1st, I did a search under "Melling pump" and I read most everything on this subject.

Here's the deal - I have a 2001 C5 Vette w/ the LS1, 25,000 miles - stock bottom end - I did some performance mods such as G5X3 cam, Caddy racing lifters, AFR 205 heads, Melling 10296 oil pump, Cloyes timing chain and gears, underdrive pulley

When I installed the Melling pump, I left the RED spring in it - my oil pressure is as follows - oil temp of 203 - 207 degrees (45 minute highway drive)

idle 58 - 63 PSI

2500 RPM 65 PSI

3000 RPM 71 PSI

I can EASILY get 74+++ PSI if I step on it - in fact, on Easter Sunday, I hit 99PSI at 4,500 - 4,800 RPM's

I'm of the belief that my oil pressure is SERIOUSLY too high - I've talked w/ Melling directly, and they also think my oil pressure is too high - I'm returning the pump for inspection, and I've ordered a replacement Melling 10296 oil pump to install ( don't ask about Melling pump warranty - I get credit when my vendor get's credit is the story)

My plan is that when I install the 2nd Melling 10296 oil pump, that I will use the BLUE spring this time - but I'm wondering if the COMBINATION of the Caddy racing lifters and the Melling oil pump is TOO much, and causing too hight of oil pressure?? Anyone running the two, and what pressures are you seeing??

Also, what oil pressure is TOO high of an oil pressure at WIDE OPEN THROTTLE - tell me what PSI my oil pressure should NOT go over, especially when I hit redline which I estimate will be about 6,800 RPM

I'd like to run the Melling pump, but it's a Pain in the AZZ to install / reinstall the oil pump in a C5 LS1 Vette, so I'm looking for some advice

Reassure me that I will or will not have a decent oil pressure if I use the BLUE spring on a Melling pump - and again, do the caddy racing lifters make any difference???

 

A good rule of thumb is 10# per 1000 rpm at operating temperature (~195* or so).