Running Pete Jackson cam gear drive in a 426 Hemi

1964moparnut · Post by **1964moparnut** » Wed Mar 02, 2005 5:01 am

I bought a 426 Hemi w/Pete jackson gear drive. The engine was already installed in a car purchase-I did not have it built for myself. The engine builder drilled a .12 hole in the oil passage under the timing chain cover to squirt oil on the gears and installed a high volumn/high pressure oil pump to compensate for the pressure drop. This "leak path" has got my pressure all over the map. When cold my pressure is about 80 psi, hot it is about 12 psi. I drilled and tapped the hole and installed a .060 carb. jet to reduce the hole dia. and retain more of the pressure "inside the motor." That didn't seem to do much. I then installed an oil cooler and that seemed to help more. My question: Is the "leak path" hole required? Could I possible plug it with a set screw and feel confident that I am not causing damage? Is there something I am overlooking that is a fix but not such a gamble. Please Advise. Thanks

hemi4711 · Post by **hemi4711** » Wed Mar 02, 2005 10:41 am

If it was my engine I would plug the hole. The timing chain is oiled through splash. I think the gear drive is the same, No extra oil is needed.

mart · Post by **mart** » Sat Apr 02, 2005 1:45 pm

I agree that the gear drive should not require the additional oil hole to lube and it could be- should be plugged. However, with the hole now reduced with a .060 carb jet, I doubt that this is causing enough of a leak to reduce your oil pressure. I'd look elewhere. Maybe problems with bearing clearences - mains, rod or possinly cam beraring or a problem with the crank or cam or the valve gear, or within the oil pump.