming out. just looked bad as everything was soaked in oil. oil levels didnt drop too much tho. Running the aviad external pump. Watched it today on the dyno and at full noise was sitting at 800 kpa, so bout 120 psi. which we thnk is too much. Gunna try wind it down tomorrow morning. Just gunna ring the up and see what ive gotta do. See how we go..

[KiwiRS4T]

Less pressure and smaller restrictor may do it. If not instead of venting to atmosphere put another catch can from the vent rather than pull the engine apart again!

[Fantm 34]

Yea i agree,, that did suck! with the 1mm restrictor what do u reckon would be safe oil pressure at full noise?

[KiwiRS4T]

I reckon 1 bar per 1000 revs would be more than enough so about 100psi (but always use fully synthetic oil as a precaution). Also run one breather to the bottom of the catch can so oil can run back off boost.

[Fantm 34]

yea im running brad pen, some decent oil. Is that another line? if theres a breather at the bottom of the catch can wouldnt that just force oil out as it being blown down by the tappet cover?

[KiwiRS4T]

Should  be stuff all coming out the tappet cover and anyway you have it vented to atmosphere...

[Fantm 34]

Yea its vented to atmosphere,, but before i made the bigger baffled can, it filled the can in 1 lap down the drag strip. a few more laps on the drift track. Its still got 25 covers so if this doesnt work will have to get a set of 26 covers.

[KiwiRS4T]

2 hours ago, Fantm 34 said:

Yea its vented to atmosphere,, but before i made the bigger baffled can, it filled the can in 1 lap down the drag strip. a few more laps on the drift track. Its still got 25 covers so if this doesnt work will have to get a set of 26 covers.

?

[Fantm 34]

26 covers?

[No Crust Racing]

Wow, all that work and still blowing oil out. 

Are you massively overfilling the sump or something? 

My view has always been pressure in the sump stops the oil returning from the head, those oil drains are just pressure balance tubes effectively. So you want to get the pressure out of the sump. 

All I did on my GT-R when I wanted to track it was added an additional catch can to the system to allow the sump to vent as well and I had no issues with oil in the can(s). 

My setup is simply a single catch can, properly baffled, feed from both rockers and properly plumbed back into the rear turbo. 

All I did was added a second catch can with a sump drain, that effectively became a vent, and plumbed that inline with the hoses going into the other catch can. No issues for me with a slightly overfilled sump (RB26)

On my track car, CA18, I have 2 separate breather systems, one for the top and one for the bottom of the engine, both baffled cans and vented atmo. I tried a million things until this setup and now there's no oil in either can as all the pressure can escape the motor. 

If you can, give the sump it's own breathing system to atmo and see what it does. 

 

[Fantm 34]

It’s only sightly overfilled when engine stopped so when running should roughly be sitting on the full mark. Will prob try the second catch cam idea next if the restrictor doesn’t work. Cheers for the input fellas