Oil pressure balance line

I was thinking of adding one to my 350 before it goes back in the car, but decided against it for two reasons, I don’t like the extra plumbing and potential for leaks ( it WILL leak) plus I still question the benefits from it even tho I read and reread JWs write up on it.
In the write up JW said with both lines hooked up the overall system pressure dropped to the rear reading which happens anyway with the standard oiling set up which makes sense due to 5 main bearings, 8 rod bearings, 5 cam bearings and 16 lifters peeing oil.
I would think if the balance line had any benefit it would bring the pressure up to the FRONT reading
My theory ( probably doesn’t hold water, lol) is unless the oil trying to enter the rear of the oil galley is higher than the front the pressure from the front is allowed push the oil at the rear entry backwards and drop system pressure, similar to a wheel cylinder, if you push on one side the piston will push out the “pushrod” on the other side unless equal or greater force is applied to the opposite side.
Ok, there’s my meandering thought for today.
Any fluid dynamics pros on here to straighten me out??

 

Mark,

That line was always about insuring adequate volume to the rear of the engine, especially race motors with looser clearances and a need to flow more oil across the bearings to keep them alive. Volume and pressure go hand in hand.. and when you bypass all the calibrated leaks, and feed the system behind those leaks, and the observed system pressure drops, then that indicates that the engine wants to flow more oil than it can, with a single pressure entrance. To some extent, this will be true for all engines. It's why the engineers reduced the size of the passenger side main galley that feeds the mains, about halfway thru the engine. This was an attempt to provide more oil pressure to the rear of the engine.

It's important for engines with non priority main oiling systems, with large main and rod bearings clearances, operating at high rpm. While it can be added to any engine, the benefits on a street engine with proper clearances are considerably less. I built about a dozen street engines with them as a design study in the late '00 early 20 teens.. mostly on engine above 550 HP. Then I built a dozen more without the line, in the following years.

All those engines are still in service to my knowledge, so there obviously is not a big difference, what subtle differences there might be, is unknown to me at this point.

I still employ the line in iron race motors, with big clearances, designed to run north of 6000 rpm, but have discontinued installing it on street engines below 600 HP.

JW

 

I had my machinist add the line on my block but having an issue with getting a fitting to clear the plate for the scatter shield. Ordered a steel 1/4” x 1/8” 90° he used a braided -3 line to the front of the block. If that doesn’t work the 1/4” pipe plug will.

 

That makes sense to me now, thank you for the detailed explanation!
So this mod is more beneficial to race engines with larger than say .002 bearing clearances?

 

Flexplate or flywheel going to clear those fittings? Only abt 1" from blk to plate.

 

Unless the picture is reversed your oil line is on the wrong side

 

Careful with driver/passenger side advice, Larry...luckily the Netherlanders sit on the left and drive on the right as we do in USA!

I'm doing tech writing for GM nowadays, and the driver/passenger jargon globally still gets some folks into trouble which I undo from time to time.

And I concur Job, you've connected to the wrong side at the back of the block. Should be fitted to the the right side, sorry for extra work (on your side).

So, here's to Right, Left, Front, Back as we sit behind the wheel going Forward!

Devon

 

Oeps...so this is not the way to go. For 10 years it is still no problem but will you explaine why it shut by on de passengers side??

I use flexplate.

 

This is news to me, Job! I thought Dutch folks drove their cars on the right side of the road/street/lane.

Has this changed?

Devon

 

Sorry, we drive on the right en steering on the left. Same as in the US.
It's also very difficult. LOL
But my oiling is on the wrong side...

 

Thanks for clarification. And sorry, yes you should connect the oil line to the right side. I hope the engine is still out, this makes things much more easy.

Devon