Ill try and answer that so you'll see the advantage of using one, first its not going to make you a great deal of extra horsepower, it MIGHT increase your rear wheel power 3-5 hp,in most applications, or a bit more if used with a crank scraper in combination, but what it will more than likely do IF its correctly installed with a matching baffled high capacity oil pan which along with a crank scraper, is become part of a total system to greatly increase oil flow control and maintain much more consistent oil flow and consistent pressure to the bearings.
the main function of the windage tray or screen is to help maintain a higher volume of oil covering the oil pump pick-up, and prevent oil from being whipped into a froth containing air which will reduce bearing cooling and hydraulic surface support on the moving parts. its properly installed use , tends to speed the flow of returning oil to the sump, and reduce the oil in the crank case dragged around the lower engine with the spinning crank assembly, and reduce the air or foam in the oil pan sump.
the question always seems to come up about, "if you have a baffled high capacity oil pan, if you really need a windage tray?"
, the answer will vary with the application and the cars intended use, and average engine rpm, the engines run at, and in my opinion,for a street performance application, a correctly built 7-8 quart baffled oil pans probably fine, below about 6000rpm, without adding an additional windage screen,but generally youll see more consistent oil pressure with one installed, even well below that rpm level.
but I certainly would instal a windage screen on something like a road race car, even with a high capacity baffled oil pan, but in an application like that I,d also suggest an oil cooler too!
(provided your stuck with a wet sump oil pan, obviously a dry sump oil system with a 4 stage scavenging pump would be advantageous)
viewtopic.php?f=54&t=1058&p=2016&hilit=drysump#p2016
Ive placed both scat and eagle crank shafts next to a similar chevy OEM crank, and carefully examined all three and in my opinion the eagle crank was the least well finished with the scat crank being the best, now obviously all three manufacturers have made several grades of cranks and Ive used a truck load of SCAT and FORGED CHEVY crank shafts over the years with good results






knife edging a cranks counter weights BEFORE balancing the assembly reduces windage looses but can also make balancing the assembly more expensive

HERES A STOCK BIG BLOCK CHEVY WINDAGE TRAY (BARELY FUNCTIONAL BUT DIRT CHEAP)


HERES ONE THAT WORKS


http://www.rehermorrison.com.previewdns ... _21049.pdf
above is one type of windage tray, it bolts in most cases to extended main cap bolts and is located about 1/8" outside the arc of the spinning crank and rods,
HERES AN AFTERMARKET DESIGN THATS MORE EXPENSIVE BUT MORE EFFECTIVE


oil trapped or dragged by the spinning assembly passes over it surface, and louvers or a screen shears off oil and routes it efficiently into the oil pan, rather than constantly being dragged around with the spinning assembly like liquid in a blender.
1/8" works really well, , now IM sure if its a bit closer at .080- .100 it won,t matter much, remember the idea is to have the spinning crank assembly passing over the windage trays surface acting as a pump impeller to efficiently sweep the surface oil falling from the upper engine into the sump, quickly and efficiently, rather than allowing it to follow the crank as it rotates around constantly in the lower engine.
Adding a correctly installed and designed windage tray or screen assembly usually reduces drag on the crank and can result in a 3-5 hp increase but its main function is far more effective , return of oil to the sump, thus reducing the probability of oil pressure/supply problems, to the bearings, and over whelming the oil rings. Oil that's being whipped into a frothy oil/air mix, by the rotating assembly won,t provide the required lubrication, cooling and bearing protection
keep in mind the main function of a windage screen when its properly installed is to speed the return of oil flowing back from the upper engine and oil caught by the rotating assembly , back into the lower oil pan for rapid reuse. your trying to maintain oil levels in the sump for a dependable and consistent control of oil flow to the bearings by insuring return rates and oil volume around the oil pump pick-up.
your also reducing pumping losses as your reducing the weight of oil the spinning rotating assembly is dragging around in the lower engine as the spinning assembly acts a bit like a oil pump impeller as it sweeps oil into the sump, as it passes oil thrown from the crank, which is being more efficiently directed into the sump. its use is not so much about power gains as it is about maintaining total oil control
READ THIS LINK
http://www.carcraft.com/techarticles/cc ... index.html


running an engine like this picture above ,with just an open oil pan, tends to waste 4-8 hp or more at higher rpms and may over load the rings with oil on the cylinder walls, and cause the bearings to get intermittent oil pressure


installing the combo of crank scraper and windage tray allows you to regain 4-8 hp,too have much better controlled ,& dependable lubrication and oil pressure and have less chance for bearing damage from oil starvation
without a windage screen oil in the sump is frequently whipped into a froth at high rpms reducing bearing support and cooling

with a windage screen oil in the sump is protected from being whipped into a froth at high rpms, thus increasing bearing support and cooling, so bearings tend to last a good deal longer

