a friend has an engine that, by its very design, has poor oil pressure in the lower rpms, i suspect its due to a tradeoff in the oil pump design so as not to “waste” hp in the upper rpms (7500+)
would it be possible to use an electric tilton oil pump, which pumps 1 gpm @ 60psi, to create a secondary oil pump ?
i was thinking that by installing a second pickup, then plumbing that to a tilton pump on the frame, and then to one of the gallery plugs in the block he would be able to up his oil pressure in the lower rpm range
by installing a simple bypass in the line between the pump and the block, he could dump any extra oil back into the oil pan, so as not to overload the pump, and so oil pressure in the block doesnt climb to high
this would also serve the purpose of making sure the turbo’s dont drain to much oil pressure away from the engine when pressure would be already critical, and could also serve as a priming pump for the engine b4 its started
i wouldnt bother chances are it will send pressure back to main pump and just bypass the pressure regulator there as far as startup yeah its not a bad idea but just think of how many cars out there start every day without primimg
i have issues wiyth my motor not having much oil pressure at low rpms but after the 4 th year now still no problem id say run it
well the oil shouldnt escape thru the main pump, becuase its positive displacement, and the stock bypass valve wont bypass till its releif pressure is reached, so i think he’s safe there …
he just wants to add 2 small turbos to get better low end, and they will prolly spool by 2500, which is in the “danger zone” as far as oil pressure goes
You could remove the pump and change the pressure releif spring with a slightly higher one. However this is dangerous as oil pressure in the higher rpm may be a tad too high. It depends if the oil pressure issue stems from a weak spring
I dont think 1 GPM is going to make much difference for you, which actually may be positive too, as you only want to add pressure to the lower RPM range. as the flow/RPM increases, that steady 1 GPM will become less and less of the overall flow.
For example, a gerotor type 1" dry-sump pressure pump flows about 3 GPM/1KRPM, and a 1.5" pressure section flows about 5 GPM/1KRPM.
As you can see, these small gerotor pumps could be flowing 20+ GPM at 7K depending on drive ratio… adding 1 GPM wont do much, but it might net you a couple PSI down low. I would recomend hooking it up to a temp switch, so it only comes on when the engine is running, and above a certain temp range. clearances will be tighter and oil thicker when cold, you dont want to add undue stress to OEM pump or new pump until the pressure starts to drop off anyway during warmup.
How much pressure are we talking about here anyway at idle?
If this is a dsm remove balance shafts and problem solved. If not hook up the pump to turn off at a desired rpm when the stock pump has sufficient pressure. Maybe use an autometer pill box for a shift light for the rpm trigger.