[Steve C.]

A fwiw, Canton recommended pickup to pan clearances of 5/16-3/8 inch. And mention the gaskets will add some additional clearance.

.

[Tom Vaught]

Originally Posted by lust4speed

Getting back to the original question which was how far off the bottom of the pan could the oil pump pickup be placed. The problem might be looked at like computing the area of an air filter, and using this to figure out the capacity under the pickup when 1/4" off the floor. Thinking of this area like the circumference of a cylinder that is the diameter of the pickup and the height being the distance off the floor. We can use Tom's 3.6" screen diameter and this produces a circumference of about 11". Take the 1/4" height from floor to pickup and that gives 2.75 square inches of effective area the oil has available to pass through. This is only about half the capacity of the screen area but many times over the flow rate of the pickup tube area which will be the choke point.

So thinking 1/4" would be totally safe? Distance could be less according to the math, but no reason to push the clearance any tighter.

I am thinking years ago, that I did the same calculation and that was why I used the 1/2 height because the area around the screen matched the screen area. We also know that a higher pressure suction on a device, be it a carb or head tested at 20.4" of water vs tested at 28" of water) increases the flow reading thru the tested device. Now if you have a large inlet, be it a carb or a Aston Martin inlet pump from Luhn Performance you know that pump is not going to be pulling very hard to get a given flow.

Tom V.

[mrennie]

Perhaps I am missing the obvious, but something that is fuzzy to me...

...what negative effects are there if the pickup is higher off the pan floor than ideal?

I understand that the pickup cannot be too close to the pan, or else it hinders suction and could affect flow.

But what bad happens if the pickup is say, 1" off the floor? The only thing obvious to me is that you loose some oil capacity in the system, as the oil that cannot get sucked into the pump effectively disappears as it cannot be used...but is that it?

Thanks

[Tom Vaught]

Originally Posted by mrennie

Perhaps I am missing the obvious, but something that is fuzzy to me...

...what negative effects are there if the pickup is higher off the pan floor than ideal?

I understand that the pickup cannot be too close to the pan, or else it hinders suction and could affect flow.

But what bad happens if the pickup is say, 1" off the floor? The only thing obvious to me is that you loose some oil capacity in the system, as the oil that cannot get sucked into the pump effectively disappears as it cannot be used...but is that it?

Thanks

If the pick-up is mounted higher, as in your example, for a normal street vehicle you would never notice the difference in the extra oil below the pick-up screen.

If you are a drag racer or road racer and the pick-up is 1/2" higher vs the upper height distance, then when you accelerate (or turn corners sharply), the pick-up being slightly higher has more chance of seeing air vs oil and you would then be adding air and oil mix to your engine.

Road Race pans have trap doors to keep the oil from running away from the pump pick-up. This means the average oil level in the pan around the pick-up is higher and less chance of air entering the engine.

Some put a deflector baffle on the back wall of the oil pan (about 3 inches up) to force the oil climbing the rear wall under acceleration to turn quickly back into the sump and keep the pick-up covered.

So if you drive smoothly it makes no difference, if you drive like a NASCAR guy or a Drag Strip guy you need mods besides the stock oil pan. making sure the pick-up is about 3/8" is in the ball park for a good location but does not fix a racing oil starvation issue. Same deal for slamming on the brakes and having the oil run to the front of the pan on hard decels after the pass.

Tom V.

[lust4speed]

Another way to look at it is that 3/4" of oil (increase from 1/4" clearance to 1") the engine no longer has access to is about 8/10 of a quart. So in reality it should be the same as running the engine about a quart low on oil.

I'll add one more to Tom's list of when it might matter -- Early Edelbrock heads were notorious for holding oil up in the valve cover area, and the missing oil might be the difference between an engine that lives and one that fries the bearings - and no drag racing needed, just buzzing along at a good clip down the freeway.

