240z4u

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903 posts
Madison Wi
2-21-2005
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| « Re: Oil catch can filling up at the track... y? (gawdzilla) | 9:04 AM 7/15/2008 |
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For what its worth, I think your on the right track. Something heavier would be worth a try. Can't imagine another reason why it would be happening unless you have way too much oil in there!
RB25DET SII, T3/T04E, Power FC, 650cc injectors, new pump, aeromotive FPR, 3" dp/exhaust. FMIC, Z32 maf, Home Depot MBC, Tial external gate, forge motorsports BOV, Methanol injection, custom intake manifold, modded and coated stock exhaust manifold.
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gawdzilla
Online
1595 posts
none
9-18-2004
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yea... i think the oil is just getting moved since its a high pressure to low pressure difference, and the oil itself doesn't have much weight to settle out of the valve cover baffling fast enough
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Darius

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2847 posts
'97 240SX SE
Ames Iowa
3-2-2003
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| « Re: (gawdzilla) | 10:42 AM 7/15/2008 |
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When I was street tuning last summer on a cool muggy morning, my catch can filled almost half way up with oil and water vapor. 50/50 mix. Just be careful if you have a breather filter on the catch can and there's that much vapor going through it, because it will plug and the crank case will pressurize. The exhaust will start smoking like crazy from the blowby.
 Former Vice President of the NRRBA - Non-Running RB Association Join today! Temporary and Lifetime memberships available.
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gawdzilla
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1595 posts
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9-18-2004
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| « Re: (Darius) | 11:01 AM 7/15/2008 |
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| Quote, originally posted by Darius » | | When I was street tuning last summer on a cool muggy morning, my catch can filled almost half way up with oil and water vapor. 50/50 mix. Just be careful if you have a breather filter on the catch can and there's that much vapor going through it, because it will plug and the crank case will pressurize. The exhaust will start smoking like crazy from the blowby. |
i've had that happen once when i was running just breather filters on top of the valve covers. they got soaked in oil and clogged and i got huge white smoke clouds out the exhaust.this time it's different. just getting a lot of oil in the catch can but i'm pretty certain its not an indication of exessive blowby or worn rings
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Darius

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2847 posts
'97 240SX SE
Ames Iowa
3-2-2003
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| « Re: (gawdzilla) | 2:14 PM 7/15/2008 |
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I am curious to know if there's enough oil built up in the head under hard acceleration that upon heavy braking (corner at the end of a straight) there's enough oil to slosh to the front of the head and around the baffles to the valve cover outlets?? I'm trying to throw out ideas here even though that might not make any sense with the way the baffles are set up. I noticed when I cut open the stock valve cover vent line that comes from the RB25 vertical fitting that there is a little metal puck with a 1/8" hole in the center of it. Do you know if the RB26 had something like that?
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gawdzilla
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1595 posts
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9-18-2004
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| « Re: (Darius) | 2:22 PM 7/15/2008 |
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its hard to say how the oil is travelling around under the valve cover. since i didnt do the head restrictor or the real head drain mods, maybe my head is filling excessively with oil. i highly doubt it is to the point that each valve cover is ENTIRELY filled because that would leave no oil in my sump. there is probably just a fair amount of splashing and since the oil catch can and breather are lower than the height of the valve covers and also low pressure compared to inside the valve covers themselves... oil is probably being squirted out from high to low pressure, as well as siphoning out from gravity and the pressure difference. that's my only explanation... ive never had (or looked at) the factory breather lines so i don't know if there is a restrictor in them.
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gawdzilla
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1595 posts
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9-18-2004
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ordered the mines triple flow cam cover baffle plates. i'll post up about how they do.http://www.mines-wave.com/engl...E.htm
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KUILLIN_DRIFTER

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1000 posts
OWN S13.5 RB25DET
san antonio tx
4-14-2004
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| « Re: (gawdzilla) | 8:41 AM 7/20/2008 |
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great find. I never really put any thought into the oil head drain mod. But i see now how important it is. Its impressive to see most known tuning shops have addressed this issue and have a product for it. I feel like were always behind the power curve here in the u.s.
89 HB RPS13 RB25DET ECR33 Apexi FMIC/HKS BOV RECIRC
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Rare_f8

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455 posts
1990 300zx 2+2
Omaha NE
10-7-2007
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| « Re: (gawdzilla) | 9:43 AM 7/20/2008 |
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how much you get your tri baffle plate for? n1 valve baffles are longer than stock.I do like to hear more about your oil weight theory/experiement. I am not a fan of the rear drain mod. Nissan never thought it was an issue hense.. not doing anything to the past 12 years that the gtr was out. I do instead gasket match the oil return between the block and the head. If you are using a modified gtr oil pan, there's traps in the oil pan with tiny drain holes to drain the oil out, I enlarge them to let more oil drain. I am still working out a oil return baffling on the oil pan, still in planning stages.
Modified by Rare_f8 at 2:27 PM 7/20/2008
All Work, No Play, Make Rare Dull Boy
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HxC_Nismo
Original? Creative? Eh.

