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What is too high for oil pressure?


Thumper

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Ok I installed a new turbo/automatic oil pump into my z. I also have the competition inner and outer springs in it. The oil pressure while cold or even after sitting in my driveway awhile will go up past 80psi. I stop the rpms when it goes this high. I am about to take a slow drive and see if after a few miles the oil gets thinner and oil drops.

 

 

I was wondering what would be TOO high for oil pressure? I know too much is bad for seals so my guess would be 55psi max. Thanks.

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What kind of oil are you using? If you are where it is cold (below 40`), most standard oil will run up to 90# of oil pressure, cold. I used to race a BMW/Chevron and the oil pressure relief valve would stick (100+) and the oil filter would expand and start to leak. I do not feel the L6 turbo pump will put out more than 90#. Once you get a little temp in your oil it will start to thin out and your pressure will run at 50-55#. Just keep it under 3000 when you first take off and it will be just fine. Your seals really do not have any oil pressure on them; Only crankcase pressure. I run Mobil 1 because of the lower viscosity charactoristics. If high cold pressure is a concern you may want to convert to a synthetic. (If the car has been rebuilt within the last 8-10 years)

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With a comp pump I could peg my Autometer pressure gauge when cold. I took out the outer comp spring and now it's not so bad when cold. It won't peg the gauge anymore like it used to. Generally speaking the rule of thumb is 10psi per 1000 rpm. With the one comp spring that's about what I get, but it gets to max pressure by about 3500 rpm IIRC. Scary. It's been so long since I've driven my Z I can't remember... :icon50:

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Well I drove the car around for about half an hour and by 3500-4000rpms the pressure would be at 70-80psi. I never took it above that. So I swapped in the stock oil pump spring and all is good. By 3000rpms 50psi by 3500rpms 56psi and it stays there intill redline. I am sure that after a week of driving both the oil pump and oil will lower the pressure. I am running 10w-30 mobil 1 and its 80+ plus here so that was not an issue.

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I was running an n/a oil pump out of a 260z motor with the comp springs and the oil pressure was a good 10-15psi lower than the turbo/automatic with stock spring pressure. So that tells you how much more the turbo oil pump flows. Plus my top-end feels stronger (hydraulic lifters), and my turbo spools a tad quicker. My oil pressure b4 was 38psi at full throttle and now it is 55psi.

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  • 1 month later...

on the opposite side of this thread... how low is too low?

 

sometimes while cruising at just under 3000rpm, my oil pressure will be around 25-30psi. I notice this only happens once the engine is up to full operating temps. I run 10w-30 synthetic. Unless that is normal, I'm going to try 10w-40 for the next oil change and see if anything gets better.

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on the opposite side of this thread... how low is too low?

 

sometimes while cruising at just under 3000rpm' date=' my oil pressure will be around 25-30psi. I notice this only happens once the engine is up to full operating temps. I run 10w-30 synthetic. Unless that is normal, I'm going to try 10w-40 for the next oil change and see if anything gets better.[/quote']

 

Hey olie if you want I have some competition springs from Courtesy. With the turbo automatic oil pump it was too much oil pressure but when I ran my n/a oil pump it was perfect. I have both the inner and outer. You can swap the springs without taking the oil pump off so like 5 minutes. Let me know if you want them.

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I'm about to swap in a new turbo oil pump with comp springs... I have a feeling the comp springs are going to be too aggressive (I have stock internals and stock oil pan, and I'm adding a slightly shaved, port and polished head with a fatter cam and custom intake on top)..... and my question is.... where can you get the standard springs? I looked around and Courtesy Nissan only seems to have the comp springs for sale and I can't find a vendor who sells the standard ones... I'd like to pick up the standard springs if the oil pressure's too high (having a feeling so)..... shoulda done my research first, but got a bit anxious in during the parts buying phase... sht happens...... anyone know who's got the standard springs for sale? Hope to get all these mods (and a couple others) in place overr the next several weekends.... then I'll mess with Megasquirt and turbo injectors......... right now I'm like a lil kid on xmas eve

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I posted my reply and then had a thought... does the na stock pump in a 81 280zx use the same two springs as the turbo oil pump? Can I take the springs out of my old na oil pump and put them in my new turbo oil pump, in place of the new comp springs it came with? That would be a great option... just didn't know the compatibility of the two... thanks for reading my two overly-descriptive replies... just wanted to be clear

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I posted my reply and then had a thought... does the na stock pump in a 81 280zx use the same two springs as the turbo oil pump? Can I take the springs out of my old na oil pump and put them in my new turbo oil pump, in place of the new comp springs it came with? That would be a great option... just didn't know the compatibility of the two... thanks for reading my two overly-descriptive replies... just wanted to be clear

 

Yes you should but there is only a single spring in the oem oil pumps. No inner and outer.

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Just an FYI for my buildup the competition inner spring and the fatory outer spring gave me the best combination. Like Jon, it's been awhile since I've driven mine so I don't remember the exact #'s. This really seems to be a matter of each indivdual engine needs to be fine tuned to find the right set up.

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This might be a bit old school but in a few of the Z's I had in the past that I installed turbos on, well I placed some small washers the size of the stock oil pump spring and placed them behind the spring. This increased the oil pressure just right and allowed a good fill on a gravity feed oil can that cooled down the turbo bearings after the car was shut off. They did this on many of the old IMSA style Z cars including both Bob Sharp cars. This solution did not seem to over work the spring and kept it inside the 80 to 20 percent working range which is perfect for springs. Also it is a very cheap fix.

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Just an FYI for my buildup the competition inner spring and the fatory outer spring gave me the best combination. Like Jon, it's been awhile since I've driven mine so I don't remember the exact #'s. This really seems to be a matter of each indivdual engine needs to be fine tuned to find the right set up.

 

I'm going to try that.... I'm swapping the oil pumps now... keeping comp inner and the old standard on the outer.... I'll follow up and report how I make out... could be awhile before I fire her up... still got lots of work to do... thanks for the tip!

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