rb26 Oil pressure woes

[240zdan]

So I am super paranoid about my RB26 oil pressure it being a r32 motor with stock bottom end.
I really dont want to tear into the motor just yet, I would like to replace more than an oil pump/collar to make it worthwhile.

So anyways, I just did an oil change to Castrol Edge 10w-30 oil. We have been getting fairly cold temps here lately (0 degrees celsius) so thats why I choose the 10w30. Normally in the summer I try to run a good 50, or even 60 weight oil, which does seem to up the pressure a bit more. But the manual calls for 30 weight oil, and these are the values I get with a cheap mechanical gauge after a long street drive. (the electric guage shows similar values)

idle (950rpm): 17psi
2000rpm: ~36psi
3000rpm: ~50 psi
4000+rpm: 70 psi+

Now these numbers seem a bit low to me. The motor runs great and doesnt knock or anything, I have been running it like this for about 2 years. I have been avoiding the rev limiter as much as possible and do not spin high RPMS (under 7500rpm)

The GTR manual calls for :
idle: 21psi
2000rpm: 3 bar 45psi
3000rpm: 4.5 bar 60 psi

Should I stop worrying? Should i change to a 50/60 weight asap?
What do you guys usually get for oil pressure numbers (I know a tomei or Jun pump will spit 30 psi at idle, not really interested in aftermarket pump values, just oem values with higher kms motors)

[GodziRRa]

Well seems just a bit low from normal. Try swapping w/ a thicker oil and then check. Actually, most GT-R owners I know use heavier oil like 15W50, whether in Japan or outside Japan. Anyways, it may also be a sign of the early 90's engine wearing out. Is your engine not yet rebuilt? How many mileage has it got already?

[240zdan]

I have no idea how many kms on it. I know a rebuild has to come sooner then later but Its not the right time for me right now. At the same time I dont want to be paranoid about driving the car.

I think a heavier oil is the solution. I had decent oil pressure with 50weight oil that was much closer to factory specs.
What oil do you guys reccomend. I was using mobil one 15-50 before.

[240zdan]

whats better to use 15-50 or 10-60

[GodziRRa]

Me I already have my Motul 300V Competition 15W50 here. Just going to put it after my engine break in.

By the way this is a good example of what GT-R owners use for their oil (borrowed from another site) - http://www.gtr.co.uk/forum/32925-wha...r-skyline.html

[Skym]

From what I understand, depends on alot of things like oiltemp, age of engine, environment, application.

Read this document from UK oil specialist -

http://www.opieoils.co.uk/pdfs/tech-articles/10w-60-oil.pdf

Their website (read technical articles near bottom of page) -

http://www.opieoils.co.uk/

I gather factory run thinner oil for road use, as oiltemps are not as high, clearances on bearings are tight. Nissan dealership said to change the weight of oil as the engine ages. Makes sense as the bearing clearances, etc get bigger as engine ages.

So would need to talk to Nissan Dealership, tell them the km of engine and ask what oil they use at that amount of km (helps as a guide on what works).

Then note your oiltemps your engine encounters (oiltemp gauge in centre console) and read 10W60 oil article above and make a informed decision on what oil best suits your engine. May take a few tries, but should work it out.

Or ask Opie oils and supply oiltemp, mods, etc -

http://www.opieoils.co.uk/frmRecommendAnOil.aspx

Castrol Edge Sport 10W60 last's 35 laps in a 330hp at engine R32 RB20DET without engine oilcooler before it had bearing failure.

[240zdan]

thanks for the links guys