Oil Control In Rb's For Circuit Drag Or Drift

[t_revz]

Currently ive got a 25/30 that enjoys running with plenty of oil in the head and not enough in the sump causing surge issues under heavy braking when doing dragging and track.

currently running stock pump and 1.5mm restrictors.with no oil drain from catch can to STOCK sump

Moving to n1 pump, 1.5mm restrictors and oil drain from catch can to ASR sump

Ive attached a diagram of my catch can setup. That is exactly how it is except I do not have a drain back to sump currently.

I am going to ventilate the sump better by running a 17mm id hose from catch can to sump for oil return.

Ive had a good read through this thread, and wonder if an additional oil drain from cylinder head is required, Or just ventilate the sump a bit better will do the trick.

Ive attached a pic from a bung in the cylinder head that seems to be at the bottom of the cylinder head,passenger side, where oil sits. Potential oil drain? or not required.

Going off the chart at the start shouldn't you only have the rear feed 1.5 or smaller and other 2 in the block blocked? Maybe just a blank in the middle feed will stop some of the issue

[sriver killer]

Going off the chart at the start shouldn't you only have the rear feed 1.5 or smaller and other 2 in the block blocked? Maybe just a blank in the middle feed will stop some of the issue

a better option? that will definitely help with keeping the oil in the sump.

[The Bogan]

If its got VCT it needs one for that, but for the two in the block block the center one and try a 1.5mm at the rear.

[sriver killer]

If its got VCT it needs one for that, but for the two in the block block the center one and try a 1.5mm at the rear.

vct feed via tap and drill on the side of the rb25 head.

plenty of other cars working with only 1 1.5mm head feed from rear?

[KiwiRS4T]

I have 2 x 1mm restrictors and two 1/2 in breathers from sump to catch can (one acts as a return) no "drain" from head. Completed a full track day for the first time with this set up and pretty much nothing coming out of the cam cover breathers now!

[r33_racer]

So you have one breather from the inlet side of the sump and one from the exhaust?

[KiwiRS4T]

So you have one breather from the inlet side of the sump and one from the exhaust?

No - I just have two side by side on the inlet side - one goes to the top of the catch can one to the bottom - I suppose if you had the catch can somewhere in the middle you could run the drain to the exhaust side.

[r33_racer]

So they would both be working as vents then. I have a similiar setup on my car. I have two dash 10 vents off the inlet side of the sump.

[TiTAN]

Ive attached a pic from a bung in the cylinder head that seems to be at the bottom of the cylinder head,passenger side, where oil sits. Potential oil drain? or not required.

r33 racer has previously posted the thread and fitting required to put a line/hose from there.

i have one fitted to my engine, due to its location you may need to grind the manifold plate for clearance and i would suggest running a solid metal tube for reliability

[kitto]

r33 racer has previously posted the thread and fitting required to put a line/hose from there.

i have one fitted to my engine, due to its location you may need to grind the manifold plate for clearance and i would suggest running a solid metal tube for reliability

I'm doing this exactly. Finding an off the shelf metal AN pipe is the hard part though.

I'm also running a drain (vent) from the rear of the head to the driver side of the sump, i've drilled out all the drains in the head and block to 9.5mm, die ground out the rear block and head drains. I'm also venting the driver side of the sump to the top of the catch can with a -12 fitting. I dont plan on draining the catch can back into the sump.

Is anyone able to tell me exactly how using two separate catch cans in series works and its advantage.

Cheers.

[sriver killer]

I'm doing this exactly. Finding an off the shelf metal AN pipe is the hard part though.

I'm also running a drain (vent) from the rear of the head to the driver side of the sump, i've drilled out all the drains in the head and block to 9.5mm, die ground out the rear block and head drains. I'm also venting the driver side of the sump to the top of the catch can with a -12 fitting. I dont plan on draining the catch can back into the sump.

Is anyone able to tell me exactly how using two separate catch cans in series works and its advantage.

Cheers.

i didnt notice that post until I had a look back a couple of pages.

I am about to invest in an asr sump so I might be able to get a couple of bungs welded to the side for oil drains from catch can + cylinder head,

[kitto]

i didnt notice that post until I had a look back a couple of pages.

