1989 4.3LX new water heater with heat exchanger

[HPLou]

2 x 4.3Lx 1989
I just bought a new Atwood Water Heater (replacement) with Heat Exchanger. The present installation only supply Hot Water at the dock with 120V. I want to modify the installation so that I can have Hot water at the dock and cruising when the engines are running.
I think I have 2 posible installations;
Before the Thermostat on the Thermostat Housing on a Pipe Plug or On the Exhaust Manifold.
I am I right ?
Witch installation is the most comment?
Any drawings available to help me visualize and make the installation ?
I have the Merc Service Manual #7 and did not find anything related to this.
Thank You

 

[alldodge]

Re: 1989 4.3LX new water heater with heat exchanger

They all work pretty much the same way. Water comes from the thermostat housing to the WH, then returns back to the large hose going into the engines water pump. Look at the thread below which DonS has a manual section for a 5.7

http://forums.iboats.com/mercruiser...umb-water-heater-mercruiser-5-7-a-491306.html

 

[Bondo]

Re: 1989 4.3LX new water heater with heat exchanger

2 x 4.3Lx 1989
I just bought a new Atwood Water Heater (replacement) with Heat Exchanger. The present installation only supply Hot Water at the dock with 120V. I want to modify the installation so that I can have Hot water at the dock and cruising when the engines are running.
I think I have 2 posible installations;
Before the Thermostat on the Thermostat Housing on a Pipe Plug or On the Exhaust Manifold.
I am I right ?
Witch installation is the most comment?
Any drawings available to help me visualize and make the installation ?
I have the Merc Service Manual #7 and did not find anything related to this.
Thank You

Ayuh,.... Generally speakin', there should be a 1/2" pipe plug in the intake manifold, before the t-stat housin' to feed the hot water, 'n a 1/2" pipe plug in the circulatin' water pump for the return water,...

 

[Fun Times]

Re: 1989 4.3LX new water heater with heat exchanger

iboats member agallant80 posted a good photo not long ago that should help give you a visual of where to tap into. http://forums.iboats.com/attachment.php?attachmentid=224841&d=1393886868

 

[HPLou]

Re: 1989 4.3LX new water heater with heat exchanger

Thanks Guys
I have now a very good idea and have to find those two Pipe Plug on my 4.3 lx 1989.
Fun Times, the photo link, is it on a 4.3l or 5.7l ?
thank you

 

[Bondo]

Re: 1989 4.3LX new water heater with heat exchanger

Thanks Guys
I have now a very good idea and have to find those two Pipe Plug on my 4.3 lx 1989.
Fun Times, the photo link, is it on a 4.3l or 5.7l ?
thank you

Ayuh,.... It appears to be a 4.3l, Vortec, but yer's is somewhat similar, 'n yer plugs will be close to those points,...

The port on the circulatin' water pump might be on the top, bottom, or side,...

 

[HPLou]

Re: 1989 4.3LX new water heater with heat exchanger

thanks Bondo for the precision.