Ok men, finally something to do with a CJ . 3 days ago I installed a circulating engine heater. This is a 1500 watt model that also comes in 750 and 1000 watts. The brand is zerostart from Temro. I got this at O'Reillys on a price match ( regular $89) for $49 to match another brand.
Install was straight forward, using the water jacket drain plug (3/8"npt) on the passenger side of my 304, and then tapping into the heater 5/8" return line. All antifreeze needs to be drained for this install.
Drain plug location.
In the above picture you can see the 5/8" hose is close to the starter, I split a piece of 3/4" hose (3" long) and placed it over the 5/8 and secured it with a hose clamp. I also used the 3/4" hose around the base of the heater/pump with a clamp to prevent any wear on the aluminum pump housing. The hose is pretty stiff so exact location is difficult.
The kit comes with the block fitting , clamps, a power cord that's too short to reach the grill on and vehicle, and the "Y" for the heater hose. You would need to buy about 2' of 5/8" hose for the install.
I plugged the heater in last night prior to my trip to work this morning. Temps over night were 8* F. I set up a 15 amp outdoor timer to run the heater from 2 to 6am. I am really pleased with the results. The Jeep warmed up 2X as fast, and got heat from the heater right away, not a lot of heat, but it wasn't 8* air either.
We also got 3/4" of snow overnight. This morning the snow was melting on the hood.
So this am I hit the gas pedal to set the choke, the jeep cranked but wouldn't start. WTF, so I pumped the gas a couple times, still no start, cranked over really fast though. I then held the gas pedal to the floor ( flooded engine routine ) the jeep fired right up. The Jeep fires right up using the same set the choke routine in 90* weather. It also only requires a lite application of the pedal with a warm start. So there appears to be a learning curve.
Time for pics. Sorry about the quality, the iPhone was receiving too much hight from the FD Thermal Imaging camera . On the camera screen the lighter the object, the greater the heat. The camera also shows temperature where the crosshairs are pointed. Don't be thinking about running out and picking up one of these cameras, they run $20,000. This is not a typo
The temperature in the fire garage is 68*, the heater has been plugged in for 2 hours. The first pic shows a 100' extension cord, and the hood up on the Jeep. Extension cord snowed 80*
Both heater hoses showed 173* and 123* at the water pump housing.
Intake manifold from the drivers side.
And the drivers side engine block just under the exhaust manifold.
I'm going to recheck temps in a couple hours.