Re: Oil Pan question
The ultimate solution obviously is a dry sump system in which the oil is stored in a remote reservoir. The only oil in the pan is what drains down before it is scavenged/sucked up by the dry sump pump and retruned to the remote reservoir. Additionally, you run a higher amount of crankcase vaccuum, allowing you to run low tension piston rings, further freeing up horspower from the reduced piston ring/cylinder wall friction. Also, since you don't ahve the oil pump in the pan, you can run a full length windage tray. Alot of the 4 and 5 stage dry sump systems scavenge oil from the top, from the lifter valley and/or the valve cover areas. This way the oil doesn't even have a chance to fall back onto the rotating assembly and get wrapped around.
For a wet sump applicaiton, there are also alot of tricks you can do to free up as much horsepower as possible. I run a custom made Stef's aluminum sheet metal oil pan. The one I use is intended for Competion Eliminator - tube chassised doorslammer altered, or other dragster limited to a wet sump system. It's a trick pan, but it does have it's inconveniences. One of the biggest ways to free up power, and reduce windage is to use a kickout design pan. What this means is that one of the pan, the left side if your looking at the front of the engine, is kicked out past the side of the block. This is the side of the pan that the rotating assembly slings the oil into. Since it's kicked out, and there's basically a roof over it, the oil cannot continue to rotate or wrap around the rotating assembly, and simply runs back down the side of the pan into the sump. The downside of this is the the left side pan bolts studs are inside the pan. To access them, you have to first remove o-ringed screw-in plugs in the bottom of the pan.
Additionally, the pan features a teflon coated, uni-directional windage screen, several uni-directional trap doors and baffles, and a rear ledge to prevent oil from climbing up the back of the engine under hard acceleration.
Also, with a 9" deep sump, the oil is kept as far away from the crank as possible.
Anotehr upgrade you can do with a wet sump is to run an external wet sump pump. This is basically a single stage dry sump style pump, with one suction and one pressure stasge. You install a bung, usually a -12 or -16, in your pan with a pickup, and run an external line from the pan to the pump, then from the pump back into the block, through the front or rear oil galley pugs located at the top of each end of the block. One of the benefits of this is that now you can run a full length windage screen since you don't have the pump inside the pan. This will free up some horspower. Also, since you're not driving your oil pump via the cam, there's less cam/distributor gear wear and you could pickup a few addtional hp due to reduced spark scatter and cam/distibutor harmonics created by the oil pump.
Here's a picture showing the o-ring plugs I have to access to get to the pan studs.
Here's a couple of pictures illustrating the kickout to one side.
Here's the inside of the pan, with the teflon windage screen, trap doors and rear ledge.
Here we are fitting the front end on:
Just Kidding, I wish!
Anyway, here's how it looked after I intially installed it, this is from last May:





This is my vettes 8 quart road racing pan. It has the kick out, baffles, and a PITA adjustable crank stripper. It probably took ten on and off fittings to make sure that it never touched the crank with crank end play. It's a special pan for 4 inch stroker cranks.

[Modified by gkull, 10:16 AM 11/2/2001]













