Go Back  Offshoreonly.com > General Discussion > General Boating Discussion
2 ? 3 ? OR 4 Stage water pump? >

2 ? 3 ? OR 4 Stage water pump?

Like Tree0Likes

2 ? 3 ? OR 4 Stage water pump?


Old 08-09-2005, 01:59 PM
VIP Member
Thread Starter
Join Date: Mar 2002
My Boat: yeah....that one
Posts: 2,749
Default 2 ? 3 ? OR 4 Stage water pump?

what would be the best and why and what is the best way to plumb them......

supercharged,innercooled, and bell housing coolers.....
SLINGSHOT is offline  
Reply With Quote
Old 08-09-2005, 03:34 PM
Official OSO boat whore
Charter Member
iTrader: (2)
Join Date: Oct 2000
Location: Mequon, WI
My Boat: 8' row boat
Posts: 6,157
Default Re: 2 ? 3 ? OR 4 Stage water pump?

Do two water pickups. Preferably transom pickups. One will be dedicated to the engine with a mascerator type strainer. The second pickup will go to a mini mascerator type strainer. This way, the water will be cut off when the boat is off plane. This will prevent the fuel from condensing on the cooler. I would use a stock merc water pump with stock merc oil coolers. This way you can use preformed hoses and the merc brackets. When they are custom painted you get a nice clean installation. I know KE makes a multi-stage water pump, but has anybody ever really needed one? A stock waterpump is nice because you can get a impeller just about anywhere.
Cord is offline  
Reply With Quote
Old 08-09-2005, 06:28 PM
44MTI's Avatar
Join Date: May 2003
Location: E-Dock
My Boat: 08' 44 MTI
Posts: 3,129
Default Re: 2 ? 3 ? OR 4 Stage water pump?

Most high performance builder use a 2 stage. One going to each bellhousing cooler then each bellhousing cooler has a line running forward to a dual intlet crossover. You will need a bellhousing that has an inlet and outlet for each cooler. You can also have a bung welded into each cooler in you only have one outlet in each.This what I did this winter.

You can also have a two stage water pump that has one outlet that feeds the oil coolers with a single inlet crossover.This is the normal merc 900SC configuraton.
In retrospect I would probably go with the second option if your not already plumbed with a dual inlet crossover. I spent over $1500 on two new crossovers and stainless braided lines to plumb them.

Also KE dual stage water pumps use standard merc impellers.

Last edited by 44MTI; 08-09-2005 at 06:31 PM.
44MTI is offline  
Reply With Quote
Old 08-09-2005, 08:30 PM
Brad Zastrow's Avatar
Join Date: Jun 2001
Location: McHenry, Illinois
Posts: 2,253
Default Re: 2 ? 3 ? OR 4 Stage water pump?

Having a seperate water pickup for the intercooler has a host of issues I can not get comfortable with. For one you will need a blow off valve to control the water pressure spikes or risk the possiblity of blowing the cooler. Second problem is a big problem, no water in the intercooler and it will get real hot and likely crack with the introduction of cold water when you take off.

I use a two stage pump. One stage for the engine and one for the intercooler. I also use a Stainless Marine intercooler sea strainer just before the intercooler. It has a fine mesh filter to prevent small bits plugging up the cooler.

Last edited by Brad Zastrow; 08-09-2005 at 08:35 PM.
Brad Zastrow is offline  
Reply With Quote
Related Topics
Thread Starter
Last Post
General Q & A
08-19-2007 10:30 PM
General Q & A
05-29-2007 10:12 PM
General Q & A
12-29-2006 08:45 AM
General Q & A
09-02-2003 01:04 PM

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

Quick Reply: 2 ? 3 ? OR 4 Stage water pump?

OSO Sponsor
OSO Advertiser
OSO Advertiser
OSO Advertiser