6-71 in line natural water heater with exchanger install

Folks; I am new to site but not new to engines however, I am in need of information as to where to connect both hoses that are needed to go to the exchanger on a water heater. I thought one would tap off one of the exaust mainfold small two bolt flanges which should be under pressure and around 170-180 degrees prior to entering the oil cooler. I however have no idea where to connect the other hose prior to the circulating pump to be on the suction side. any idea's. Thanks Jim

Yes; The water heater is a raritan 110 volt plus it has a exchanger, that would use hot engine coolant to also heat the domestic water as well as 110 voltage. my delema is where to connect on the engine coolant side to give me a (loop) of hot coolant that will come from the engine ,thru the water heater exchanger,then back to the engine. This is a in line 6-71 natural,heat exchanger cooled,marine. note; all connections will be on the FWC side not raw water side. thanks Jim

Thanks KIM; I understand it will take a pressure diff.to create flow,I however have (no) factory connections on the marine Detroit so I guess I will have to fab some.I thought someone out there would have installed a water heater with a exchanger on an old 6-71.I was just wondering how they plumbed a BUS HEATER on the old buses ?FYI ,the circulating coolant pump is shaft driven directly off the blower and only a 1/8"pipe drain plug n the cast pump hsg.and a really short 1 1/2" suction hose from the oil cooler. I have the DD manual for coolant flow diagram BUT no mention of a heater . Thanks again,Jim

KIm; Yes my pump is similar but has only one (small boss) at the bottom of pump 1/8" npt.for a drain. and yes again,the engine oil cooler is fwc.the tranny oil cooler is salt water cooled. If worse comes to worse I could always buy that pump on e-bay but seems to be a easy fix, none of my projects ever come out that easy! Thanks again,Jim

I worked on the old GM transit coaches and the passenger and driver's heater/defroster was plumbed FROM and TO the water pump suction pipe from the radiator. This was the COLDEST water to be had after it left the radiator.

A 12VDC "diversion" or booster pump was used for positive flow and was preceded by a pressure "modulator" (regulator) to keep pressure spikes from occurring during higher engine rpm.

The return flow was isolated from any "back flow" to the heater cores and pump with a one way check valve as these were open displacement centrifugal pumps.

I recently studied an engine heated hot water installation on a medium sized sailboat (Ranger 32) and, while it appeared to be a very clean, professional install, I have to admit, it didn't make much sense to me. But, I've never done one so what do I know?

Sorry, not of much use, I know, but you mentioned bus and I been THERE so I just had to brag about it.;~)