My new 383 solid rotor motor is getting pretty low oil pressure. Well it is low to me as my old motor had high pressure.

I am using regular dino oil 20w-50.
At cold idle i get around 50-60 psi.
At hot idle (after crusing around) about 25 psi
At hot ide (after going threw few gears) about 21psi
At 2000 rpms around 38-40 psi
At 3000 rpms around 50ish psi
Anything over 3000 rpms gets little bit more then 55psi

I am using moroso racing oil pump (blue printed with anti cavitation slots) with a GM white spring. From what i have been told the anticavitation slots decresses the oil pressure at idle. Anyways, what can i do to bump up the pressure a little bit? Or is the pressure i am seeing planty. What worries me the most is, after few hard passes the oil pressure drops about 5psi, so its most noticable at idle. Will using a better (synthetic oil) help that? What about going with straight SAE 50 oil?

One more thing, under hard braking the oil pressure sometimes drops bellow 20, i know my pick up is set right as i did it few times now, and its pretty much sittin on the bottom on the pan. I am using a stock oil pan with a diamond scraper windage tray. Any ideas why would the pickup become uncovered with my setup?

The motor has about 2k on it and the pressure been the same since the first start up. Let me know what you guys think.
Thanks
Marcin

 

Why do you want hjigher oil pressure? Sounds fine to me except hard braking. You can try running it a little fuller or get a better pan. It sounds like you are briefly uncovering the pickup.

Rich

 

It may be that your pressures are a little low, considering that you're running 20W50, but that might be because of the anti-cavitation grooves. Some people like to see 10psi oil pressure for every 1000rpm, and some people are happy with very little oil pressure. Do you know what your clearances are? Do you have an oil temp gauge?

It sounds like the GM white spring and Moroso pump combination has a relief pressure of 55psi. When the pump is producing more than the relief pressure, the spring compresses enough to uncover the relief port, and some of the oil gets pumped back into the sump. Kinda like a bypass-style fuel regulator setup. (So if you want more peak pressure, install a stiffer spring.)

I personally wouldn't worry about losing 5psi after a few passes, but a synthetic might help a little if that bothers you. However, 20W50 and straight 50 should behave pretty much the same once they are at operating temp.

It sounds like the oil is sloshing forward in the pan under hard braking. Like Rich said, a higher oil level might help, or you might have to get a better pan.

 

A few questions...

Why the 20w-50?
What are your clearances?
What oil filter are you using?
Stock pan or aftermarket?

-Mindgame

 

Ya need an after market pan with trap doors and a solid baffle You will have to get a pickup to match the pan too. The baffle keeps the oil in the sump under braking.
Ya can try 30to40 weight Kendal GT-1 and see if it helps.
When ya change the pan look at the brgs to see if there is any damage from oil starvation while braking.

 

My low pressure warning switch is 15 psi. As long as pressure doesn't drop below that, I'm not worried.

A windage tray doesn't stop the oil from going forward in the pan under hard braking. If you're hard on the brakes enough to be worried about the drop in pressure from the oil moving away from the pickup, install a Moroso oil accumulator into the system. It will feed oil back into the galleries if the pressure drops too low.

 

Pan baffles/trap doors are what stops oil from sloshing away from the pickup under braking. No one said that a windage tray does that, did they?

Rich

 

What kind of oil pan do you have on there?

 

do you have any kind of oil cooler on there, or by chance an oil temp gauge? because that might explain part of your pressure drop when you've been beating on it.

 

I'm going to try and fit an accumulator on my new engine (that I'm building)- i like that idea if I can find a place to put it - I'm thinking along a subframe connector if it doesn't stick down too far.

 

Yeah..............uh..................grilled cheese.........duh.........?

 

Huh? Maybe it's a dumb idea and I just threw it out there, but im just out of places to put anything else on that car.

 

As long as you get an accumulator with a piston in it, you can mount it any way you wish. Even upside down.

 

As others have already said; you have plenty of oil pressure.


I'm going to go against the grain here and say that I'm not convinced that you ARE uncovering your pickup.

Certainly, getting a better oil pan is worth it on it's own merits.

However, if you were truly uncovering your pickup, your pressure would most likely dive way further south than merely "under 20".

It is theoretically possible, although unlikely; that your crankshaft shifting forward a few ten thousandths affects your pressure.

I would think it is far more likely that the sudden G forces either affect your gauge temporarily or perhaps your ability to read it accurately due to the sudden movement of your head. Perhaps both. Perhaps a parallax issue...

But seriously...
An uncovered pickup can often be sufficient to cause your idiot light to flash. That's a lot lower than 20psi.

Not that it COULDN'T be happening, so get the pan anyway. I just don't think it's the most likely explanation.

FWIW...

 

You mean... like pushing in a clutch?

You ever seen a drop in oil pressure from that??

Oh good.

What if it's just partially uncovered?

FWIW, they don't always drop below 20 psi when partially uncovering the
pickup.

Of course, I think this thread is pretty much dead considering the thread starter has pretty much abandoned it without answering a single question.

-Mindgame