oil pump recommendations
Thread Starter
Intermediate
Joined: May 2025
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From: Galloway,OH
oil pump recommendations
Have a 68 L89 427/435. Seem to have a oil pump issue that is causing pressure to build to the point of blowing the seal on the oil filter. I think it possible is the pump. Any recommendations on a replacement oil pump for this model? Thanks in advance
Drifting
Joined: Jun 2025
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Unless Your motor is assembled with 'special' race-condition bearing clearances, Do NOT select a pump with Higher Volume or Higher Pressure than OE.
Stuff happens: Whatever pump you select, prior to install, DO disassemble pump and thoroughly wash out w/ mineral spirits/ kero etc, blow out all bits n pieces w/comp air, Inspect for any machined surface damages. Assure by-pass piston moves freely. Reassemble w/ conventional motor oil. Always select a brand new pickup tube with new screen. Once tube is properly positioned, tack weld it to pump body.
Stuff happens: Whatever pump you select, prior to install, DO disassemble pump and thoroughly wash out w/ mineral spirits/ kero etc, blow out all bits n pieces w/comp air, Inspect for any machined surface damages. Assure by-pass piston moves freely. Reassemble w/ conventional motor oil. Always select a brand new pickup tube with new screen. Once tube is properly positioned, tack weld it to pump body.
Thread Starter
Intermediate
Joined: May 2025
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From: Galloway,OH
not sure on the race condition bearing. This is a L89 car with the 427/435. If it is "special" will I hurt it going with a standard volume/pressure pump? I just don't want to blow 5 qts of oil all over the garage again.
Drifting
Joined: Jun 2025
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Treat the new pump as previously described.
Also, Do ensure you have a properly configured and working PCV system. Plenty of valid basic schematics on line.
Melting Slicks
Joined: Dec 2009
Posts: 3,229
Likes: 656
From: Thunder Bay
Get a good quality replacement pump in standard volume, standard pressure.
I had the same problem with the first engine I ever built. I had the bright idea to shim the bypass spring in the pump to increse the pressure. It worked. First time I revved the engine with cold oil it blew the oil filter wide open and sprayed the entire contents of the engine all over the driveway.
You know what they say: "Good judgement comes from experience. Experience comes from bad judgement."
I had the same problem with the first engine I ever built. I had the bright idea to shim the bypass spring in the pump to increse the pressure. It worked. First time I revved the engine with cold oil it blew the oil filter wide open and sprayed the entire contents of the engine all over the driveway.
You know what they say: "Good judgement comes from experience. Experience comes from bad judgement."
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Drifting
Joined: Jun 2025
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do ya KNOW how motor/pressure was acting Before it was parked some fifty years ago ?
several common reasons why an oil pump's bypass may be stuck --- gummed up is but one.
If ya truly think it's only gum --- offer some prayers --- drain oil, refill w/ a gallon of ATF + a quart of toluene.
OR
pull pan & oil pump, disassemble, soak, clean & inspected.
a New pump & pickup screen not even seventy $ --- even a new pump should be disassembled, washed out, blown out & inspected
several common reasons why an oil pump's bypass may be stuck --- gummed up is but one.
If ya truly think it's only gum --- offer some prayers --- drain oil, refill w/ a gallon of ATF + a quart of toluene.
OR
pull pan & oil pump, disassemble, soak, clean & inspected.
a New pump & pickup screen not even seventy $ --- even a new pump should be disassembled, washed out, blown out & inspected
Thread Starter
Intermediate
Joined: May 2025
Posts: 36
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From: Galloway,OH
Not sure on if this was an issue previously. We were told that when he couldn't drive to the airport to get fuel anymore, he parked it and covered it. Going ahead and R&R the oil pump, pickup and rear main gasket. I will clean the new pump and verify the bypass is free. Thanks for your insight. I'll let ya know how it goes. Thanks again
Melting Slicks
Joined: Dec 2009
Posts: 3,229
Likes: 656
From: Thunder Bay
That's good advice. Not much that can go wrong with an oil pump, and frankly I have a lot more faith in one that was built in the '60s than something manufactured (probably in China) today.
Thread Starter
Intermediate
Joined: May 2025
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From: Galloway,OH
I would rather change it if I am in there. Replacing with a Melling High Volume/Standard pressure M-77HV. Made and tested in Michigan. The rear main gasket is a Fel-Pro as well as the pan gasket. [size=21px]I appreciate your input. Thank you.[/size]
Drifting
Joined: Jun 2025
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Please reconsider a Melling M-77 (std/std)
While pan's off, highly suggest pull main caps 1, 3 & 5 and inspect Both inserts and journals.
Likewise for rod caps 1, 4 & 8.
You'll need to feed this motor w/ oil rich in both Zinc and Phosphorus. Things have changed in Fifty years: Most of today's shelf oils do Not contain sufficient Zn or P for your flat tappet cam.
Thread Starter
Intermediate
Joined: May 2025
Posts: 36
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From: Galloway,OH
After some extra research, I think i will take your recommendation and go with the M-77. The goal is to have the car run and idle for a potential buyer to see. If I was buying this car, I would go completely through it mechanically. From engine, transmission, brakes system, fuel system, electrical and vacuum systems. The goal for us is to show an original, numbers matching example that runs and idles. I appreciate your insight and recommendations. Thanks again