Go Back  Offshoreonly.com > Technical > General Q & A
merc high altitude pulley? >

merc high altitude pulley?

Notices

merc high altitude pulley?

Old 02-24-2015, 08:20 AM
  #1  
Registered
Thread Starter
 
Join Date: May 2009
Location: Toms River NJ
Posts: 177
Likes: 0
Received 0 Likes on 0 Posts
Default merc high altitude pulley?

Does anybody know the diameter of the high altitude smaller pulley for the 525sc? Tried searching for it and can't find it, thx all
JerseyOutlaw is offline  
Old 02-24-2015, 05:14 PM
  #2  
Registered
iTrader: (1)
 
Join Date: Aug 2013
Location: Newark, DE
Posts: 621
Likes: 0
Received 0 Likes on 0 Posts
Default

3"
ealesh33 is offline  
Old 02-25-2015, 12:25 PM
  #3  
Registered
 
Join Date: Nov 2005
Location: Wayland, MI
Posts: 387
Likes: 0
Received 0 Likes on 0 Posts
Default

Good luck finding one. I have never heard of a 3" splined pulley, assuming it has the Merc shaft. I have seen splined 2.85" pulleys though. If the shaft has a keyway (automotive style) there are more choices in pulley sizes available.

Last edited by Old Navy; 02-25-2015 at 12:27 PM. Reason: spelling
Old Navy is offline  
Old 02-25-2015, 03:14 PM
  #4  
Registered
iTrader: (1)
 
Join Date: Aug 2013
Location: Newark, DE
Posts: 621
Likes: 0
Received 0 Likes on 0 Posts
Default

Well Old Navy I have that unicorn lol. 3" pulley for the 177 with a merc shaft. 525sc stock pulley size is 3.25", I got the 3" pulley and put it on August of this past year and ran it for the remainder of the season. I saw a 2psi increase with it.

Last edited by ealesh33; 02-25-2015 at 03:16 PM.
ealesh33 is offline  
Old 02-25-2015, 06:51 PM
  #5  
Charter Member # 55
Charter Member
 
Griff's Avatar
 
Join Date: Oct 2000
Location: Omaha/LOTO
Posts: 19,548
Received 1,812 Likes on 902 Posts
Default

I know somebody looking for a smaller than stock 525SC upper pulley if anybody has any leads.
The smallest I ever heard of was 2.75" There used to be quite a few places that sold smaller ones, but that was years ago.
I think I had a 2.88" on my 525SC and it made just under 8# of boost.
Griff is offline  
Old 02-25-2015, 08:46 PM
  #6  
Registered
iTrader: (1)
 
Join Date: Aug 2013
Location: Newark, DE
Posts: 621
Likes: 0
Received 0 Likes on 0 Posts
Default

Makes sense Griff I was seeing 7psi maybe a touch more with the 3" pulley.
ealesh33 is offline  
Old 02-25-2015, 09:04 PM
  #7  
Registered
iTrader: (2)
 
Join Date: Aug 2011
Location: bel air, md
Posts: 2,733
Likes: 0
Received 5 Likes on 5 Posts
Default

Put it on a lathe and make it as small as you want
Black Baja is offline  
Old 02-26-2015, 05:34 AM
  #8  
Registered
 
Join Date: Nov 2005
Location: Wayland, MI
Posts: 387
Likes: 0
Received 0 Likes on 0 Posts
Default

Originally Posted by ealesh33
Well Old Navy I have that unicorn lol. 3" pulley for the 177 with a merc shaft. 525sc stock pulley size is 3.25", I got the 3" pulley and put it on August of this past year and ran it for the remainder of the season. I saw a 2psi increase with it.
I think it is the 3.10 pulley, but close enough for discussion.
Old Navy is offline  
Old 02-26-2015, 07:17 AM
  #9  
Registered
iTrader: (1)
 
Join Date: Aug 2013
Location: Newark, DE
Posts: 621
Likes: 0
Received 0 Likes on 0 Posts
Default

I have not measured it with a pair of micrometers to get the EXACT size, but have with a tape measure and I remember it being 3". When i go down to my builder again I will measure with mics and see exactly what it is.
ealesh33 is offline  
Old 03-15-2015, 04:44 PM
  #10  
Registered
iTrader: (1)
 
Join Date: Aug 2013
Location: Newark, DE
Posts: 621
Likes: 0
Received 0 Likes on 0 Posts
Default

I measured the pulley and it is 3", however I found out it is a cut down stock pulley. I got the pulley from a local guy, and by complete chance my dyno operator is the one who cut the pulley down for the guy who I bought it from lol. He recognized it when they were setting it up on the dyno and he asked me where i got it, when I told him he said he knew he recognized it and that he cut it down from a stock one. So I am not sure what size the low altitude pulley is, but if you take a stock 3.25" pulley and have it cut down to 3" you'll increase boost around 2psi.
ealesh33 is offline  

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On


Contact Us - Archive - Advertising - Cookie Policy - Privacy Statement - Terms of Service

Copyright © 2024 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.