Windage tray vs. crank scraper?

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12
Location
Austin, TX
I'm new to this forum, and was surprised to find that nothing came up when I did a search on windage trays. I'm interested in them because if I decide to replace the rod bearings on my 1992 Porsche 968, I may go ahead and install one while I have everything apart. So, I was wondering if someone could provide an explanation of exactly what a windage tray does, how it works, how it's differnt from a crank scraper, and how (as some manufacturers claim) it can reduce oil temperature. Thanks.
 
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3,742
Location
Northern California, USA
your Porsche may already have some sort of windage tray setup. A crank scraper is something different. For SB Chevy's the scraper needs to be hand fitted to about .005" of the crank counter weights. I don't know how precise the Porsche crank is. A windage tray stops the oil that is being thrown off the crank from bouncing back, off the oil pan, onto the cylinder walls and causing excessive oil consumption, more friction (oil and compression ring hydroplaning), and possibly less compression. A crank scraper just scrapes the excess oil from the crank. Since your motor is horizontally opposed. I dont think you can have either. the scraper and tray are for V-8's
 

Porsche968

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12
Location
Austin, TX
 Originally Posted By: Loobed
your Porsche may already have some sort of windage tray setup. A crank scraper is something different. For SB Chevy's the scraper needs to be hand fitted to about .005" of the crank counter weights. I don't know how precise the Porsche crank is. A windage tray stops the oil that is being thrown off the crank from bouncing back, off the oil pan, onto the cylinder walls and causing excessive oil consumption, more friction (oil and compression ring hydroplaning), and possibly less compression. A crank scraper just scrapes the excess oil from the crank. Since your motor is horizontally opposed. I dont think you can have either. the scraper and tray are for V-8's
Actually, my engine is a 3.0 liter straight four, and a crank scraper and windage tray (which includes the scraper) are available in the aftermarket. I'd just like to have a better understanding of what they do, and how they can benefit engine longetivity through their interaction with the lubrication system, before I buy one or the other. Thanks.
 

Porsche968

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12
Location
Austin, TX
 Originally Posted By: tom slick
do you run your car at the track? do you drive at sustained high rpm?
Yes, I run the car at the track, though I haven't been in awhile due to (hopefully temporary) financial considerations. The track I run at is short, with a series of tight, very technical turns; it stays in 3rd gear most of the way around. So to answer your question, it doesn't really sustain high rpm's; I just take it up to redline once a lap for the instant before the 2nd-to-3rd upshift. I think the tires take much more of a beating than the engine. I guess you're asking because of consideration over how much sloshing may be occurring in the pan (it has baffles, which I would hope hould take car of that). However, longer term, as I progress with my driving, I will be graduating to longer sections of the track, with major elevation changes, higher speeds, etc., so the engine should see much more severe use in its future. Best case, in late 2009, but most likely in 2010.
 
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