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512 posts
98' Nissan 240sx SE R33 RB26DETT
Hallsville/Columbia MO
9-23-2006
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| « Re: (Rare_f8) | 1:50 PM 7/20/2008 |
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+1 where did you buy em from?
   -Hans- 98' 240sx SE R33 RB26DETT HKS GT2530 467RWHP 334RWTQ @22psi http://www.midwestce.net
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Blown240sx
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1708 posts
1996 240sx
Bowling Green KY
4-21-2005
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| « Re: (HxC_Nismo) | 4:00 PM 7/20/2008 |
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Are you blowing by that much before over filling or after? Over filling is going to cause some blow by issues also.If you have excessive blow by hook a hose to one side of the catch can going to the intake hose and another to the head and the suction should draw a lot of the crank pressure out reducing blow by.
1990 240sx (RIP) 1989 240sx (sold) 1996 240sx 408ci V8 (sold) 1972 Datsun 240z LS1-T project (in progress)
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gawdzilla
Online
1595 posts
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9-18-2004
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| « Re: (Rare_f8) | 7:19 AM 7/21/2008 |
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| Quote, originally posted by Rare_f8 » | | how much you get your tri baffle plate for? n1 valve baffles are longer than stock. I do like to hear more about your oil weight theory/experiement. I am not a fan of the rear drain mod. Nissan never thought it was an issue hense.. not doing anything to the past 12 years that the gtr was out. Modified by Rare_f8 at 2:27 PM 7/20/2008 |
got the tri baffle plate for $287 shipped from rhdjapan. like $260 something if you go overseas mail but id like to install them before an event in august. not the cheapest thing, but it's Mine's. I think the retail price is around $200-220 w/o shipping. yea the n1's are longer than stock but i figured it would be harder and slower to get those than the Mine's parts.not a fan of the rear drain mod myself either... but that's just my opinion. | Quote, originally posted by HxC_Nismo » | | +1 where did you buy em from? |
rhdjapan| Quote, originally posted by Blown240sx » | | Are you blowing by that much before over filling or after? Over filling is going to cause some blow by issues also. If you have excessive blow by hook a hose to one side of the catch can going to the intake hose and another to the head and the suction should draw a lot of the crank pressure out reducing blow by. |
it doesn't seem to be affected too much by the overfill. i have my oil usually filled to the first hump on the dipstick. maybe .5 qt over the high mark. on street driving (with occassional WOT runs but not back to back like the track), my catch can BARELY fills. literally 3-5 drops of oil after weeks with about 30 drops of moisture on top. i can see how overfill might affect drainback into the pan because theres more oil normally in the sump maybe partially blocking the gravity returnsi think hooking a hose to create more suction out of the valve cover will make it worse. oil is getting caught between the blowby gas and the valve cover exits. if there is a vacuum it will just suck the oil and blowby gas out faster. if you take a look at the Mine's diagrams, the light blue is the blowby gas sitting behind the yellow oil. Once oil reaches the valve cover exits, it seems the blowby gas is just going to push it out. the idea behind the baffle plates is to keep the oil from getting to the valve cover openings. In theory it seems like a good idea, so i'm giving it a shot
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Blown240sx
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1708 posts
1996 240sx
Bowling Green KY
4-21-2005
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| « Re: (gawdzilla) | 9:53 AM 7/21/2008 |
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Just saying though that a build up of pressure in the first place could cause the blow by. IDk I figured a 3 dollar hose was worth a try before spending more.
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gawdzilla
Online
1595 posts
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9-18-2004
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just a followup. i put these in and they WORK. install was pretty straightforward and of course fitment was perfect as i expected. blowby has been reduced from about 16 oz of oil over 20-minute track session to about 2-3. i'm pretty happy with the results
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Shocker

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1637 posts
Youngstown Ohio
8-1-2004
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| « Re: (gawdzilla) | 6:12 PM 8/18/2008 |
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| Quote, originally posted by gawdzilla » | | just a followup. i put these in and they WORK. install was pretty straightforward and of course fitment was perfect as i expected. blowby has been reduced from about 16 oz of oil over 20-minute track session to about 2-3. i'm pretty happy with the results |
Nice to know Gawd, too bad they dont make one for the 25 cover's.
RETIRED NRRB Since 3-17-08 RETURNED to the NRRB 8-9-08
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SullivanRacing06

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110 posts
1991 S13
Gainesville Fla
4-21-2007
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| « Re: Oil catch can filling up at the track... y? (gawdzilla) | 11:48 AM 8/19/2008 |
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i run rotella 15-40 oil all the time, i had the same issues w my greddy can filling up, sorta sucks to see but that happens with righ revs and boost on any motor
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