I have a '61 955H that I rarely use in the winter. I would like to use it more but have a hard time starting it below 25*. I think it has a D330T engine. What size block heater do I need and where is the best spot to put it??
http://www.fivestarmanufacturing.com/Guides here is one catalog. They didn't list the 330 but you could compare the other cat heaters to your engine and see if any of the others would work in a spot you have access. Some were only 400 watts which would help, but I'd use a 1,500 watt radiator hose or tank heater rather than go to the trouble of a 400W block heater. I'd prefer the blockheater, but not that low wattage. Or maybe one of the old Cat experts will recover from heat stroke and suggest a better option?
A circulating heater would work good either 1000 watt or 1500. You can put one line in by the thermostat housing , there is a pipe thread plug there. The other line should come out of the middle of the block if you can find a coolant plug on the oil cooler or block in that area.
Do the circulating heaters have a pump in them that circulates the coolant?? If so, is the 1500w rating just for the heater or is it the TOTAL draw?
No, they have to be mounted carefully so that the warmer coolant rises and circulates by convection. There are pump models but they're typically found on backup generators, not the cheapo tank type ones that you see commonly.