[Tom Vaught]

Originally Posted by lust4speed

Another way to look at it is that 3/4" of oil (increase from 1/4" clearance to 1") the engine no longer has access to is about 8/10 of a quart. So in reality it should be the same as running the engine about a quart low on oil.

I'll add one more to Tom's list of when it might matter -- Early Edelbrock heads were notorious for holding oil up in the valve cover area, and the missing oil might be the difference between an engine that lives and one that fries the bearings - and no drag racing needed, just buzzing along at a good clip down the freeway.

Very True! I (and my son) check the oil level on his truck (160,000 miles on the engine, runs well) every time he starts on a several hour trip in the vehicle. If the oil is 1/2 a quart low we top it off to the full number on the stick vs potentially hurting the engine on some of the hills that he encounters on the trip. Oil is cheap vs road service. They get their money one way or another.

Tom V.

[Tom Vaught]

No long weld bead. Just small tack welds in several places.
And the pick-up is supported by the tube inserted in the casting.
It has worked well in that location for years and millions of miles on a fleet
of Pontiac vehicles over the years. The 22 gage strap is fine.
If you use a vice grip you can get the reinforcement piece around the tube
a bit tighter but the pickup should not loosen with just a few tack welds on the support piece and the tube. Find where the tube rests closest to the strap and tack weld it at those locations for less stress on the welds.

Tom V.

[b-man]

I usually grind the pump cover plate so I can adjust the pickup to where I think it belongs, about 3/8” to 1/2” from the bottom of the pan at the lowest point of the pickup. It ends up sitting at an angle of course but not too severe.

Putting the pickup in the notch seems too high in my opinion.

I use either a ball of foil or modeling clay to determine the clearance. Never had any issues doing it that way.

My experience is with 13-second daily driver street engines and low 12-second bracket race engines usually not spinning much more than 5500 rpm using the 60 psi Melling pumps. Never welded the pickup in place or used any support strap.

I drilled and tapped the pickup tube and pump body where they mate to secure the pickup, 10-32 socket head cap screw installed using red Loctite. My latest engine (mostly stock/restored 421 HO) was built by a friend who prefers to tack weld the pickup, he has built numerous engines for himself and other friends with no issues so I had no problem with his method of securing the pickup.

[Richie Hoffman]

i trim pump cover so i can get pickup height we’re i want it putting screen in notch makes screen a little to high

[SusieQ]

Originally Posted by b-man

I usually grind the pump cover plate so I can adjust the pickup to where I think it belongs, about 3/8” to 1/2” from the bottom of the pan at the lowest point of the pickup. It ends up sitting at an angle of course but not too severe.

Putting the pickup in the notch seems too high in my opinion.

I use either a ball of foil or modeling clay to determine the clearance. Never had any issues doing it that way.

My experience is with 13-second daily driver street engines and low 12-second bracket race engines usually not spinning much more than 5500 rpm using the 60 psi Melling pumps. Never welded the pickup in place or used any support strap.

I drilled and tapped the pickup tube and pump body where they mate to secure the pickup, 10-32 socket head cap screw installed using red Loctite. My latest engine (mostly stock/restored 421 HO) was built by a friend who prefers to tack weld the pickup, he has built numerous engines for himself and other friends with no issues so I had no problem with his method of securing the pickup.

Originally Posted by Richie Hoffman

i trim pump cover so i can get pickup height we’re i want it putting screen in notch makes screen a little to high

Upon further inspection, I came to realize that the cover plate lip at the notch overhung quite a bit, so I came to the same conclusion. But I still wanted to hear the opinion of the pros before doing any grinding so thanks for the input.

b-man, I fabricated a bracket to hold it in place. Scroll down a bit and you'll see pics. I'll be drilling holes in it yet to weld to.

Thanks again guys!

[Tom Vaught]

Looking at SusieQ's, oil pump picture, I have a question:

a) We already agree that the pump screen should not fit into the notch but the screen "lip" should be a bit lower on the pump and flatter on the bottom of the oil pan.

b) Most agree that a strap is not a bad idea to retain the pick-up to the pump.

