E-85 555 buildup- drag race by Jim Weise

3 minute(s) of a 87 minute read

Oiling system

As many of you know, this block has what is known as priority oiling for the mains.. simply put, it has another main galley, that feeds only the main bearings, and thru them the rods..

It's the reason for the third hole in the front and rear of the block, right around the cam tunnel.

These two pictures, of the front and rear of the block, will help clarify how it's different, and how it all works..

The priority main galley oils the mains first. 

The feed hole to the block, from the timing cover output is not drilled thru, so if you want to feed oil pressure in thru the hole in the passenger side (traditional sender hole) or at the rear of the block, you won't have to worry about plugging anything- this engine used an external feed line from the pan to the TA scavenger pump plate, pumped it thru a external filter mount, and then back into the motor, thru the traditional sender hole in the passenger side (which is 1/2 NPT tapped)

At the rear of the block, we see this..

Here is how it works..

Oil is fed down the priority main galley.. to the mains, and then out the back, up to the crossover tree, on the back of the block.

An oil pressure feed hole is right there (labeled oil feed in the pic) I used this hole for the oil pressure sender feed, in a dry sump or belt driven external wet sump pump, you could feed oil in here.

The oil is fed to the traditional lifter galleys, by the "tree" and they have to go past the oil restrictors.. this limits the amount of oil up to the top of the engine.

This is the oil restrictor..

The "restrictor is actually a Holley carb jet.. in this case, a 70 jet size is installed.

And as they are installed in the block..

Now, the threaded hole in the center of the block, between the two restrictors, intersects with what I labeled as "plug for lifter valley drain hole" in the first pic of the rear of the block.

This threaded hole is used for evacuation of oil and vapor out of the top of the block, when using a dry sump, or a vacuum pump.

What all this extra stuff does is simple..

1. the mains get oiled with full pump pressure, instead of having it bled off by the lifter bores.

2. the oil to the lifter galleys is restricted, thru an external pair of plugs, to limit the oil to the top of the engine.

3. Provides an extra oil pressure input, as well as a suction output.

JW