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Old 04-25-2013, 08:57 AM   #1
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Default Full contact vs non contact crank scraper

There are two flavors of crankshaft scraper, the teflon full contact and the metal non contact.

My question; is there proof the full contact makes more power?

The fact that it touches the crank makes me think that the less expensive non contact version would be better. I know there is more work involved to trim and adjust it correctly.

I have not used them before. Any input would be most appreciated.

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Old 04-25-2013, 09:28 AM   #2
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Having not used them either I personally dont think that anyone will see a signifigant difference in any application with a full contact vs non contact.

The extra percent or 2 of gain in the full contact in reduction of oils on the crank will only relate to the same few percent of the power gain from oils on the crank... which i would think would be minimal.
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Old 04-25-2013, 11:56 AM   #3
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There is a very significant difference in price. Like almost double.
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Old 04-29-2013, 03:53 PM   #4
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Surely some of you guys have some insight on this subject.
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Old 04-29-2013, 03:54 PM   #5
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Quote:
Originally Posted by miata2fast View Post
Surely some of you guys have some insight on this subject.
I wouldnt be surprised if the number of miatas that have crank scrappers could be counted on both hands and that 0% of the people that own them post on the internet.
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Old 04-29-2013, 03:59 PM   #6
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Pretty sure this guy is running a I-J scraper.
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Old 04-29-2013, 04:00 PM   #7
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Leafy, I would say that is a gross exaggeration. Besides, crank scrapers are used not just on Miatas.
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Old 04-29-2013, 04:11 PM   #8
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Quote:
Originally Posted by miata2fast View Post
Leafy, I would say that is a gross exaggeration. Besides, crank scrapers are used not just on Miatas.
I'm just trying to think about the classes in ax and rr that allow crank scrapers but are tight on other allowances so guys will do anything to make an extra 1hp. Maybe F-prod or D-prepared?

And I know crank scrapers are used on not just miatas but they're very rare here. I'm sure they're really common in the american muscle crowd.
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Old 04-29-2013, 04:16 PM   #9
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I have one sitting in the garage for the 1.8 I'm building. I've touched it. That's about the extent of my experience. I did read the directions though. A touchless one sounded easy to install. The teflon scraper one sounded annoying and potentially dangerous to install and tweak. I'd personally go with a touchless one.
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Old 04-29-2013, 04:28 PM   #10
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I've got a teflon scraper but had the shop do all the work.
Can't say what difference it makes, I just hope my engine makes more power and lasts longer. Same with ATI damper I got.
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Old 04-30-2013, 05:20 PM   #11
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Teflon touch-scrapers are a huge pain in the *** to install.
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Old 04-30-2013, 06:21 PM   #12
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Andrew, what makes it so tough? I would like to know what I am getting into.
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Old 04-30-2013, 06:25 PM   #13
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It's hours and hours of cut-fit-cut-fit to get it to just rub everything a little bit. It takes goddamn forever and I'm not convinced that it's worth it unless you're building a rules-restricted engine. Putting one on a street car is an exercise in idiocy.
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Old 04-30-2013, 06:28 PM   #14
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Hours and hours? Joy.
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Old 04-30-2013, 06:30 PM   #15
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Thanks for the heads up, I appreciate it.
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Old 04-30-2013, 06:33 PM   #16
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Quote:
Originally Posted by miata2fast View Post
Hours and hours? Joy.
They come cut pretty tight to the crank counterweights, but they're nowhere near correct at the end of the rod. You have to take 1/4" off the thing in some places, it's not easy to cut, and if you go too big it's ruined.
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Old 04-30-2013, 06:37 PM   #17
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What is your prefered method to cut it?
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Old 04-30-2013, 06:45 PM   #18
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Ideally, you would use a dremel to contour it, but it makes a huge mess and can't be done anywhere near the engine.
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Old 04-30-2013, 06:50 PM   #19
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I will give it a try. Thanks.
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Old 03-04-2014, 02:24 PM   #20
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Did you ever move forward with this crank scraper project?
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