Dyno next week!

[Ironmike]

Man, I just can't make up my mind. Wasn't happy with 62psi oil pressure, priming cold, so I ordered the MP high pressure spring. Got it today and found out that it is indeed the standard spring installed in ALL Melling Mopar oil pumps. My pump is the standard volume Melling M72 and comparing the 2 springs, they are identical. Same height, same number of coils and same wire diameter. So... I decide to shim it with a .050 washer. Throw it all back together, dump the oil back in and prime it.

Using the same 2500RPM drill I got 78PSI. As OldmanRick stated,"we'll never know for sure how fast that drill is really turning", (I thinks he's right), That's roughly 5000RPM engine speed. So I figure I'm GOOD!

Then the buddies start yappin', and making me think too much......so now I'm worried I might fire the thing up and see 100PSI or something at 6500. Wondering if maybe I should yank it back out and shim it maybe .020? Then again it's gonna drop when warmed up...

My God! I can't seem to make up my mind without consulting you guys first!rayer:

Run it? or de-shim it? OmR, you there?

 

[SRT_DSTRHOLC]

I get 75psi cold, i have to drive it slow until oil thins up because at 2k i can get near 100psi :/

 

[OldmanRick]

Yep Mike I just got here. 78lbs with a drill...Wow! Lucky you didn't burn that baby up turning it that hard.

Not sure if you posted what oil you're using, I'd have to go back and look? And your pan capacity? I know you went thru the lifters bleeding and I understand you're concern, but with that number you came up with "pre oiling" I personally would start with a oil viscosity on the low side of 5W max, along with a good oil filter to make sure it doesn't get anywhere near burst pressure.

I don't know what changing to a "20" shim will do? If you're up to trying it, my guess is it will put you somewhere between the 62 & 78 lbs. with the drill.

Other then putting it on the dyno as is and just seeing what happens, I really don't know what else to say right now? But "low" pressure shouldn't be any issue at this point.

 

[SRT_DSTRHOLC]

Also I am running a stock pump with deep pan and 6qts of 10w30