[rsrogers]

I purchased a 426 hemi that the engine builder put Pete Jackson timing gears in. To lub the gears he drilled an 1/8 hole in the oil passage right behind the gears to "spray" on them. To compensate for the pressure drop he installed a high volume oil pump. The pressure dropped 10-12 psi at idle but "ran" 90 cold and 45-50 hot. I did not like this so I installed a .060 carb. jet to reduce the hole dia. but it didn't do as much as I liked. It only gave me about 5 psi better. Question: should the gears get enough oil the traditional way that the "old" chain would have gotten oiled. I want to plug the hole and use all my pressure. Note: car was built in Miss. There is no "bringing it back for him to fix".

[willys36@aol.com]

I answered this question on your thread in the Introduction forum but it disappeared!

Anyway, 90psig is WAY too much pressure for all but the most powerful race-only engines. 45psig is plenty at speed and 12psig is at the top of the range for idle. All the pump does is supply oil to the bearings in sufficient quantity and 40psig will do that. Pressure that the pump generates has zero to do with actual lubrication in the bearing itself. In fact your very high pressure will wear out your oil pump drive gear very quickly. If anything, you have a problem with too much pressure.

[swvalcon]

Rule of thumb is 10 psi for ever 1000 rpm. So 10-15 psi for idle is fine . As willy said to much oil pressure can kill a street engine. 45- 55 is all you should need. Takes hp to turn that pump at 75 psi.and up