Billswan's 16/1 Metro

[bschwartz]

I'm currently using a fattywagon type line heater wrapped around my injection line to help heat the WVO.  If I understand it correctly, they draw about around 8 amps at 12v (listed as a 100 watt heater).
It gets my line pretty toasty.
I couldn't tell you how hot the line gets, but my thinking is, the hotter the better.
My fuel used to sit in restaurant fryers at over 300 degrees F, so I can't imagine I'm overheating it in the line.

[rcavictim]

IME it isn't the injector line you need to heat, it is the injector body itself.  If you heat the oil in the line if it hits a cool injector body (maybe 170F) it will turn cold and thick again from the relatively cool temperature of the injector body.  You want to get that injector body up to 300-350F.  To do this you don't need 3 feet of heat rope, you need 6 inches and about 100-120 watts.  After the engine is stable under load you can back off the injector heat a bit.  I start my tiny JD175A on diesel and get the engine up to near operating temperature, then I turn on the injector heat at 100 watts and minutes later introduce the fuel changeover to heavy oil. After a while at running temp I back the injector heat down to about 60 watts and leave it there.  I turn off the heater and switch to diesel again to do a flushout cooldown shutdown.  If you shut down with a hot injector it may stick shut.

I have not tried WMO yet but have successfully used some thick as molasses oil I acquired that burns really clean by this method.