Oil tube block mod

Anyone know why this was done. I don't understand this.

They probably wanted to prevent oil pressure loss if a right bank lifter popped out of the lifter bores, I would have used a much smaller line (1/8 to maybe 1/4 inch O.D.) to oil the driver side lifter oil galley to reduce the oil pressure loss if one of them came out
I've had blocks bush in all 16 lifter bores to do the same thing as well as fix any of them that were too big on the I.D. or made crooked

Looks like they were minimizing the tube that was (is?) used in small block mods to bypass oil into the left galley in order to slow down the oil flow through the system and/or prioritize oiling to #1 main. Even though the big block system is plumbed differently. That was some 70s and 80s tech that I never got on board with. There are other, better ways to fix these.

If you're going to run a mechanical cam, the left galley should be made dry as it does nothing but oil the lifters. Bushing the lifter bores is almost a necessity for high RPMs and a good idea for everything else to control those 16 massive internal oil leaks.

Not sure why you would want to do that. Most of us block it off so no oil gets there. But we run flat tappet cam. no reason to have oil there. More oil goes down to the mails and rods.

Maybe they thought they needed to feed more oil to the lifters to keep the cam from going flat?

Only reason to oil the lifters from the galleys, as opposed to bushing the bores, is if you are using hydraulics or oiling the heads through the pushrods. Can still be bushed and drilled instead of having those huge oil leaks.

Not going to help unless you have EDM lifters. Still don't need those huge holes feeding that lifter.

Didn't say it would, just speculating on the thought process that went into that mod.

I think they did it to get oil down to the mains quicker, on a stock motor the oil goes down the pass side crosses over in the back then runs all the way to the front on the dr side when it dead ends then the oil can be forced down to the mains, by filling the dr side with that tube as soon as the motor is started you don't have to wait for the oil to run it's normal course before feeding the mains. makes sense?

The only thing fed from the left side on a BB is lifters. The theory is oil is rushing through the right side so quickly, as it has to feed the mains AND the left side from the end of the right galley, that the oil can't make the sharp turn to the main feed passages.

My theory is, plug or drastically reduce all the dang leaks so the oil isn't rushing through the system, squirting out all over the place, and can keep the crank full and under pressure.

High RPMs is where the issues show up.

The guy has this block and a stock steel crank for sale for 2100.00 !!

Seems high to me

Gus

The price or the seller? Or both?


This may or may not have been involved before that price was set. Just sayin'

Augments the crossover at the rear of the block.

I don’t see any benefit to stealing oil from the main feed from the pump, before it even gets into the main gallery.......and sending it to the pass side lifter gallery.

I’m not seeing it benefiting any of the bearings.

More oil to the drivers side lifters....... for whatever that might be worth.

Maybe in some race application that required running hyd lifters, where they felt the oil supply to the drivers side was compromised and caused lifter bleed down issues at high rpm.
Like NHRA Stock eliminator before the Schubeks came on the scene.
Nowadays you can just run solids.

The mod sends it to the drivers side gallery.

However, the only thing being lubed from that galley is the lifters. 8 large leaks spraying oil that could be better used on the crank.

Putting oil in at the end of the system there basically fills the galleries from both ends. Intended to stop the oil from flowing through and ensuring the entire system is consistently full and pressurized.

Again, solid lifters or not oiling the top end through the pushrods, or oiling the heads externally, plug the left galley and make it dry, eliminating the problem.

Using an internal auxiliary hose/tube can be beneficial, if the left galley is plugged and the oil is plumbed into the rear of the right galley, filling it equally from both ends.

Right...... typo on my part.

Oil is diverted into the drivers side gallery from the main feed out of the pump.

i would just plug it, looks like it would be a big oil pressure loss, he may have had cam issues?

Cam is oiled from the mains. 5 more big leaks.

Every pressure-lubricated component in the engine that has clearance is a "leak", not sure what constitutes a "big leak" compared to a normal leak from clearances within tolerances. Whether the leak is close to the pump or at the end of the system, it's still a leak that reduces the overall pressure.

I see a benefit to the subject mod as it feeds the system from both ends. The leaks and resultant loss of pressure won't change.

True. I will clarify by saying - reduce necessary internal leaks to a minimum and eliminate those which aren't needed. I define "leak" as anything oil is being fed to that is not a main bearing, and anything being fed oil from the main bearing bore. Obviously, everything needs to lubed. It's the priorities and what percentage of what is coming from the pump to each area that I address.

Lifters. A 9/16 oil passage wide open into 16 lifter bores. The only restriction to spraying out is the .0015-.002 clearance. Solid lifters need no oil from the galley. Pressurized lifters can be taken care of with a small hole in the bushing.

Heads/valvetrain. Can be kept happy with a restriction much smaller than the 1/4"-9/32" hole from the cam bearing(s) to the heads. And/or even better they can be fed from someplace other than the cam bores,

Cam bearings. Again. Plenty of oil from an .035-.045 hole. Especially if the heads aren't fed from the cam bore(s).

The amount of oil you can get out of an .035" hole with 60-80PSI behind it is surprising when you see it.

Putting oil into both ends of the right side galley will show some benefits. Takes a little plumbing.

The object of the exercise is to reduce or eliminate "leaks" from the main right side galley in order to keep as much oil on the crank as possible. Rather than filling up the valve covers or have it be caught up in the tornado occurring in the bottom end.

Typically, the benefits to all of this begin to show up when the RPMs get above 7k or so.

I've done this (and some other little things) on high RPM deals and the difference it made in the rod bearings was amazing. Stock crank, high RPM 360s I've had would not live without doing this.