Engine Performance This section is for discussion on all engine building related questions.
Sponsored by:
Sponsored by: KPower

Full contact vs non contact crank scraper

Thread Tools
 
Search this Thread
 
Old 04-25-2013, 07:57 AM
  #1  
Elite Member
Thread Starter
iTrader: (2)
 
miata2fast's Avatar
 
Join Date: Aug 2009
Location: Dover, FL
Posts: 3,143
Total Cats: 174
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.

Last edited by miata2fast; 04-25-2013 at 02:54 PM.
miata2fast is offline  
Old 04-25-2013, 08:28 AM
  #2  
Elite Member
iTrader: (8)
 
shlammed's Avatar
 
Join Date: Dec 2008
Location: Kingston, Ontario
Posts: 2,910
Total Cats: 51
Default

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.
shlammed is offline  
Old 04-25-2013, 10:56 AM
  #3  
Elite Member
Thread Starter
iTrader: (2)
 
miata2fast's Avatar
 
Join Date: Aug 2009
Location: Dover, FL
Posts: 3,143
Total Cats: 174
Default

There is a very significant difference in price. Like almost double.
miata2fast is offline  
Old 04-29-2013, 02:53 PM
  #4  
Elite Member
Thread Starter
iTrader: (2)
 
miata2fast's Avatar
 
Join Date: Aug 2009
Location: Dover, FL
Posts: 3,143
Total Cats: 174
Default

Surely some of you guys have some insight on this subject.
miata2fast is offline  
Old 04-29-2013, 02:54 PM
  #5  
Elite Member
iTrader: (1)
 
Leafy's Avatar
 
Join Date: Jun 2012
Location: NH
Posts: 9,479
Total Cats: 104
Default

Originally Posted by miata2fast
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.
Leafy is offline  
Old 04-29-2013, 02:59 PM
  #6  
Elite Member
iTrader: (2)
 
Oscar's Avatar
 
Join Date: Jan 2007
Location: Bolton, UK
Posts: 3,022
Total Cats: 120
Default

Pretty sure this guy is running a I-J scraper.
Oscar is offline  
Old 04-29-2013, 03:00 PM
  #7  
Elite Member
Thread Starter
iTrader: (2)
 
miata2fast's Avatar
 
Join Date: Aug 2009
Location: Dover, FL
Posts: 3,143
Total Cats: 174
Default

Leafy, I would say that is a gross exaggeration. Besides, crank scrapers are used not just on Miatas.
miata2fast is offline  
Old 04-29-2013, 03:11 PM
  #8  
Elite Member
iTrader: (1)
 
Leafy's Avatar
 
Join Date: Jun 2012
Location: NH
Posts: 9,479
Total Cats: 104
Default

Originally Posted by miata2fast
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.
Leafy is offline  
Old 04-29-2013, 03:16 PM
  #9  
Cpt. Slow
iTrader: (25)
 
curly's Avatar
 
Join Date: Oct 2005
Location: Oregon City, OR
Posts: 14,179
Total Cats: 1,129
Default

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.
curly is online now  
Old 04-29-2013, 03:28 PM
  #10  
Elite Member
 
Laur3ns's Avatar
 
Join Date: Mar 2008
Location: Enschede, NL
Posts: 2,053
Total Cats: 12
Default

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.
Laur3ns is offline  
Old 04-30-2013, 04:20 PM
  #11  
Former Vendor
iTrader: (31)
 
Savington's Avatar
 
Join Date: Nov 2006
Location: Sunnyvale, CA
Posts: 15,442
Total Cats: 2,099
Default

Teflon touch-scrapers are a huge pain in the *** to install.
Savington is offline  
Old 04-30-2013, 05:21 PM
  #12  
Elite Member
Thread Starter
iTrader: (2)
 
miata2fast's Avatar
 
Join Date: Aug 2009
Location: Dover, FL
Posts: 3,143
Total Cats: 174
Default

Andrew, what makes it so tough? I would like to know what I am getting into.
miata2fast is offline  
Old 04-30-2013, 05:25 PM
  #13  
Former Vendor
iTrader: (31)
 
Savington's Avatar
 
Join Date: Nov 2006
Location: Sunnyvale, CA
Posts: 15,442
Total Cats: 2,099
Default

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.
Savington is offline  
Old 04-30-2013, 05:28 PM
  #14  
Elite Member
Thread Starter
iTrader: (2)
 
miata2fast's Avatar
 
Join Date: Aug 2009
Location: Dover, FL
Posts: 3,143
Total Cats: 174
Default

Hours and hours? Joy.
miata2fast is offline  
Old 04-30-2013, 05:30 PM
  #15  
Elite Member
Thread Starter
iTrader: (2)
 
miata2fast's Avatar
 
Join Date: Aug 2009
Location: Dover, FL
Posts: 3,143
Total Cats: 174
Default

Thanks for the heads up, I appreciate it.
miata2fast is offline  
Old 04-30-2013, 05:33 PM
  #16  
Former Vendor
iTrader: (31)
 
Savington's Avatar
 
Join Date: Nov 2006
Location: Sunnyvale, CA
Posts: 15,442
Total Cats: 2,099
Default

Originally Posted by miata2fast
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.
Savington is offline  
Old 04-30-2013, 05:37 PM
  #17  
Elite Member
Thread Starter
iTrader: (2)
 
miata2fast's Avatar
 
Join Date: Aug 2009
Location: Dover, FL
Posts: 3,143
Total Cats: 174
Default

What is your prefered method to cut it?
miata2fast is offline  
Old 04-30-2013, 05:45 PM
  #18  
Former Vendor
iTrader: (31)
 
Savington's Avatar
 
Join Date: Nov 2006
Location: Sunnyvale, CA
Posts: 15,442
Total Cats: 2,099
Default

Ideally, you would use a dremel to contour it, but it makes a huge mess and can't be done anywhere near the engine.
Savington is offline  
Old 04-30-2013, 05:50 PM
  #19  
Elite Member
Thread Starter
iTrader: (2)
 
miata2fast's Avatar
 
Join Date: Aug 2009
Location: Dover, FL
Posts: 3,143
Total Cats: 174
Default

I will give it a try. Thanks.
miata2fast is offline  
Old 03-04-2014, 01:24 PM
  #20  
Newb
iTrader: (1)
 
gpzmax's Avatar
 
Join Date: Nov 2010
Posts: 20
Total Cats: 0
Default

Did you ever move forward with this crank scraper project?
gpzmax is offline  
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
Full_Tilt_Boogie
Build Threads
84
04-12-2021 04:21 PM
emilio700
Wheels and Tires
151
06-02-2017 02:36 PM
Quinn
Cars for sale/trade
6
10-23-2016 07:58 AM
Frank_and_Beans
Supercharger Discussion
13
09-12-2016 08:17 PM
Greasyman
General Miata Chat
2
09-28-2015 10:44 AM



Quick Reply: Full contact vs non contact crank scraper



All times are GMT -4. The time now is 12:57 PM.