Installing HV Melling oil pump

[ek02]

I found some info on pressure drop. According to Jim Ruggles in his old Buick Performance book, he saw a 9 PSI drop on an engine with tight clearances. Not as much as I would have guessed. He said his endurance engines survived all day on 60-65 PSI. That was with a stock pump with a booster plate and restricted cam bearings. In some old Kenne Bell literature I dug up, Jim Bell said the drop was 10-20 PSI depending on clearances. He once told me he never liked the Ruggles restricted cam bearing trick to restrict oil flow.

 

[earlbrown]

I'd listen to Ruggles before Kenne-Belle.

The reason there is a pressure drop isn't because of the bearing clearances. Pressure by definition is the same everywhere and exerts itself in all directions.

The only way you can have two different pressures is to overwhelm an orifice and have a pressure drop or overwhelm and orifice and have a leak.

In the case of the test you mentioned it's slightly #1 and mostly #2. There's a little pressure drop from (4) 90's between the pump and the passenger side lifter rail. The pump spring sees pump pressure. An oil pressure gauge mounted at the brass block will read pressure after going through 2 or 3 90's (not much drop there)

A gauge mounted at the back of the block will show a drop after all the lifters bleed off oil. There's no bearings there. The faster the oil goes, the less pressure drop there will be.

 

[Steve V]

I have used the restricted cam bearing method in a few of my personal builds. No problems and the car that has 30-35 at idle with 5w 30 has this mod. I have not done it on any customer engines, they all get TA cam bearings anyways.

 

[turbo nasty]

I have used the restricted cam bearing method in a few of my personal builds. No problems and the cat that has 30-35 at idle with 5w 30 has this mod. I have not done it on any customer engines, they all get TA cam bearings anyways.

Imo that oil psi with 5w30 is not the norm...but if it works for you then rock on.

 

[Steve V]

Imo that oil psi with 5w30 is not the norm...but if it works for you then rock on.

I agree. it was assembled with .001 bearings from the factory too. Figured if I used standards and good oil pump it would be right. It is a bit of a freak cause I have yet to get another that high.