Where to grab coolant from engine

[ToddT]

I'm hooking up a buddy's '02 7.3 PSD this weekend and need some advice on where to grab the coolant. I know most tap into the heater core loop. Someone here said there are some ports on the engine that work as well.

I'm currently using a spare 3/8npt port on the water pump but its in a dead space immediately below the thermostat. As a result, when the thermstat is closed it doesn't have that much flow.

What other ports have good flow rates?

If not another port, I'll grab coolant from the heater core loop. Right now I'm thinking of running all the coolant from the engine, through the WVO heating loop and on to the heater core.

Regardless of where I grab the coolant, I'll upsize to a 3/4" heater hose to compensate for the greater distance to push the coolant.

Thanks in advance.

Todd

[BlueMule]

Todd
I get mine from the port on the rear of the drivers side head. I have an OBS truck so I can reach it from above or below, but on a SD I think you'd have to get to it from below. It is slightly higher and to the rear of the exhaust manifold and is a 1/2 npt plug with a 3/8 recessed square drive that takes a 3/8 extension to remove.

Both heads are the same so if you look at where the heater gets its supply from on the pass side and then visualize it turned 180º you will know where to look for the plug on the drivers side.

[ToddT]

Thanks for the reply. I was going to ask if it had good flow/velocity but if it is feeding the heater core, it must be good. It didn't dawn on me that the coolant inside the engine had that much flow at all times.

I really like that it is a 1/2" npt port rather than a 3/8"... much better for feeding that 3/4" hose.

Anybody else try to access this port on a SD/PSD?

Todd

[ToddT]

Yesterday I helped a buddy install a WVO system in his PSD. We got the coolant from the driver's side head port mentioned in this thread. We used a tee to introduce the WVO system coolant to the line from the heater core back to the engine. My buddy just called to say the system isn't getting warm. Could the flow from the heater core be greater than the flow coming from the veggie system, effectively stopping the veggie coolant flow?

Anybody have any problems routing all the coolant from the engine through the WVO heating loop and then on to the heater core?

Todd

[BlueMule]

I know you mentioned using 3/4 hose for the HIH. What size is the interior tubing? What are the temperatures you are seeing on the veggie and whats the water temp? Where are you returning the water back to the block? You do know that the water flows from the heater core and returns to the hose that goes back to the water pump. A few quik calculations shows me that the area if the ID of a 3/4 in hose (.4417) minus the OD of a 3/8 tubing (.1104) still leaves (.3313) for coolant flow and that's more than a 5/8 (.3067) hose can flow.


I come off the head with a 1/2 nipple into a tee. From the tee I have a 5/8 barb that goes up to the tee where my 3/4 x 3/8 HIH starts and a temperature sensor. Where the veggie line exits the tee I have another temp sensor. With a 203º and no fan I get 195º water from the head and between 165º and 180º oil just before it enters the pollak valve.

[ToddT]

Thanks for the reply, Blue Mule.

As one who deals with process flow rates and such, I'm well aware of surface area of hoses. I still can't understand Greasel and thers using 1/2" for coolant. Its amazing the difference each 1/8" increase in hose/pipe size makes.

We up-sized to a 3/4" heater hose for the WVO coolant heat loop... no HIH. We fabricated a HOH wrapped with insulation.

I planned to use 1/2" alum. tubing for fuel supply and return plus 3/4" copper tubing for coolant supply and return, wrapped with pipe insulation. The only place we could create a straight run with this was from in front of the fuel tank to the 6-port fuel selector. Its about five feet so its worthwhile. Unfortunately, we ran out of time during this installation. My friend was in from out of state and we had very limited time.

My buddy called from home today and said he is getting some pretty good heat now. We also forgot to ground the brass T into which we installed a temp sending unit so his WVO temp gauge isn't working yet.

Where do you return the coolant? We added a T in the hose from the heater core back to the water pump. I wondered if the flow coming from the heater core was great enough to effectively shut down the flow returning from the WVO heating loop.

Thanks for your help.

Todd

[BlueMule]

I returned the coolant the same way you did. I put a 5/8 tee in the heater return and returned it back to the pump.

What was it like trying to get to the coolant plug on a SD head? Can you even see that far back from above?

[ToddT]

My helper installed the fitting but it wasn't too bad. I can't remember if he came in from the top or from the bottom. I'll ask him later today.

Thanks for the help, guys.

Todd