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Hagman
04-15-2011, 12:27 AM
I got a heater for my 86 comp . The instructions that came with the kit didn’t say where to plumb the hoses at the engine . I looked at friends Mustang and Ford used the two outlets off the water pump. I installed my heater the same way but I don’t get any heat until the engine is up above 1800 RPM. You guys know a better way to plumb the heat lines?

cadunkle
04-15-2011, 08:24 AM
Ford does not use the two outlets on the water pump for the heater. One is for the intake bypass, the other is return from the heater. The water pump is pulling water from both of these fittings.

Your heater output should be coming from the intake manifold before the thermostat. This is where the water will be hottest and controlled to the temp of your thermostat. If you already have it set up this way,then it should work. Remove the return hose, plug the return port on the water pump, and check at idle and off idle, see what the flow looks like. Be careful if you do this in the water.

beast 496
04-15-2011, 08:42 AM
I install alot of heaters, remember you have a non pressurized system, If you hook up like Cadunkle states it will work fine for driving but at idle the water flow and heat output will be limited due to low water flow.
If you want more flow and higher low rpm heat, the output or + pressure hose is attached to the intake manifold. The suction or - pressure hose can be spliced into the water intake prior to raw water pump hose with a Y connector. You will still be pumping raw cool lake water into and out of the engine, but also be circulating hot water along with it. The down side of this is only slightly longer warm up time for complete engine warm up. Maybe 8 minutes verses 5 minutes. But you will have great heat even at idle speeds.
Good luck Al

stinky_1
04-18-2011, 10:11 AM
so, in this example we are counting on the raw water pick up to actually pull the water through the heater? This sounds like a great idea! I always was looking at it the other way thinking I wanted to have my water pump PUSH warm water into the heater, and then let it just drain out close to the exhaust manifold to go back into the lake.

That way would require the high RPM though to be able to push that water through there. otherwise it will just bypass the system entirely.

I like the raw water pump creating suction and then the small bit of pressure from the water pump at idle speed is enough to circulate the warm water through there! Learned something new today. Thanks beast!:D

Hagman
04-19-2011, 12:11 AM
Beast
I’ve been thinking all along that there had to be away to make the heater work rite. The guys at the boat shop here suggested I buy a elect. pump to put in the line at $160 bucks there had to be away other than that. I changed the plumbing this weekend and went for a test ride on Sunday. Holly shhhhh dose the heat come out , even at idle.. Thank you for the tip.

beast 496
04-19-2011, 08:30 AM
I am glad you are happy with it. We have been installing heaters in boats for close to 25 years now. Your guys at the shop were on the right track also with an electric pump, but we usually do not need to go that far. Some application where we have two different heat exchangers for cruisers we will add a boost pump. Good job on the new mod. Al