Crank Scrapers and the Tea Leaf Paradox

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DeepFriar

DeepFriar

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The recent discussion of oil levels and the effects on actual lubrication led me to look further at something I had almost forgotten about from the "old days", crank scrapers. Distinct from windage trays, srapers are another method of oil control in the oil cloud. The link below is to a company that has done a lot of work in the area and contains some references and patents that may be of interest.

http://www.crank-scrapers.com/What is a crank-scraper.html

http://www.performance928.com/cgi-bin/pa...ass_parent=1128
 
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That Teflon scraper is neat. I remember hours with a die grinder tweeking a scraper to fit. One of my first big block builds had a 7 qt oil capacity, and 10 seconds at 7500 RPM would suck the oil pan dry to where the oil pressure gauge would bounce.

Smokey Yunick had a section on oil control in one of his books. He compared it to a big wad of taffy twisting around on the crank at high (8K+ rpm) speeds. He figured a way to put the illumination inside the crankcase to get a better view.
 
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The guy was a genius. The visible aeration in that video, and the loss of pressure it represents, is flat scary. Accusumps can bandaid more than one problem I guess. I'd just rather try to deal with the problem at the source and the scrapers came to mind.
 
Oil 'control' in engines' reciprocating assemblies and wet sumps is fascinating to me.

With all the oil that's circulating upstairs, it's a wonder why more engines don't unglue themselves during
HPDEs, magazine track tests, etc. when throwing serious yaw and pitch dynamics into the mix.

My morning espresso sloshes up the side of its cup ~45º at 1g of lateral or longitudinal force.
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Test of LS oil pressure fluctuations during circuit motoring:
http://www.improvedracing.com/images/testdata/Stock_vs_EGM-204_All.pdf
 
Originally Posted By: splinter


Test of LS oil pressure fluctuations during circuit motoring:
http://www.improvedracing.com/images/testdata/Stock_vs_EGM-204_All.pdf


The graphs show tremendous improvement for the new tray don't they? They also show something else that may somewhat mitigate the lower pressure while in corner at high G-load. Lower revs due to lower speeds in much of the turns might (I'm guessing) mean lower stress on reciprocating "junctions" for lack of a better term from my weak mind. You see the RPMs fall and the pressure with it of course. More than just one contributing factor (as almost always). I too am fascinated by the sheer (no pun intended) violence going on in there.
 
Originally Posted By: DeepFriar
Originally Posted By: splinter


Test of LS oil pressure fluctuations during circuit motoring:
http://www.improvedracing.com/images/testdata/Stock_vs_EGM-204_All.pdf


The graphs show tremendous improvement for the new tray don't they? They also show something else that may somewhat mitigate the lower pressure while in corner at high G-load. Lower revs due to lower speeds in much of the turns might (I'm guessing) mean lower stress on reciprocating "junctions" for lack of a better term from my weak mind. You see the RPMs fall and the pressure with it of course. More than just one contributing factor (as almost always). I too am fascinated by the sheer (no pun intended) violence going on in there.


That said, Improved Racing as a company, DOES make some of the very finest internal, 'oil control' products for the LSx series engines.
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