has anyone tried these teflon crankscrapers seem like a really good setup just wanted to get some opinion input http://crank-scrapers.com/7M-Teflon.jpg . The Teflon ones they got go for $150 the non teflon are $50
Crank scraper of choice
- Thread starter cruzinbill
- Start date
CB: I have the very first Teflon 7M scraper in my new motor I've just built (It's actually the one in that pic)
Haven't run it yet but it's a good product that's not too expensive!
Haven't run it yet but it's a good product that's not too expensive!
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i think they just scrape off the excess oil off the crank.. but i dunno,,
from thier site..
During normal engine operation a significant amount of oil adheres to or becomes entrained in a cloud surrounding the spinning bottom end. This oil eats up horsepower your engine is making by increasing the rotating mass and also creating parasitic drag. A crank scraper mechanically strips off excess oil by coming close to, but not touching*, the moving crankshaft and rods. It also interferes with the pressure differential that draws oil into the so-called windage cloud.
from thier site..
During normal engine operation a significant amount of oil adheres to or becomes entrained in a cloud surrounding the spinning bottom end. This oil eats up horsepower your engine is making by increasing the rotating mass and also creating parasitic drag. A crank scraper mechanically strips off excess oil by coming close to, but not touching*, the moving crankshaft and rods. It also interferes with the pressure differential that draws oil into the so-called windage cloud.
Nick: Typical scrapers are set .040"/1mm away from the crank so don't actually touch and shear the oil away through surface tension, then Oil then returns to the Pan instead of whipping around with the crank.
The Teflon Scraper takes this one step further and actually contacts the Crank Counterweights to remove as much Oil as possible returning it to the Pan,
I don't really understand what you think is going to "break off" ?
The Teflon Scraper takes this one step further and actually contacts the Crank Counterweights to remove as much Oil as possible returning it to the Pan,
I don't really understand what you think is going to "break off" ?
thanks IJ i was wondering if it was worth the other 100 to get the teflon, it seems like it is since it will mate perfectly to your crank
CB: It takes a LOT of hand fitting to get it to mate to the crank as it arrives with oversize Teflon inserts!
The guys at Ishihara-Johnson were great to deal with when I approached them to make a Teflon 7M one!
The guys at Ishihara-Johnson were great to deal with when I approached them to make a Teflon 7M one!
IJ. said:
What is the best way to get it fit? just remove a little bit at a time? and what is the best way to remove the extra teflon?
do you have to shave down the teflon yourself to fit tho or will it do it on its own with engine rotaion?
Loki: I used a Stone in the Die Grinder (Big arse Dremel thing) to take the bulk out for the Rods to clear then used a mini Air Belt sander I have to Chamfer the leading edge and finally a machinists hand held Deburring knife to clean up all the edges!
Nick: I wasn't being a smartarse or anything just trying to work out what your concerns were so I could answer better.
The Teflon is surprisingly strong and being Teflon by it's very nature it's slippery stuff so wouldn't add much in the way of drag.
It should free up much more power from the added weight of Oil on the Crank flying around in the block than it would consume in drag
The Teflon is surprisingly strong and being Teflon by it's very nature it's slippery stuff so wouldn't add much in the way of drag.
It should free up much more power from the added weight of Oil on the Crank flying around in the block than it would consume in drag
That sounds like a good idea. Wouldnt want to waste energy spinning oil around in a tank when you dont have to. I am definetely going to have to look into a crank scraper for my rebuild. I am almost ready to pull my engine now but rainstorms around here keep delaying it. Also I am having trouble finding a good machinist. Thats ok though because it gives me more time to gather information and money.
Yep I figured the Oil would be better down around the pickup than floating around bouncing off the Crank and having it whipped into froth 
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Yes IJ good info let us know how it works out when you get it started up, i think i will go with the normal one for now i just feel to lazy to deal with shaping the teflon... lol yah ill probly get it anyway
Figgie: Nah I figured with the GrpA Pan/Scraper combination the bulk of the oil will always be much lower than the Crank so it was a waste of time/money!
If I was doing it again though I'd put the crank in the Lathe and skim the Counterweights so they were all a constant diameter as the Scraper only makes contact in one place. (they're a bit like BIG low lift cams in shape)
If I was doing it again though I'd put the crank in the Lathe and skim the Counterweights so they were all a constant diameter as the Scraper only makes contact in one place. (they're a bit like BIG low lift cams in shape)