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another


some oil pans have them built into them,
the purpose is to BOTH speed the return of oil to the sump from the oil spinning off the bearings and rods/crank ETC. and to isolate the oil in the sump from the effects of the spinning crank acting as an impeller.
without a windage tray or screen the spinning crank assembly tends to beat the oil in the sump into a froth of oil and air at high rpm levels
with the windage screen properly installed the oil pushed over the surface is sheared off and thrown into the sump for reuse at the oil pump at a faster rate and partially isolated from the impeller effect of the spinning crank assembly.
keep in mind pushing/DRAGGING the oil around with the spinning crank assembly takes HORSEPOWER so minimizing the volume has the benefit of freeing up a bit of hp AND aiding or adding too the oil pumps supply of oil to the bearings in the sump as it speeds its return to the oil pump.
the correctly designed windage tray or SCREEN and CRANK SCRAPPER assembly doesn,t prevent oil from falling on the spinning crank, but centrifugal force throws that oil to the outside of the arc, where, its dragged around, and forced into the sump, what it does is provide a very effective flow of that oil back into the sump as the spinning crank acts as an impeller and drags the oil 1/2 way around its rotation and throws it into the sump for re-use rather than having the oil constantly and endlessly dragged around in a 360 degree circle by the spinning crank assembly, that far more efficient flow of oil limits the amount of drag the crank sees, and speeds the oil back where its useful, vs allowing it to be beat to a froth, and dragged constantly with the crank.
while its true that pumping oil, falling from the lifter gallery , around the crankcase with the rotating assembly, adds some drag and costs some hp, adding a correctly fitted windage screen and high capacity baffled oil pan to route that draining oil back to the sump efficiently minimizes the loss, and your forgetting that oil spray helps lube the rings and cam and cools the pistons, Ive seen more problems caused than solved restricting oil drain back.
I don,t restrict oil drain back, I use a windage screen and high capacity baffled oil pan designed to route the oil efficiently back to the sump, in theory at least the vast majority of the return oil flow will only make it dragged around about 240 degrees of the cranks rotational arc ONCE, but then Ive always prized absolute durability and dependability over getting the last possible 4-5 hp from an engine if it might lower that dependability, keep in mind the main gain in use of a baffled oil pan,windage screen and crank scraper used as a combo,is in effectively controlling and speeding oil return to the oil pump,and oil pan sump so you never have oil pressure fluctuation under high rpm or g-force loads, that a stock oil pan is subject too in a high performance environment, its not a big horse power gain, but it can be a huge improvement in engine durability

the milodon style windage screens work more effectively,
http://www.milodon.com/oil-system/winda ... -studs.asp
as they drain oil to the sump faster

ESPECIALLY WITH A CAREFULLY FITTED CRANK SCRAPPER ADDED

I would not be all that concerned with measuring the oil level , in an oil pan by pouring oil in it to determine if the oil will be hitting the crank during engine operation.
remember theres about 2 quarts in the blocks oil passage ways, heads and lifter gallery at higher rpms and a good windage tray and crank scrapper, installed in a baffled oil pan, go a long way toward better oil control. a decent 7-8 quart rated oil pan with 6-7-8 quarts in it with a well designed windage tray and baffles will maintain oil pressure.
looking at the pictures suggests you should be fine, but I always suggest use of an oil windage screen minimum


http://www.summitracing.com/parts/MIL-32255/?rtype=10


the high temp magnets tend to stay right where they are placed, in a steel oil pan, but youll need J&B weld in an aluminum oil pan application, in my experience PROVIDED you use the ones designed to function in the heat range they can tolerate, just be aware you don,t want them too close to swinging oil baffle door flaps in a baffled oil pan as they have been known to hold those swinging gates open or closed if placed in the wrong areas,
example,
If this is an oil pan with this oil control baffle wall installed ,with steel oil control baffle doors, placing a magnet above these baffle doors is almost sure to prevent them from closing or placing one below is a sure way to keep them locked closed, thats one reason light weight ALUMINUM baffle doors are preferred,even in steel oil pans, the oil sloshing moves them, from open to closed as designed easily , limiting oil flow to movement in the direction desired, and magnets don,t tend to limit movement


read related threads
viewtopic.php?f=54&t=64
viewtopic.php?f=54&t=2187
viewtopic.php?f=54&t=65
viewtopic.php?f=54&t=1800

LSI/LS6 OIL ROUTING THRU BLOCK

BTW a contour gauge makes fabricating an effective oil scrapper far easier, and having it welded to the oil pans windage screen after careful fitting helps also. its not mandatory but its useful, the object of a crank scraper is of course to restrict oil leaving the pan by being dragged around with the counter weights , having a crank scrapper shears off the oil forcing it to drop into the sump, oil flowing across a windage screen surface tends to get thrown with centrifugal force thru the windage screen where it quickly drains into the sump.
http://www.amazon.com/General-Tool-833- ... B000E36098
http://www.amazon.com/Outset-QS71-Stain ... d_sbs_lg_6

LOOKING AROUND FOR SOURCES OF CHEAP MATERIALS ,THATS a GREAT IDEA!
heres another source for materials that might be faster and cheaper, depending obviously on what your trying to build,
THESE LINKS ARE WORTH READING THRU
viewtopic.php?f=44&t=10490&p=44215#p44215
http://www.chevelles.com/techref/ScreenInstall.pdf
http://victorylibrary.com/mopar/baffle.htm
viewtopic.php?f=52&t=6491
http://www.milodon.com/oil-system/oil-pumps.asp
http://rehermorrison.com/tech-talk-74-t ... liability/
viewtopic.php?f=54&t=2187
http://www.circletrack.com/techarticles ... index.html