[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.