Berkeley jet and FWC, heat exchanger, ect. Advise needed.

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Hello. Looking for advise on FWC on a Baja 190 Jet boat.

I just got a Baja Jet Boat, from around 1978 i think. It?s my first boat ever!

Engine: Mercruiser 7.4, 1997 Model nr: 474B110KS
MERCRUISER TB5, W/PS, TWOPCEX, WORO, GEN6 7.4L BRAVO

The engine has a total of 150 hrs. in fresh water (Basel in Germany)

I can only run the boat in Salt water where i live, and considering the reletively low hours on the engine, also considering that the boat never was in salt water, i think it?s worth to try and protect the engine with a FWC.

I?m looking at a FWC full-system from seakamp, model nr.: SK4823

I have read various subjects around preshure level and needed modifications on Berkeley Jet, with and withour thermostat, pressure problems, ect.


Any advice on the mentioned FWC system, together with the Berkeley jet ?
Anyone could tell me my engine performance (HP), based on the model nr. (engine is carburated, NOT a MFI) ?



Thanks
/Jesper

 

[Bondo]

Anyone could tell me my engine performance (HP),

Ayuh,.... Welcome Aboard,.... Dead stock, 'bout 330 hp,.....

I guess you could run a heat exchanger, but you'll need to limit the water pressure to 'bout 15 psi,....

 

[Scott Danforth]

welcome aboard.

the bravo and alpha raw water pumps are capable of 20 psi.

most jet boat motors do not have a circulation pump, so if you plan on running a heat exchanger, I would keep it. Also, if you have the complete Bravo motor, you should also have the bravo seawater pump. I would use a separate water pickup and strainer for the seawater pump and run that into the HX. then you dont need to worry about dropping the pressure off the pump pickup.

this adds a bit more weight than normal jet boat installations, however its your boat, and you are already adding #70 for the HX.

if you are running open exhaust headers like most jet boats, then your heat exchanger only needs to be a half system and not a full system. headers generally have too much restriction to run them in a full system.

 

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@bondo: Thanks
scott Danforth: Does Berkeley 12JF Jet drive have a mecanical waterpump for the cooling system to do the same job, as the impeller in a Bravo stern drive?

No open exhausts, there is a pic of engine + boat attached in the post.

Excause me for beeing almost totally blank, but HX means "heat exchanger" i guess.

Thanks
/Jesper

 

[Scott Danforth]

usually the jet drives simply take pressure after the impeller wheel. there is no mechanical pump. simply pressure from the jet is diverted to the block and exits the exhaust. generally jet boats are go really fast and run as light as posible, so things like heat exchangers, circulation pumps, thermostat housings, etc. are all removed.

yes, HX = Heat Exchanger.

 

[Scott Danforth]

here is an exploded view of your 12JF http://www.americanturbine.com/diagrams/jets/OEM_berk12jf_diagram.htm