So here is my question/ proposal.

If you mounted a flat strap on the bottom of the pump, (but not to the bolts closest to the pump inlet but the ones closest to the "notch" on the pump, and then located the screen so that it was more "flat" when installed in the pan (by welding the strap above the lip on the top of the pick up screen) then three things would happen.

a) The screen would be flat with the oil pan bottom surface.
b) The bolts/strap would securely keep the screen from vibrating (because you are not using the notch (which was cast in the pump housing for that purpose in the oil pump design).
c) The screen once installed could not come out of the pump because it could not move due to the oil pump cover "retention" fasteners and fabricated strap.

Tom V.

You could call it the Susie Q "Oil Screen Mod".

[SusieQ]

Originally Posted by Tom Vaught

Looking at SusieQ's, oil pump picture, I have a question:

a) We already agree that the pump screen should not fit into the notch but the screen "lip" should be a bit lower on the pump and flatter on the bottom of the oil pan.

b) Most agree that a strap is not a bad idea to retain the pick-up to the pump.

So here is my question/ proposal.

If you mounted a flat strap on the bottom of the pump, (but not to the bolts closest to the pump inlet but the ones closest to the "notch" on the pump, and then located the screen so that it was more "flat" when installed in the pan (by welding the strap above the lip on the top of the pick up screen) then three things would happen.

a) The screen would be flat with the oil pan bottom surface.
b) The bolts/strap would securely keep the screen from vibrating (because you are not using the notch (which was cast in the pump housing for that purpose in the oil pump design).
c) The screen once installed could not come out of the pump because it could not move due to the oil pump cover "retention" fasteners and fabricated strap.

Tom V.

You could call it the Susie Q "Oil Screen Mod".

I think it's an interesting idea Tom, but I'm already going to weld the existing strap directly to the tube, so wouldn't an additional strap be redundant? And if I welded that secondary strap to the screen, wouldn't there be a risk of damaging the thin screen material?

I'll grind down the lip that prevents the screen from rotating downward to my desired position. Then I'll be drilling two holes in the strap at the tube and welding in those locations, as well as drilling a hole in the part of the strap that wraps around the tube, tightening it with Vice-Grips, and welding that. I can't see how it could ever move.

[Tom Vaught]

Not saying in your case that you cannot do it exactly the way you described and with the bracket you currently have. Go for it.

That being said, at Ford we had welders who could weld a bead on .015" feeler gage strip steel with a TIG and not blow thru the strip. So the oil pump screen housing thickness would not be an issue for some. Do not change what you are planning on doing.
I was suggesting the relocation of the strap for others who might want to do something similar to what you did.

Tom V.

[brdngtn]

After reading all the above, and since I have the original 1968 242 block, pan and pump, I decided to investigate how it came from the factory. With original pump bolted in and block upside down, I measured the tallest point of the tilted screen 7 1/8" from oil pan mounting surface on the block. When I went to measure the pan depth, I wondered where to take my measurement, so I put a roll of tape on the pump intake screen and placed the pan (with drain plug in it). I discovered that the pan cannot be placed directly inline with mounting bolt holes, it needs to be be moved forward and then rear again for the screen to clear the drain plug. No one would normally notice this because the drain plug is removed before the oil pan. Due to the curved inlet pipe, the screen can pivot to avoid the drain plug once installed, but cannot be forward enough to miss it entirely. This tells me that, from the factory, the intake screen is installed so the drain plug end comes in above it, and that the screen itself tilts down into the well leading to the drain plug.

My new Melling M-54D-S came with intake screen tube 1/2" shorter which moves it off center toward passenger side but same front to back. It can ever interfere with the drain plug, but will miss the drain plug well so will need to be shallower than the original just to not hit the bottom of the pan.