High Pressure Oil Pump

Can someone be so kind as to tell me what are the pros/cons and where/when to use them?

I am mostly thinking for 4cyl NA "race cars"...I also wonder about the likely hood of having "extra" oil leaks due to the higher pressure, and also worried about over pumping up the hydraulic lifters.

tia....

The higher oil pressure shouldn't effect leaks, since the higher pressure is mainly on the internal points (bearings/lifters). It will make a difference on the oil filter and cooler lines (if fitted), but it shouldn't be anything they couldn't handle.

I've never seen an issue with too much pressure on lifters, but that is a valid question that I can't answer with certainty.

More isn't always better. Too much pressure means you're wasting HP. Billzilla (look him up) had a friend in a spec class that dropped his oil pressure, picked up HP and was faster than the other cars with otherwise identical spec'ed engines.

Dr. Hess wrote: Too much pressure means you're wasting HP.

Good point, I didn't think of that.

Also, a high volume pump can out pump gravity, leaving you with a head full of oil and a dry crankcase.

Hi pressure oil pumps are/were popular with engine builders that use large clearences in their engines. The thinking is that a "loose" engine will spin faster and easier. Works OK for a drag motor but for a street or road race engine not so much. The horsepower the loose motor frees up can be eaten up by the load the Hi pressure oil pump puts on the engine at lower engine speeds which street and road race engines see more of then a drag race engine.

There are some engines that need this hi pressure. Some old English 4 cyl. engines with 3 main bearins instead of 5 run hi pressure when used in racing.

Appleseed, you're confusing two different items.

High Volume pumps may or may not work at higher pressures, but they typically pump more oil per revolution.

High Pressure pumps provide higher oil pressures but may or may not provide more oil volume per revolution.

Basically, unless the engine has a habit of running low on oil volume or oil pressure then you might need to change the pumps or the pressure relief spring out to try and resolve that issue.

However 9 times out of 10 the issue isn't so much with the pump as it is with the pickup. The pickups can get uncovered under hard cornering and then you lunch a motor.

I've seen on my Chrysler 2.2/2.5 turbo motors where the #4 rod bearing take a beating compared to the rest, the condition looks to be due to oil starvation. After much kanoodling, we've surmised that it is the over-sized oil feed lines for the turbo chargers that must be contributing to the issue. Looking at the specs from the Chrysler engineers and Garrett, we find that the feed line only needs to be 1/8", not 1/4" but the smaller lines could break off in a crash and cause a fire. A restrictor in the oil feed fitting helps resolve the issue.