Go Back  Offshoreonly.com > General Discussion > General Boating Discussion
525 EFI Water Pressure Relief Valve >

525 EFI Water Pressure Relief Valve

Notices

525 EFI Water Pressure Relief Valve

Old 06-11-2013, 12:41 AM
  #1  
Registered
Thread Starter
 
Join Date: Jul 2009
Posts: 18
Likes: 0
Received 0 Likes on 0 Posts
Default 525 EFI Water Pressure Relief Valve

I have a 2005 29' Fountain with a 525 EFI. Water pressure is above 40 PSI over 4000 rpm. There's no blockage issue, and I'm thinking about installing pressure relief valve. Any one else install one? Any recommendations? Thanks!
Sierra Azul is offline  
Old 06-11-2013, 06:25 AM
  #2  
Registered
iTrader: (1)
 
Join Date: Jun 2004
Location: Omaha, Nebraska. Boat on the Mighty Mo! Longest river in the USA!
Posts: 1,944
Received 37 Likes on 23 Posts
Default

Lots of people run them. 40 psi is too high. I have one pricy plastic mercrusier one, and a nice metal one from C.P. performance. There are a couple in the swamp shop. Cheap and easy to install, your only talking about hoses. Mine never go over 20 psi.
1BIGJIM is offline  
Old 06-11-2013, 06:44 AM
  #3  
Registered
iTrader: (6)
 
Join Date: Oct 2005
Location: Clarkston, Michigan
Posts: 5,825
Received 607 Likes on 275 Posts
Default

Mercury manual says you are OK up to 43 psi with the 525. I installed a pop-off valve on mine but have removed it. The 525 likes more than 20-25. I try to hold mine at 35-40 when running hard. I welded up and reshaped the inlet on the Imco shorty. If the pressure shoots too high I can lower it by bumping the trim up. If a relief valve sticks open on a hard run it could be disastrous. Brownie (Alan Brown) himself came onto a thread that I started about this same thing and advised against running a relief valve. With raw water cooling it is much more important to keep pressure around 20-25.
thirdchildhood is offline  
Old 06-11-2013, 07:46 PM
  #4  
Registered
iTrader: (1)
 
Join Date: Jun 2004
Location: Omaha, Nebraska. Boat on the Mighty Mo! Longest river in the USA!
Posts: 1,944
Received 37 Likes on 23 Posts
Default

Yes the manual says up to 40 because they had problems cooling the headers when they first came out with the 525sc. Do a search on Water Pressure in the title, you can read the rest of the night. To much pressure and you can push water around the gaskets.
1BIGJIM is offline  
Old 06-11-2013, 08:44 PM
  #5  
VIP Member
VIP Member
 
Join Date: Oct 2006
Posts: 210
Likes: 0
Received 0 Likes on 0 Posts
Default

I use the merc relief valves. Come stock with 30 lb spring, should be plenty for most applications. I ran the exit hoses out the side of the hull, that way it is easy to check if they are working correctly. Working ok for 3 years now.
Sport 280 is offline  
Old 06-11-2013, 09:00 PM
  #6  
Registered
iTrader: (6)
 
Join Date: Oct 2005
Location: Clarkston, Michigan
Posts: 5,825
Received 607 Likes on 275 Posts
Default

Originally Posted by 1BIGJIM
Yes the manual says up to 40 because they had problems cooling the headers when they first came out with the 525sc. Do a search on Water Pressure in the title, you can read the rest of the night. To much pressure and you can push water around the gaskets.
It's closed cooled. The water doesn't go around gaskets, it just flows through the various coolers. Mercury service manual says 43 psi max. Not up to 40. I regularly run 40 psi. This is an '07 vintage engine.

Last edited by thirdchildhood; 06-11-2013 at 09:02 PM.
thirdchildhood is offline  
Old 06-11-2013, 09:23 PM
  #7  
Registered
 
Back4More's Avatar
 
Join Date: Feb 2002
Location: Lake Michigan
Posts: 6,627
Likes: 0
Received 0 Likes on 0 Posts
Default

http://www.offshoreonly.com/forums/f...ief-valve.html
Back4More 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.