Oil pressure @ performance?

[Alan Roehrich]

Danny, I can't say exactly with your 283. But with our 427/425, changing from the 50W Joe Gibbs BR oil, to Joe Gibbs XP-2, we can gain over a tenth, easily, with about the same oil pressure drop as you describe.

It might help a 283 even more, since it has less HP "to spare".

That's probably what I would try, find a light, but not too light, synthetic oil, make a couple of passes, and then change from your current oil to the new lighter synthetic.

[Bub Whitaker]

Allen, that's not the question, he wants to know same oil, lower pressure via bypass to lower pressure, what is the gain?

[Alan Roehrich]

Originally Posted by Bub Whitaker

Allen, that's not the question, he wants to know same oil, lower pressure via bypass to lower pressure, what is the gain?

Bub,
I understand that. What I'm saying is, the best way to get some idea of what gain can be had, without taking everything apart and spending a fair amount of time, is to try a really light weight oil.

Sure, the difference in friction between the oils will have an effect, but not as much of an effect as the reduction in HP spent turning the pump.

Once he sees what using the lighter oil will do, then he can look at what he needs to do to run lower oil pressure without risking damage. He'll probably gain even more power, and be pleasantly surprised.

[danny waters sr]

I am changing the oil pressure now and still run cam -2 blue blood oil 5w-30..
Will run it at VMP this weekend and see how much diff it will make.
I hope you all are right as i would like that kind of a surprise...
Let you know monday the results....

Thanks again...

[Kenney Kelley]

Danny this might be some help. http://www.superstockforum.com/showt...threadid=11549 Kenney Kelley

[Tom Meyer]

Danny you have PM

[Ed Wright]

Originally Posted by Kenney Kelley

Danny this might be some help. http://www.superstockforum.com/showt...threadid=11549 Kenney Kelley

I have one of Larry's low volume pumps in my SS LT1. I set the relief spring to 40 psi. 40 psi @ 8500, cold idle is also 40, hot idle is 20 to 25 psi with 5W 20. Bearings always look like new, except for one time I tried Joe Gibbs zero wt. Saw some wear on 4 rod bearings. Won't try that again. Zero-5 (Used to be called "Race9") Royal Purple does just fine. I've never used over 40 psi through the lights. Used to use 30 psi in my Stockers. You have to have everything else right. Even with this pump the Royal Purple was worth 12 hp on the dyno.

[Joe Schaechter]

Here is another low drag pump option for a small block Chevy

http://schumannsdynamicperformance.c...43/SBC/LVDR5/8

[Pvt Parts]

Originally Posted by Alan Roehrich

Bub,
I understand that. What I'm saying is, the best way to get some idea of what gain can be had, without taking everything apart and spending a fair amount of time, is to try a really light weight oil.

Sure, the difference in friction between the oils will have an effect, but not as much of an effect as the reduction in HP spent turning the pump.

Once he sees what using the lighter oil will do, then he can look at what he needs to do to run lower oil pressure without risking damage. He'll probably gain even more power, and be pleasantly surprised.

Triple XXX Correcto !!!! Doing that reduces the HP necessary to turn the pump and the improvement in lubrication reduces the parasitic drag. And your forgot to mention that with improved lubrication, you can probably get by with less oil in the pan thereby reducing windage.
Unless he's saying he has those pressures with 0 wt oil now. In that case, take it apart.

[rod]

in the newest Car Craft mag, in the 'ask anything' Q&A section there is a letter/answer about just this very thing. also there is a reference to a previous oil pump test.
even a 1 horse change in a 283 will make a difference whereas a 1 horse change in a 427 is almost unnoticed, speaking percent wise.
rod in AZ