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RedDog
11-20-2007, 03:57 PM
1998 Merc 502 MPI Mag with serpentine belt

I may have to replace my circulation pump in the Spring - I think it may be leaking (but won't know for sure until I fire in up again in the Spring and can look closer - I have a drip coming from somewhere near the front of the motor). If replacement is needed, maybe a switch to a crossover kit would be the best approach instead of buying a new pump (around $165). Here are a couple of kits that I think would work:

Stainless Marine @ $333 - http://www.stainlessmarine.com/thermostat6.html
Hardin Marine @ $290 - http://www.cpperformance.com/detail.aspx?ID=7588

The Hardin Marine seems to be more complete and costs less. The Stainless Marine looks better (and I think a set of Stainless Marine manifolds and risers are somewhere in my future).

With either of those kits, is there a challenge because of the current serpentine belt? Do I just replace the current belt with a shorter one?
Any other issues on a basically stock motor - I have read that the thermostat must be drilled.

gcarter
11-20-2007, 04:41 PM
You may very well need a new idler/tensioner arrangement. But someone around here will have done it.

Pismo
11-20-2007, 05:04 PM
According to Teague, if you like/believe/listen to him, it's not a good idea because the engine runs much cooler(I don't know why) with a crossover and should have the ECM re-calibrated to reflect this. I would think there must be an easy way to get the temp back up to 150+ tho to deal with this. There was a Teague letter in Powerboat talking about this a while ago.

DonziFreak
11-20-2007, 05:29 PM
i run the stainless marine crossovers and manifolds on the crusader 350 we have, they work awsome, but i'm not to sure about the computer situation....i have heard about it before, and if i remember correctly, i think there was a thread here a while back that went into detail on that...

CHACHI
11-20-2007, 06:53 PM
Tim, if the circulation pump has gone bad there will be rust around the weep hole at the bottom of the pump.
Ken

RedDog
11-21-2007, 06:51 AM
Tim, if the circulation pump has gone bad there will be rust around the weep hole at the bottom of the pump.
Ken

Thanks for the tip!

VetteLT193
11-21-2007, 07:38 AM
The easiest way to do this is to get the Keith Eickert setup with the dummy pulley: http://www.keitheickert.com/products/Cooling/crossovers-efi.htm

VetteLT193
11-21-2007, 07:40 AM
Here's another link, from Hardin. Didn't realize they are the ones that made it...

http://www.hardin-marine.com/detail.aspx?ID=1605

Not cheap, but at least it's easy and a permanent replacement

BigGrizzly
11-21-2007, 08:19 AM
Then you still have the cooling question. I prefer the circ pump for evener heat distribution. However I have closed cooled all my boats now for the same reason and some others too,

gcarter
11-21-2007, 08:31 AM
Here's yet another option (LOOK AT THE BOTTOM OF THE PAGE) although I wouldn't reccomend it for salt water unless it's closed cooling.
Also the price is similar.
http://meziere.com/2007_catalog/13.pdf

VetteLT193
11-21-2007, 08:42 AM
Here's yet another option (LOOK AT THE BOTTOM OF THE PAGE) although I wouldn't reccomend it for salt water unless it's closed cooling.
Also the price is similar.
http://meziere.com/2007_catalog/13.pdf

I don't think it will work with the Merc setup. The belt tensioner is usually mounted higher on a regular chevy setup. the merc setup it's low and off to the side. it looks like it relies on a water pump pulley, or some pulley in the center.

gcarter
11-21-2007, 09:11 AM
I don't think it will work with the Merc setup. The belt tensioner is usually mounted higher on a regular chevy setup. the merc setup it's low and off to the side. it looks like it relies on a water pump pulley, or some pulley in the center.
It's an electric pump that pumps a continuous 55 GPM. It has a idler pulley built around the motor. I was thinking it might solve some of the potential problems listed above.

RedDog
11-21-2007, 10:08 AM
It's an electric pump that pumps a continuous 55 GPM. It has a idler pulley built around the motor. I was thinking it might solve some of the potential problems listed above.

A chrome pump would look pretty good!

http://wizbangimages.com/image/60.jpeg

Air 22
11-21-2007, 11:03 AM
Then you still have the cooling question. I prefer the circ pump for evener heat distribution. However I have closed cooled all my boats now for the same reason and some others too,

I'm with Griz...Steam pockets can occur without even water distribution/pressure...not good for the engine..I tried what you are wanting to do w an old 454 385 magnum...I just removed the circ pump..used the Stainless Marine crossover and T-Stat housing Kit(http://www.cpperformance.com/detail.aspx?ID=2900) ..no Drilling req..and went from 4 belts to 3...but saw no real gains in performance on a stock motor. The circulation pump really is important for even water distribution...I'm not an engine builder but have had a little experience trying this stuff...and my mech recommended NOT doing it on my new 502. The leak u have is prob an bad water pump seal(gasket) and or pump. ...Just an opinion for some experience:smash:....many others have far more knowlegde...hope this helps...:wink: