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Shim for 9/16 ball in oil pump.
What thickness shim do most guys run behind the spring when they drop to 9/16" check ball in oil pump ? .070 about right ?
Thanks for any replies. |
.065 hardened washer.
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I just tested my oil pump with 9/16 ball and .073" of shims behind 60lb spring. With 30WT and a 500RPM drill it went right to 67 lbs and settled in at 65 lbs.
Made a jig out of some 1" keystock. drilled a 7/16 hole that lined up with top hole on pump the other end went to a 1/8" NPT threads for the gauge. Then cross drilled it for another 1/8" NPT fitting. Put a 1/8" street elbow with 3" nipple dumping oil back down into the 5 gallon bucket. Did it with only 1qt of oil, worked fine. Used a 5/8" sleeve for a guide that lined up a oil pump shaft and the drill went on it. This was the pump I enlarged the pickup to .850 ID. I was a bit concerned it would be slow to pickup the oil but it picked it up very quickly. The middle of the pickup is a 2" long piece of sq tube so there was some extra volume to it. Worked great but I had to do it to make the 90 deg turn. I did not want to find out my oil pressure with the pan on and then have to take it apart if I did not like it. |
Nice. Care to share a pic of the pick up with the square tube?
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Is this a standard recommendation when installing a 60lb pump or is it only for certain circumstances? As part of my “quick fix” on my engine I’m replacing my current 80psi pump with a 60psi. Not sure if I should try the shim or leave it be. Mild (at best) street motor FWIW
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If you take some measurements. You should then be able to calculate what size shim is needed to get what pressure increase.
► seat_pressure = 60 psi ► new_spring_pressure = 67 psi ► spring_rate = 100 PSI per Inch ► (new_spring_pressure - seat_pressure) / spring_rate = 0.070" shim Stan |
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Why not put a high speed drill on the 80 pump and see what it's psi is? Melling rates the pumps for max, and depends on a number of factors. From the factory, the 80 pump is about 70psi, and the 60 pump about 50 psi. (Straight from a Melling engineer, and the article is available online to verify this claim, have posted the link numerous times) As for the ball, I know many do the ball swap, but personally, after 60+ engines, have never had a ball hang. If you disassemble a new pump and clean/check it, unless you have a lot of crap going thru your engine, the ball won't hang. And many have the same experience regarding as I have. But if you want to swap the ball and shim it, go right ahead, but it's not needed. For a performance engine, and/or an HR cam build, just run the 80 pump, and you won't have to do any mods. . |
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https://forums.maxperformanceinc.com...d.php?t=858334 In a nutshell, 4700 mile rebuild, low oil pressure at idle, concerns with what I found in oil and filter so I pulled it and found worn bearings and a very low pump pickup. Pump was an 80 which I thought was considered overkill so I got a 60 as a replacement. |
On my pump I made a jig and tested it, 67 lbs. That was with 30 WT Dello.
On the engine I primed it with Brad Penn 30 WT break in oil and I put about 2/3 qt of Lucas in it. Pressure was instant when I hit the drill and started out above 80 lbs and went up to 88 lbs. Must have been when the Lucas went through the pump before it all got mixed up. I was quite surprised with the increase in oil pressure. We will see where it settles in at. I bought a bunch of VR1 20-50 but this thing might end up as a 10-30 engine and no Lucas.. Got oil to the top of every rocker but one. It was the same deal when I primed my 455. Never did see oil on one or two rockers when priming with a drill. |
After examining my new Melling pump I went the route of honing the cylinder where the ball and spring reside to allow the ball to move a bit more smoothly and make it a bit less likely for garbage to get hung up.
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