Close circuit Cooling system for Mercruiser 4.3 MPI 2010 Vintage

[federicob162]

I own a Maxum 2000 sc bota equipped with a Mercruiser 4.3 MPI, 2010 Vintage to which I would like to incorporate a close circuit cooling system. Will appreciate help in selecting the right the kit to buy. Thanks - Federico

 

[Scott Danforth]

If the motor has EVER run in salt water prior, no use putting a cooler on it now, the salt has already permeated the cast iron of the block and heads

If your motor has low fresh-water only hours, you can put a cooler on it, however you will need to flush out your block to get rid of all the sediment that is in there (and trust me, there is about at least a half pound of sand, rocks, and gravel sitting in your block currently.

you can look at San Juan Engineering for aftermarket kits, however after 7 years, I question if it would be of any value of benefit to your motor

 

[tpenfield]

SeaKamp and San Juan Engineering (SJE) are the more popular aftermarket kits. See which brand has the best offering for your engine.

Scott's point is well taken . . . prior fresh water use would be fine. Salt . . . not so much.

I put SJE kits on my engines that were going from purely fresh water use to salt water use.

 

[Bondo]

Ayuh,..... Welcome Aboard,..... Ditto the Don't Do It,... if it's been run in the brine,....

Even if ran in freshwater, a serious flushin' of the block oughta be done, before the system is installed,....
At 6 years old, there's no doubt sediments in there,....

 

[federicob162]

Thank you all for your advise, and apologies for the late acknowledgement. My boat has always run in soft (no hardness) fresh water and has 260 hours of use. This engine is a replacement of another Mercruiser MPI, that suffered a cracked block because of obstruction with a polyethylene bag and subsequent sudden cooling.
This is what I'm trying to avoid by using a close cooling system.
In the environment where I do my boating the Mercruisers 4.3 have a reputation of failing because of block breakage. The new mechanic that services my boat says that this happens because most of them have open cooling systems that get clogged in the same way my former motor had.