Trojan Boat Forum

Hi Larry,

The plug that you're showing in the manifold is in an intake runner and is definitely not a water passage. In the picture of a small block Chrysler below, you can see one hose coming from the pump and the other returning to the intake where you have a sending unit.

Since your circulation pump has two plugs in it, you may be able to get circulation between them but I'm not sure. Possibly someone who is more familiar with the Chrysler pump can shed some light on the subject.

I think the top sensor is for over heat warning. I could eliminate or put a brass T in so it would sense xirculating water temp. According to the vehicle diagram the manifold ishould be output and the pump should be return. That said seems the outgoing water flow should be sensed per above. IMO

Thoughts

any experts on 318 water pump ports for use to a water heater.

ok have a ? why can't the line running from the Thermostat housing be cut and used ? Run from it to heater then back ?

IMO the water in the housing is a mixture of hot water coming up past the thermostat and is mixed in the top of the housing with raw water directly from the Raw water pump. The engine circulation water pump is just that circulates water and replaces water going past thermostat with raw water as needed, at least I think that is the way it works, ergo any water going out of thermostate will be much cooler than water in the engine. I am thinking the overheating warning sensor is sticking into the water jacket of the intake sampling water temp. I do not see any reason if fitted into a T close to the manifold it could sense the water temp flowing out and through the water heater. Seems right there the water would be the same?

I'm not a mopar guy but it looks to me as the lines coming from the top of the housing are the hot water leaving the engine going to the manifolds for exit . Just add heater in to that loop...water will leave housing go to heater then back to manifold and out....Right ? no need to use from inside the engine and then return it to engine since you're not running in salt water or an heat exchanger....

Hi Alex

That was my first thought however Paul convinced me it should be an internal loop. I am thinking the exit water to the exhaust manifolds from the thermostat housng will not be hot enough as excess raw water from Raw Water pump mixes in the t state housing above the thermostat. The thermostat is the valve to hold water in the engine at 142 degree. But I am not sure of it. Raw water flows both directions. I think the exhaust manifolds should be about 100 degree so water going through there must be cooler than that.

I have a diagram of a truck heater system for 318, (course is closed system) and the water runs out of the intake and back to the water pump. Looks to come out of manifold where the sensors are. Looking at all possible solutions.

OK Larry, let me see if I can clarify. If you look at your raw water pump, you'll see that the hose runs from there to a T fitting. From there the water can take two different paths. The first is into the engine (bottom of circulation pump) however if the thermostat is closed and no water is coming out thru it, that means that no extra water has to be pumped into the engine to replace it. That being said, the water coming from the raw water pump (cold water)will take the second path which runs to the top of the thermostat housing then splits and goes out thru the exhaust. When the thermostat opens (at 142° or so) the hot water mixes with cold at in the thermostat housing and goes out the exhaust. Now to replace this hot water that left the engine, some of the water from the raw water pump takes the first path at the T fitting end travels into the engine at the bottom of the circulation pump. This is how the engine keeps a steady temperature.

Now a bit about the circulation pump. These are centrifugal pumps which means that the impeller draws water into it's center area and forces it outwards. Since the ports are located on the outside the impeller water will be forced out thru them. That being said, water would travel from the pump to your water heater then back to the port on the intake manifold. Also, the main purpose of this pump is to constantly circulate engine water thru the engine maintaining a fairly constant temp through out. This water is always as hot as the thermostat will allow it to be. Since this water in your engine is at about 140°F is why you want to use it to transfer heat to the hot water tank and not the water on the other side of the thermostat in the top of the housing.

Hope this helps,

Got it Paul I've never seen a pure raw water cooled block (being in salt h2o my whole life) so now that makes it clear . So I see why it has to be a closed loop system.

Glad I could clear things up Alex. Boating in fresh water does have its advantages such as long manifold life in an open cooling system. I was shocked the first time that I heard the life expectancy of an open system in salt water.

Larry, don't forget to keep us posted on your project.

Paul

definetly, hot water is only one of the systems I am working on to bring the "Phoenix" back to the water.
Targeting this spring, hope to make it.

Paul wrote:Glad I could clear things up Alex. Boating in fresh water does have its advantages such as long manifold life in an open cooling system. I was shocked the first time that I heard the life expectancy of an open system in salt water.

Larry, don't forget to keep us posted on your project.

Paul

that's why I would never run one....running them in salt sucks....