A windage tray will not only keep your crankshaft from dipping into your oil at high rpm (causing parasitic drag and foaming your oil, which in some engines can cause cavitation and therfore oil starvation and eventually engine failure from it) it also keeps your oil from sloshing during hard acceleration and cornering, causing the same problems. A crank scraper removes excess oil from the crankshaft. If you look at a scraper, vs. A windage tray, they are completely different animals. Windage trays should be on all engines in some form. Crank scrapers belong on hardcore track cars. It costs a manufacturer millions to design and build an engine, especially one as durable and with as long a production run as the BMW inline 6. It wouldn't be there if it didn't need to be for one reason or another. Some of the external, emissions and drivability parts along with things designed with nvh in mind may be debatable, but am internal engine component is not. If I were spending my hard earned dollars to put an engine in my car, i would take my oil pan to my machinist, along with the oil pan off of the new motor, and tell him to make a secure attaching point on your stock pan at the same distance from the pan rail as it is on the pan off of the new motor. It should cost less than $100 and could save you premature engine failure. Worth it in my book.
Last edited by hiroshima; 12-03-2012 at 08:13 PM.