Fresh Water Cooling 7.4L

[bruceb58]

Any opinions on the San Juan Engineering fresh water cooling for a 1997 Volvo 7.4L? Are there any other brands that I should consider or should I even consider fresh water cooling at all. winterization is not a consideration since I am in Los Angeles.<br /><br />Engine has around 150 hours on it.

 

[lilmandavis]

Re: Fresh Water Cooling 7.4L

freshwater is better than salt water... im in florida and nothing ruins agood day of salt water fishing like, well saltwater!

 

[paulie0735]

Re: Fresh Water Cooling 7.4L

at 150 hours your engine is still fresh and definitely worth the investment in closed cooling if your running in saltwater. we use bowman heat exchangers, google them or check on ebay.

 

[Haut Medoc]

Re: Fresh Water Cooling 7.4L

San Juan's are good units, I have one.....<br />However, if you are in L.A. I'm assuming salt water operation....<br />150 hours/9 years of salt water operation is too long to consider FWC, IMHO.....<br />Scale will clog the engine side of the exchanger, esp. from the exhaust manifolds.....<br />I would go for it when you repower, if you replace the manifolds as well.....JK

 

[bruceb58]

Re: Fresh Water Cooling 7.4L

I thought the raw water goes through the exhaust manifolds last after the heat exchanger and that the scale problem is actually the engine side of the heat exchanger that you need to worry about.<br /><br />Am I wrong here?

 

[Haut Medoc]

Re: Fresh Water Cooling 7.4L

There are different set-ups....<br />I want to say most set ups include the exhaust manifolds on the closed side of the system, (mine does).....JK

 

[bruceb58]

Re: Fresh Water Cooling 7.4L

Most of the FWC systems I have been looking at are half systems where the exhaust is still cooled by raw water.<br /> <br />I am probably going to stick with that type.

 

[alan454]

Re: Fresh Water Cooling 7.4L

I installed a full Cool Craft system in my 7.4L merc. I would absolutely recommend a FWC system for any engine is used in salt water. Full systems include the exhaust manifolds, half systems only include the block. The full system is only marginally more expensive than the half system and just as easy to install - only 4 more hoses.

 

[bruceb58]

Re: Fresh Water Cooling 7.4L

Is Cool Craft still in business? Looks like the website is no longer working?<br /><br />How long ago did you buy it?

 

[tommays]

Re: Fresh Water Cooling 7.4L

Your a GOOD 8 years past the recomened time of 1 year the tubes are tiny and will clog with scale VERY easy <br /><br /><br />tommays

 

[paulie0735]

Re: Fresh Water Cooling 7.4L

Haut, 150/9 years = 16.6 hours per year........man you need to get out more!!

 

[Haut Medoc]

Re: Fresh Water Cooling 7.4L

What's your point? A nine year old engine with 150 hours on it is not a candidate for a FWC conversion no matter how ya slice it....<br />It wouldn't even be a candidate if it had never seen salt water.... Scale is scale & it ain't going away in a closed system....JK

 

[bruceb58]

Re: Fresh Water Cooling 7.4L

I agree with you guys and I am not going for the FWC.<br /><br />This is a 97 engine in a 98 boat which was not purchased until 99.

 

[alan454]

Re: Fresh Water Cooling 7.4L

bruceb - I can't find it either. I guess they are out of business. I purchased it about 4-5 years ago. The cool-craft guy said they were the OEM manufacturer for Merc? <br /><br />Does anybody know what happened to cool-craft?<br /><br />I was worried about converting a RWC system to a FWC system also on an older boat also, so much so that I installed a large (temporary)filter/strainer on the return line. I did get scale and rust particles averging a bit less than 1/4" for while but never any large pieces. What I did capture in the strainer could be crushed easily in my fingers. It turns out that antifreeze is mildly acidic and it looks like it eventually decomposes the rust/scale. However, "your milage may vary" as they say - good luck!<br /><br />One more thing - I used new intake and exhaust manifolds, and the cool-craft unit eliminated the tstat manifold.