Crank scraper
08-26-2008, 02:44 AM
#1
Three Wheelin'
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Crank scraper
Can someone enlighten me on crank scrapers for 951 ? Ive herd they are not as easy of an install as it seems. How does the crank scraper compare to the LR oil baffle ?
08-26-2008, 10:19 AM
#2
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The purpose of a crank scraper is to remove the oil that is coming off the crank in a controlled fashion. All the oil that is being fed through the main and connecting rod bearings ends up running off the crank and being flung out in to the crankcase at a fairly high speed (based on engine speed).
Flinging the oil around the crankcase does two things that we would rather not have happen –
1) It creates some drag on the rotating assembly. At 6k rpm is like a blender in there and any oil that is ‘hanging around’ will get caught up in the blender creating a small amount of drag.
2) The oil in the ‘blender’ is getting aerated and this is a more serious problem due to the oiling problems built in to the 944 design.
To work correctly the crank scraper has to be a made with a very tight clearance to the crank and connecting rods. This clearance can be a little different with cast rods, forged rods, aftermarket rods and such. TO expect and ‘off the shelf’ scraper to be a perfect fit is a little unreasonable. Either it will have too much clearance or it will have to be ground to fit. I prefer the ground to fit to make sure I get the best clearance. Most folks don’t like the extra work.
Oil pan baffles are a completely different item – no comparison.
There is only one provider that I know of - IJ crank scrapers
Flinging the oil around the crankcase does two things that we would rather not have happen –
1) It creates some drag on the rotating assembly. At 6k rpm is like a blender in there and any oil that is ‘hanging around’ will get caught up in the blender creating a small amount of drag.
2) The oil in the ‘blender’ is getting aerated and this is a more serious problem due to the oiling problems built in to the 944 design.
To work correctly the crank scraper has to be a made with a very tight clearance to the crank and connecting rods. This clearance can be a little different with cast rods, forged rods, aftermarket rods and such. TO expect and ‘off the shelf’ scraper to be a perfect fit is a little unreasonable. Either it will have too much clearance or it will have to be ground to fit. I prefer the ground to fit to make sure I get the best clearance. Most folks don’t like the extra work.
Oil pan baffles are a completely different item – no comparison.
There is only one provider that I know of - IJ crank scrapers
08-27-2008, 03:24 AM
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I have an IJ scraper that I dont need, I went with a windage tray in the end. Its been ground to fit my previous engine but was never in a running engine 
Let me know if you want to buy it.
Let me know if you want to buy it.
08-27-2008, 11:14 PM
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Three Wheelin'
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i recently installed a windage tray and crank scraper on my race car and I am confident it is an improvement
call pete at RSBARN
www.rsbarn.com
call pete at RSBARN
www.rsbarn.com
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08-28-2008, 04:09 PM
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