[oil pan 4]

I have done this before so I know it works. Last time I did it was before I joined here.

All you do is take a 1'NPT pipe coupler, weld it to a plate with a hole cut in it, making a flange then stick the highest voltage hot water heater element that you can get that isn't too long. I think I had to use a 1500 watt 120 volt heating element last time.

I have the oil pump, oil pan and the engine block all I am waiting on is the oil pump pickup to finalize oil heating element placement.

There are some requirements to selecting and placing the heating element in the oil pan.
1 it needs to be less than the width of the oil pan.
2 you need to make sure the heating element does not interfere with the oil pump or pickup.
3 the heating element needs to be below well below the minimum recommended operational oil level.
4 put the longest heating element you can fit in there.

Then once you know all those requirements are met, cut a hole in the oil pan and attach the flange. Last time I tack welded bolts to the inside of the oil pan and bolted the flange on with a gasket. This time I am just going to weld it all.

The heating element needs to have a lot of surface area. Because you don't want to run it anywhere near its rated wattage. 300 to 400 watts should be plenty. You don't want to install a small 300 or 400 watt element because they get way too hot. As the engine runs junk settles out of the oil and lands on the heating element if the heating element is ran at full power this stuff gets cooked on to the heating element, will build up layer after layer each time you use the heater and will eventually over heat and burn out the heating element.