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Old 10-22-2022, 07:37 PM
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grivera grivera is offline
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From Butler Performance: https://www.pontiacv8.com/articles/2018/3/26/oilpump

Butler says that since an engine with smaller-diameter main journals (3-inch) and shorter-stroke crankshafts (4.21-inch or less) is generally less stressful on the bearings, a 60-psi pump may provide adequate lubrication in a modified engine, but an 80-psi pump is a better choice. He says any performance engine with 3.25-inch-diameter main journals and/or a stroker length greater than 4.21 inches should use an 80-psi pump. “The greater oil pressure associated with the 80-psi pump improves the strength of the oil film, and better protects the bearings in large journal and/or long-stroke applications,” he adds.

Common hobbyist concerns when using an 80-psi oil pump in a street engine include excessive parasitic loss, bearing wash, and premature distributor and/or cam gear wear.

“We’ve never seen a noticeable performance loss from the added load,” says Butler. “Racers will sometimes run a 60-psi pump to reduce parasitic drag and free up a few horsepower. While that’s acceptable in a dedicated race engine that’s frequently torn down, it’s certainly not something we recommend for all engines.”

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'69 Firebird 400/461, 290+ E D-Ports, HR 230/236, 4l80E, 8.5 Rear, 3.55 gears
‘66 Lemans, 455, KRE D-Ports, TH350, 12 bolt 3.90 gears
'64 LeMans 400/461, #16 Heads, HR 230/236, TKO600, 9inch Rear, 3.89 gears (Traded)
'69 LeMans Vert, 350, #47 heads: Non-running project