I am about to invest in an asr sump so I might be able to get a couple of bungs welded to the side for oil drains from catch can + cylinder head,

I bought a custom ASR sump. The top of the range one, heaps of bungs on it. Built to my specs. $1200 or so later :S

[sriver killer]

I bought a custom ASR sump. The top of the range one, heaps of bungs on it. Built to my specs. $1200 or so later :S

no good?

[kitto]

no good?

No its good, they are good. The sump unfortunately didn't fit when i received it. It ended up being they didn't follow my specs to the dot and the sump ended up fouling.. However i explained the issue and John happily said send them back with the issue marked on the pan and we'll fix it. He even paid for the postage from me to them. Which i was impressed with.

I was quite happy with the service. Definitely a work of art thats for sure! They are flat out and John takes a little bit of time to respond to emails.

I got the club circuit pan built to my specs to fit into an R31 engine bay with about 6 fittings on it.

[tiels32]

Try Lewis Engines for an extended, winged, baffled sump. And he'll weld however many more fittings you want onto the sump. Only cost $420 plus extra for each fitting you got welded to the sump.

Edited May 17, 2012 by tiels32

[KiwiRS4T]

I am coming to the conclusion that the "drain" from the back of the cylinder head is not just unnecessary but actually undesirable. It is doubtful that it drains any oil back to the sump and so some people think it acts as a breather for the sump. Judging by the airflow that comes out of my breathers (and I have had a leak down test which discloses no excessive blow by)I would say that it probably has the effect of blowing oil in the cam covers out through the cam cover breathers and it is better for the sump breathers to go into a catch can.

[KiwiRS4T]

Is anyone able to tell me exactly how using two separate catch cans in series works and its advantage.

Cheers.

I am currently using two completetly separate catch cans but plan to use two in series.

Right now I have one 2L catch can with two 1/2in breathers coming from the sump - one to the top and one to the bottom of the catch can. At extended periods of WOT some oil gets pushed up these breathers and I suspect, but don't know for sure, that it will be worse when powering through a left hand corner. I have a Tomei sump baffle kit but not an extended sump (which is a very desirable feature in a track car) so I don't want to lose too much oil ...and so I let it run back via the lower breather when the pressure is off.

I have another catch can which takes the two hoses from the cam cover breathers. There used to be a lot of oil coming out of the cam cover breathers but with the changes I have made (1mm restrictors and sump breathers) that is now minimal (insignificant).

Each catch can is vented to atmosphere through a Moroso breather cap. This arrangement is illegal in NZ unless you have a cert and are a member of a car club and have a competion licence and a log book. I can comply with these conditions but would like them not to be vented to atmosphere so I will run the cam cover hoses to the same 2L catch can as the sump breathers and then run a hose from the very top of the catch can (where the vent is currently) to another catch can which is definitely an oil/air seperator. That I plan to vent to the intake. I do not expect significant oil vapours etc to be in this after going though two catch cans and so it will not be a negative factor in the tune. If I am wrong I will revert to venting to atmosphere ...although I note some of the Japanese competition cars seem to do this ok (run 2 catch cans in series and vent to the intake).

The advantage? Well I could say I am saving the planet but in reality I am more concerned about the smells that waft in through my aircond as this is my daily as well as my race car!

[r33_racer]

KiwiRS4T - Is there any baffling or gauze inside your catch can with the crank case breathers plumbed into it? Or does the venting blow by pressure have clear access straight to the moroso breather cap?

[KiwiRS4T]

KiwiRS4T - Is there any baffling or gauze inside your catch can with the crank case breathers plumbed into it? Or does the venting blow by pressure have clear access straight to the moroso breather cap?

There is no baffling at present as I have been experimenting to see what works. Mind you I don't believe there is too much to baffle as the pressure coming out of the sump is not so much blow-by (my leakdown tests confirm this) but I think it is the action of the crank that stirs up a storm!

I will have some metal internal baffling on my permanent set up and definitely the second catch can will be properly baffled.

[The Bogan]

This is what we did to stop and oil splattering around and coming out the vents, a perferated baffle plate was installed and pipe was put in to stop the oil having easy access when the oil pushes to the side under high cornering load, stainless wool was placed at the lower section to stop the oil having a easy path.

It seemed the only track that made it spit oil was Wakefield, being a left handed track the oil in the can on hard right hand corners would slosh to the side ond spit out.

Ive also installed RB26 covers with the Mines baffles.

10/40 oil ATM

Im going there tommorrow, lets hope it fixes the problem.