for drivability and mileage reasons , going to pair up carb base hot (engine) water heat with the Dutra Duals on the D-150.

here is a sketch of what I think the hose routing needs to be.

http://www.flickr.com/photos/13718356@N ... 997331963/

basically,
1 line from the motor to the carb hot water box
1 line from the carb hot water box to the cab heater core, also adding AC, so I think I need to a vacuum actuated hot water shut off switch,, guess it goes on the side taking hot water to the heater core
1 line from the heater core back to the motor
1 line making the cross over connection from the carb hot water box back to the motor, for when the vacuum shut off is closed.

question(s)
1, is this the correct routing for the hoses?
2, is it OK to run water to the carb hot water box continuously
3, for the line making the cross over connection, do I need to make that line a smaller diameter than the others, so water will push on to the heater core when I want cab heat or temperature modulated AC?


thanks
DT

I don’t have air conditioning, so no shunt or valve isolating heater core, but the loop is as you describe; water pump to carburetor, carburetor to heater core, and back to return at water pump. I run a 195* thermostat for two reasons, firstly to keep the intake warm, and secondly to keep me warm when top is down during cool weather. Top down weather for me is dry, 35 degrees and up.

This set-up has worked very well, completely eliminated icing and cold weather drivability problems in conjunction with an electric choke equipped Holley 390 utilizing a thermistor to better control early choke pull-off.

I can now start the engine at any temperature, lowest to date 15*, let the engine warm for ten to fifteen seconds, and then drive off with no stumbling. My choke is slow to make initial pull-off at start that I suspect is due to low vacuum at idle.

Previous to heated manifold and thermistor modifications the car was a stumbling pig below 60 degrees from a cold start, and bellow 40* and humid a stumbling fuel swilling pig all the time due to icing.
Works for me.
Perhaps you can use two valves that operate in tandem, one stopping flow to heater core, the other opening a shunt so coolant flow is not compromised to manifold when the air conditioning is on.

Bill

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67' Dart GT Convertible; the old Chrysler Corp.
82' LeBaron Convertible; the new Chrysler Corp
07' 300 C AWD; Now by Fiat, the old new Chrysler LLC

As pictured, I think coolant would take the easier path and bypass the heater core.

Either a restriction in the bypass hose or 2 valves.

When heater valve is open, bypass hose is closed and vice-versa.

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Ed
64 Valiant 225 / 904 / 42:1 manual steering / 9" drum brakes

Which hose is the ruturn, the top or bottom one from the water pump?

Sam

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Good question Sam, I don’t recall.

A brief pause in typing while I look at which tap feeds the manifold, a short intermission if you will dear reader…

I’m back. The hose exiting the head feeds manifold as this would be hottest water, and first to warm before thermostat opens. Than from manifold to heater core, and return line form core to water pump nipple.

I would use two valves to control flow if a shunt is employed as one would not want any loss in heater output from shunt bleed by…

_________________
67' Dart GT Convertible; the old Chrysler Corp.
82' LeBaron Convertible; the new Chrysler Corp
07' 300 C AWD; Now by Fiat, the old new Chrysler LLC

thanks, I'll look around for a second vacuum operated shut off, going to be interesting to come up with the way to actuate one open and one closed.

1. In my setup, I run hot water to the heater core first and then return the full flow through my intake heater.
2. I run this all summer and do not have a vapor lock or poor hot idle issues.
3. If you are getting too much heat so that you have poor hot idle or vapor lock, I would first add more insulation between the carb and intake manifold before I would try bypassing some flow.

Be sure to watch Down the Gasoline Trail (1935).

what if instead of adding a shunt in the hoses that run to heater core to get hot water to the carb base, you used the existing water pump by-pass flow to flow heat the carb base,,,

here is a sketch of the routing

http://www.flickr.com/photos/13718356@N ... 182420991/

normally the bypass feeds water from the head to the water pump, instead of doing that directly, what if the water ran from the head to the hot spot at the carb base, then to the water pump? ? It means that as soon as soon as water flows, water from the head (the warmest water available) is hitting the bottom of the intake.

here is mock up on a short block.

http://www.flickr.com/photos/13718356@N ... 182329899/

Hoses on the left would run to the heater core as normal.
The brass fitting and hose on the right side show the proposed water flow...out the brass fitting to the carb hot spot and back to the 90 degree hose on the water pump..

The by-pass pipe on the lower section of the thermo area would be removed and plugged. The water to the carb heat hot spot would flow from one of the sensor bosses on the top side of the head. A straight brass fitting is shown, but a 90 would be required. Return water from the carb hot spot would flow back to the pump via the 90 degree silicon hose like the one shown.

looks like a workable solution to me,, some water always goes through the by pass,, difference here is the water is diverted through the carb hot spot,, the flow to the heater core is not affected.

regards
DT

That looks like a great way to do it!

CJ

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Part of Tyrde-Browne Racing

Flow to manifold, and back introduces several restrictions that the pump & coolant see as a much longer path. When designing piping systems, or air moving duct work every fitting, length of pipe, and bend introduces restriction. 90* bends more restrictive than 45* bends, 45*fittings more restrictive than straight runs etc. , and all are additive. So as twists & turns add up, pump sees a much longer run than actual distance fluid travels. I’m not making this too clear, and neither is my head out of the fog this morning as well.

I would be concerned that introducing additional restriction to coolant flow between pump & head may cause reduced primary cooling flow. Reduced flow to the heater core and carb base won’t interfere with cooling engine, however I should think keeping factory routing would be beneficial to convection cooling after shutdown, and overall dynamics Chrysler intended when designed.

2 cents

_________________
67' Dart GT Convertible; the old Chrysler Corp.
82' LeBaron Convertible; the new Chrysler Corp
07' 300 C AWD; Now by Fiat, the old new Chrysler LLC