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lol Joel, you redeemed yourself with that last line :)

seriously Damo, unless you've done what Joel and others have done in relation to baffles and restrictors, do not try this method.....2 laps around Malalla and they'll be full.

I still believe that the 2 can setup that I described earlier is still the best for no other mods to restrict the oil

+2 for the two can system if you havent done your internal oil mods..

It worked well for my GTR and I took it to the track all the time and was doing quick times.

I still overfilled the oil a litre and half as well.

Your always going to get a bit of oil in the 2nd can if your pushing the car and out in it alot..as long as you top up the oil you will be right ;)

  • 2 weeks later...

I decided to fit an oil catch can before i went to Mallala on Sunday, just one of those cheap ones from ISC. This is how much oil was in it after just one day at the track.

post-51334-1238412041_thumb.jpg

Edited by DSTROY

No baffles, and yes i did overfill. Filled it to the top of the H on the dipstick and i tried not to rev past 7000rpm but i hit the limiter at 8000rpm a few time when the wheels decided to spin coming out of corners in second gear.

If the catch can fills up with oil after a few laps, what would it indicate? Severe blow-by? Or just incorrect setup?

They all pump oil out when at high revs from the head as the oil cant drain to the sump quick enough. Mine used to fill up after a full day at the track

Depends on how big the catch can is to get concerned??Thst why I like the two can system one mounted ontop of the head and breathers going to a seond can situated near my headlight

If the catch can was filling up with general driving thats blow by :wub:

If the catch can fills up with oil after a few laps, what would it indicate? Severe blow-by? Or just incorrect setup?

It can be due to a number of factors, the most common being.

1 Incorrect set up. Mostly this involves people removing the pcv function which allows the sump to be pressurised which in turn causes problems. Make sure the pcv is fitted & working - this can be done even when a catch can is fitted.

2. Oil in the head splashing/generally finding its way into the recirc system. This is common on RB26's particularly. The popular conception is too much oil pumped is into the head - but it is just as much a function of poor shielding for the venting system. It can be fixed by oil restrictors (head off), oil return lines (engine out - mostly), Mines cam baffles (see below!) or oil/air seperators like the Nismo offerings (Stupid money for what you get). The principal advantages of these systems over catch cans is the are either hidden from view or look stock. Which means one less potential point of grief from the police. There are other offerings as shown in this thread but they tend to stick out like dogs b@llocks.

3. Blow by.

  • 5 months later...
Pete,

Another mod is to relieve/vent the pressure in the sump to a catch can. Also works as a catch can drain if needed which it won't. :D

Where can this connection to the sump be made on an RB25? Could you just T-into the turbo oil return line? Also would it need a PCV valve?

It can be due to a number of factors, the most common being.

1 Incorrect set up. Mostly this involves people removing the pcv function which allows the sump to be pressurised which in turn causes problems. Make sure the pcv is fitted & working - this can be done even when a catch can is fitted.

2. Oil in the head splashing/generally finding its way into the recirc system. This is common on RB26's particularly. The popular conception is too much oil pumped is into the head - but it is just as much a function of poor shielding for the venting system. It can be fixed by oil restrictors (head off), oil return lines (engine out - mostly), Mines cam baffles (see below!) or oil/air seperators like the Nismo offerings (Stupid money for what you get). The principal advantages of these systems over catch cans is the are either hidden from view or look stock. Which means one less potential point of grief from the police. There are other offerings as shown in this thread but they tend to stick out like dogs b@llocks.

3. Blow by.

PCV valve has almost nothing to do with it. The PCV valve only operates when there is negative intake manifold pressure, so unless you have a N/A it is closed apart from off boost... The factory system utilities a passage from the breathers to the intake before the turbo which allows the vacuum from the turbo to continuously pull from the crankcase.

The main thread has better details, no point going over it again in here.

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