Like Tree0Likes

500 hp no water pumps?

Reply
Old 02-19-2010, 08:21 PM
  #1
Registered
Thread Starter
 
Join Date: Jan 2010
Posts: 138
Default 500 hp no water pumps?

I am ready to purchase a 1999 35 fountain w/500 hps-NO waterpumps just a by-pass(ss)pipe-is this ok? what reasons for taking off pumps? future issues?
ratedx is offline  
Reply With Quote
Old 02-19-2010, 08:45 PM
  #2
Registered
 
Join Date: Sep 2007
Location: Essex Junction, Vermont
My Boats: Eclipse 233 sbc 383 dry piped
Posts: 303
Default

There's no such thing as an engine with no water pumps. Those engines have raw water pumps located on the lower left of the engine as you face the front of them belt driven. The cross overs (by-pass) are very common on performance big blocks. There's no need to double up on water pumps unless you're trying to control water flow for some reason. (automotive type pumps will slow flow). All that being said it might be good to have a marine mechanic check it out before you buy.
Sunshadow is offline  
Reply With Quote
Old 02-19-2010, 08:49 PM
  #3
Ginger or Mary Ann?
Charter Member
Trade Score: (1)
 
US1 Fountain's Avatar
 
Join Date: Oct 2000
Location: Lafayette. IN
Posts: 10,868
Default

Cross overs can create more problems than they are worth. The circulating pumps are trouble free sytems. Do you want to turn key or turn wrench?
__________________
Some people are like Slinkies - Not really good for anything, but they
bring a smile to your face when pushed down the stairs.
US1 Fountain is offline  
Reply With Quote
Old 02-19-2010, 08:51 PM
  #4
Registered
Thread Starter
 
Join Date: Jan 2010
Posts: 138
Default

impellers? is that the pump you are saying
ratedx is offline  
Reply With Quote
Old 02-19-2010, 08:57 PM
  #5
Ginger or Mary Ann?
Charter Member
Trade Score: (1)
 
US1 Fountain's Avatar
 
Join Date: Oct 2000
Location: Lafayette. IN
Posts: 10,868
Default

The impellor is part of the sea (raw) water pump, which is the belt driven pump Sunshadow mentioned. The circulating pump is your regular automotive looking pump on the front of the motor. Which in this case has been replaced by the cross over setup. You still need the sea water pump regardless.
__________________
Some people are like Slinkies - Not really good for anything, but they
bring a smile to your face when pushed down the stairs.

Last edited by US1 Fountain; 02-19-2010 at 08:59 PM.
US1 Fountain is offline  
Reply With Quote
Old 02-19-2010, 09:01 PM
  #6
Charter Member
Charter Member
 
bowtie's Avatar
 
Join Date: Jan 2001
Location: New Jersey
Posts: 665
Default

Talking about 2 different things here guys. The crossover replaces the circulator pump, often refered to as the water pump on cars. You need the raw water pump, which is the impeller pump sucking in the water to cool the engine. You don't need the circulator pump because the Bravo raw water pump has enough pressure to circulate the water also.
bowtie is offline  
Reply With Quote
Old 02-19-2010, 09:27 PM
  #7
Registered
Thread Starter
 
Join Date: Jan 2010
Posts: 138
Default

mercruiser only comes w/circulating pump correct? w/o circ. pump does it add more hp? or just better cooling?
ratedx is offline  
Reply With Quote
Old 02-19-2010, 09:48 PM
  #8
Registered
 
Join Date: Jan 2001
Location: Cincinnati, OH
My Boats: 2012 Proboat MG29
Posts: 710
Default

One reason that some people change to a crossover is that it is a lot cheaper than the circulator pump ... go to mercruiserparts online and you will see what merc charges for that black paint! Also, the crossover won't need replaced again. Some say that you gain a couple hp not turning the circulator pump, so you might gain 0.2 or 0.3 mph. If the outdrive has low water pickups only, you might run into high water pressure problems with a crossover, too. Many end up drilling bypass holes in the thermostat to help relieve some of the pressure problems, so, if/when you change the thermostat, make sure to check for any "relief holes" that may need to be re-drilled. For a stock HP500, you should have no overheating issues with the circulator pump, so gaining aditional cooling is not really a factor.

Last edited by bob_t; 02-19-2010 at 10:10 PM.
bob_t is offline  
Reply With Quote
Old 02-19-2010, 09:55 PM
  #9
VIP Member
Trade Score: (1)
 
Smitty's Avatar
 
Join Date: Apr 2001
Location: Hawthorn Woods IL
My Boats: 2000 Baja 36 Outlaw
Posts: 4,186
Default

Best to find a certified Merc tech and have him check it out for you.

My question is, if the pumps were removed, what other things have been modified on the motors??


Get it checked out before buying.
__________________
Want your ECU tuned right?? Call Mark at Precision www.pmefi.com
Smitty is offline  
Reply With Quote
Old 02-22-2010, 01:14 PM
  #10
Registered
 
Join Date: Jan 2006
Posts: 58
Default

i have a pair of hp-500's with cross overs and have never had any issues. i run a 160 thermostat with two 1/8 holes drilled in flat area. water temp is a solid 150 when engines are at operating temp.
500hps is offline  
Reply With Quote
Reply



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



All times are GMT -5. The time now is 01:55 PM.


Copyright 2011 OffShoreOnly. All rights reserved.