Jan. - Feb. 1997 Motor State Performance Report Article By Jim Kaekel, Jr.
If you could actually take a "Visible V-8" kit, assemble it, fill it with oil and watch it run, you'd be able to see the negative effects of a wet sump style oiling system.
You'd see a high-revving crankshaft whipping oil up from the sump and turning it into an aerated froth. At 6,000 rpm, the inside of the crankcase would probably look something like Hurricane Hugo. Add to this situation the G-forces created by a properly dialed-in circle track car, or the forces in a drag car with lots of torque propelling it into a giant wheelstand and you'll realize the need for oil control in a race engine.
The above conditions use up precious amounts of horsepower; horsepower that is produced during the combustion process, but is quickly dissipated because of the rotational drag of oil hanging onto the rods and crank, particularly the counterweights.
The oil tends to sling all over, splashing into the sides of the pan and back onto the crank. when you have five or six quarts of oil located directly below the crank, it can be very difficult to control.
Switching to a dry sump system would be the ultimate solution, but may not be allowed due to class rules or budget restraints. There are several different devices designed to prevent oil from slowing down the crankshaft assembly. Companies such as Canton, Milodon and Moroso all offer various windage trays, screens, baffles and deep sump oil pans which can make a bad situation much more tolerable.
The most effective method of correcting oil windage problems is to increase the distance from the crank to the sump.
This is accomplished by simply installing a deeper oil pan. Improved wet sump technology has resulted in deep sump oil pans that are available with built-in windage trays, pouches, and crankshaft scrapers.
Moroso's best selling street/strip small block chevy oil pan, Part #20190, even features a one way trap door in the sump to help isolate the oil.
Moroso's Part #21010 for small block Chevy not only features a built-in crank scraper , but also a teflon-coated windage tray to aid in quick oil return to the sump. Crankshaft scrapers are valuable aids, helping remove oil from the lower rotating assembly. Scrapers are designed to be placed on the pan rail between the engine block and the oil pan.
Moroso also offers scrapers individually, Part #25800 for small block Chevy, and #25830 for big block Chevy, that are fabricated from .035" steel and must be lightly trimmed to gain .045" desired clearance from the crankshaft and connecting rods. Canton also makes a selection of scrapers available , including versions for big and small block Fords.
Many top of the line wet sump pans feature aluminum construction, a built-in screen-type windage tray and crankshaft scrapers. Moroso's Stage II "Pro Eliminator," Part #21227 for early small block equipped '67-69 Camaros, is a good example. Many top engine builders feel that screen-type windage trays are more effective because the oil is broken up into droplets on contact, whereas it tends to splash off a stamped metal tray.
Main cap baffles are another method for controlling sloshing oil. Consisting of a specially designed steel plate (Moroso Part #23000 for small block Chevy, and #23036 for big block Chevy) the main cap baffle fits between the rear main cap and the oil pump and is especially helpful on wheelstanding drag cars. Moroso even offers a neat control kit (#23025 for SB Chevy, and #23036 for BB Chevy) that includes a teflon-coated windage tray, crankshaft scraper, and their main cap baffle.
An important hint to keep in mind when installing a deep oil pan, is that it's much more acceptable to use an oil pump extension rather than installing an extended pick-up tube.
The extension, available from Moroso, fastens between the rear main cap and oil pump to lower it down into the sump. Extending the pick-up tube can lead to possible priming and starvation problems. Desired pick-up to oil pan bottom clearance is 3/8" to 1/2".
Hopefully, this information can help turn your own personal Hurricane Hugo into a much milder tropical storm, and yield more "horses" at the rear wheels to boot.