OIL Dillema

[240slidekat]

alright im almost fed up with this motor, heres the dilemma

during cold start, the oil pressure rises like normal, rev it, it rises, normal. alright then after driving the car a bit i noticed that my oil pressure drops pretty bad, then when i would let off of the throttle my oil pressure is at 0! and my oil light would come on/or flash then when i step back on the gas my oil pressure would go up but not high enough to be normal. lets say im at 3000rpm and my oil pressure is at 10-15psi.thats pretty damn low considering the general rule of thumb being 10psi for 1000rpm.

i have a brand new n1 oil pump and i have the oil pump collar. for those people that think is the gauges, i have 2 gauge, 1 the r33 gauge cluster and 2nd autometer oil pressure gauge, and i also have a blown turbo to prove that its not the gauges. good thing for turbonetics has a killer warrantee.

the only thing i can think of is that the set screw that holds the collar in place against the crankshaft broke and therefore the oil pump is not getting a good grip on it? what do you guys think? any other possibilities out there that can be check? im soooo close to blowing this car up for 4th of july finale.

[takaramotors]

that is why with the jun crank collars the machine shop should really weld it on and then run the screws.

[Darius]

Not to ask a dumb question or anything, but are you running a restrictor on the oil feed line to the turbo?

There is apparently something very wrong with your oil pump, with the oil pump drive, or the oil supply line upstream of the gauges. Since it's purely mechanical, something is physically wrong with the system and your gauges and blown turob have verified it. Time for tear down.

[98birdls1]

I wasn't aware a restorictor was neccessary on the turbo oil feed line? Are you talking about the restrictor needed in the block to keep the pump from overfilling the head and draining the pan?

It seems that could be a likely canidate. But I was only aware of this happening in mostly high rev cases, not daily driving.

As far as I know a 1.5mm restrictor is needed in the back oil feed and the front one is suppose to be blocked off, from what I have read.http://www.tomei-p.co.jp/_2003....html

If anyone has any extra info post up. Also if anyone can find a vaible place to buy these restirctors let me know. I need them

Luke

[Darius]

A restrictor is required on the turbo feed line to keep pressures in the turbo in check. Otherwise it puts extra wear and tear on the oil seals in the turbo leading to premature failure. Installing an aftermarket or upgraded oil pump will most likely increase pressure and flow. Can someone fill in what the pressure should be?

I have never heard of the tomei oil restrictor for limiting oil supply to the head but that seems logical with an upgraded pump. I wouldn't think that the oil would build up in the head since it's gravity drained and extra oil flows back down to the sump. Either way I found it on Greenline Motorsport towards the bottom two-thirds of the page. Looks pretty inexpensive too.http://www.greenline.jp/catalo...ngine

[98birdls1]

I've never heard of the oil problem for turbo's but I'll look into it. That seems like something easy enough to do while the motor is in the car.

Here's a good link for the oil restrictors in the block, which would require the motor torn down.http://www.skylinesaustralia.c...ctorsThe table is very informitive.

Luke

[Darius]

Here is the table that 98birdls1 is referring to:

[98birdls1]

Thanks for the table.

Apparently Matt and I are the only ones interested in this? Carl H, I noticed you posted in that thread, care to add any enlightenment??

Luke

[Darius]

Maybe I'm asking a dumb question here, but in that table in my previous post there are two columns for the RB25...one without VVT and one with. I thought all RB25's Series 1&2 came with VVT on the intake side? Anyone have any ideas as to what the differences are in that table?

BTW I bought three 1.5mm Tomei oil restrictors because I figured someone would be interested 98birdls1 and they are shipping tomorrow, so I can let two of them go. $11 shipped.

[98birdls1]

I believe the R34 Neo motor does without the VVT if I'm not mistaken. Someone please correct me if I am.

And Darius, thanks for looking out, I will definately take one off your hands. Give me your paypal addy, or some other way to make payment.

What are you doing for bearings. I don't know if you saw the post about King bearings, but Jim @ Cumpulsive HP is helping me source alot of my parts. Good guy, and great to work with. I believe he is looking into a sponsorship of Nico. May one to check it out.

Luke

[Carl H]

as stated in that thread lots of good points have been made about the oiling system.when i get my motor back together (which will be within a week or so...) i will have had a few mods done to the oiling system.info is out there for sure just have to know how to intepret it .

[gawdzilla]

what weight oil are you guys using? i'm thinking about getting some heavier oil for the summer time myself so am curious.

also the collar thing shouldn't have an affect on your problem.. pretty much if the collar slips its done for good. its not an intermittent problem like you describe.