I took apart my oil pump. Everything looks really good according to the factory shop manual specs, and so I plan to reassemble it with a new o-ring and reuse it. My only possible concern is there's a slight worn spot on the pressure relief valve spring. Any idea what caused that or if it's worth worrying about? I assume the pump is original to the 90,000 mile engine. I'm not sure, but I think the end with wear was the outer end, the cap end. Also, I haven't yet tested the spring force when compressed. Any tips on how to test that would be welcome too.

The wear is from the continual motion back and forth of the relief valve that it fits in. You can reuse it...based on the wear you shows at 90,000 miles, it might need replacement at 350,000 miles.

If you were satisfied with the oil pressure before, there is no real need to test the spring pressure. With a rebuilt engine, the oil pressure will presumably be the same or a little higher than before.

If you want higher pressure throw a washer or 2 under the spring.. or buy this one..

https://www.ebay.com/itm/292433320469

Yes its the same as a HEMI....

Otherwise reuse it.


Greg

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OK, so when people say "You gonna put a hemi in that thing?" I can say I already did.

Nah, I'm good with stock oil pressure. I just didn't know if that wear is normal or not. And it will take me a few years to get to 350,000 miles on this motor. Let's see, 12k in 5 years, so 260k more will take, oh, a century or so. By then the motor will be fusion powered.

Personally, I would reuse the stock one you have a put 0.060" thickness of washers inside the cap to raise the pressure 5-10 psi. I thought the hemi spring gave you over 70 psi? I did that once and had a rear main leak until I replaced it with a shimmed stock spring. No more leak and 60 psi max.

Lou

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I wonder if the Hemi spring gives a little less pressure than the Melling Blue spring? Any experience with the Hemi spring?

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I'm a big fan of non-high volume and non-high pressure oil systems.

For a low RPM Slant...especially given all the concern over oil pump drive gears....I'd really be in no hurry to see more than 50PSI, ever. If it's true that the oil pump gears are 'iffy', the more load you keep off them, the better....and pressure equals load.

Yep, 50 psi is more than enough for a stock or stock-ish Slant. I only run 60 in motors that see 6000 RPM and sometimes a bit over.

Lou

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