First off, let me thank you for a great web site with lots of practical information. Over the last few months I have taken the liberty to read a large portion of the information i the SurvivalBlog archives. I have, I believe, an untouched tidbit: Many folks live in areas susceptible to frost. Some of us live in areas susceptible to sub-zero temperatures. Cold starting a vehicle, either gas or diesel can become problematic at best, or almost impossible when the thermometer dips into the minus figures.
Having lived in an area that sees the minus 70s (without a wind chill factor) and having to start vehicles or airplanes (or the snowmobile for that matter) without the advantage of oil pan heaters, head bolt heaters, battery blankets and all the other things that need a electricity to pre-heat the engine I revert back to the old [propane] weed burner trick. I first used it while wintering in the Wrangle Mountains to pre-heat the Supercub and then used this method for pre-heating while living off grid for a number of years in the Interior of Alaska.
The tools are simple. A propane weed burner, propane tank, several sections of stovepipe and a 90 degree elbow. A blanket or tarp will speed up the process a mite. The object is to create a forced air furnace of sorts by sticking the weed burner just inside the straight section of stovepipe and point the elbow up towards the oil pan. You need to have a stovepipe with a larger diameter than the weed burner end, a couple inches will do. If you get too small a diameter stovepipe, the stovepipe simply becomes a long flamethrower and overheating will result!
Once you ignite the weed burner and stick it into the end of the stovepipe, the force of the flame pulls outside air into the stovepipe, heats it, and sends it down the line to the engine compartment. It is pretty simple to adjust the heat and distance to the the motor to avoid melting anything you do not want melted and to avoid boiling the oil.
A couple of finer points that I’ve learned over the years:
Propane fails to reach vapor state at around minus forty. The weed burner will slowly turn to not much more than a candle flame. I simply set the tank slightly forward of the hottest part of the stovepipe and off to the side enough to catch some radiant heat. You must monitor this carefully as it is quite possible to get so much heat to the propane tank that the LP begins to expand which creates a larger flame, more expansion and it will experience a not so pretty ending. (Unless you hate the rig and have good insurance)
If you have an oil pan heater on the bottom of the pan you need to keep the heat to a minimum so as not to damage the oil pan heater. Smaller cars (like my wife’s Subaru) need smaller stovepipe and hence a smaller weed burner (to facilitate airflow around the weed burner tip and into the stovepipe) I can pre-heat my old Toyota at minus fifty in less that twenty minutes with this method. My crew cab diesel pickup takes twice that long.
By throwing a blanket or tarp over the hood so that it drapes to the ground, you will find that not only has the engine warmed up but you have also heated the front wheel bearings, tranny, battery and coolant. When I have a tarp draped over the front, I simply feed the stovepipe under from behind the front tires.
While it is much easier to have the electric doo-dads in place, there comes a time when you simply do not have an extension cord long enough to plug the things in.
As a side note, I have, in the past, pre-heated with everything from a bucket of coals to the MSR Whisperlite [backpacking stove]. While it may seem like a royal pain, it is actually quite simple and far easier than draining the oil and coolant and pulling the battery every night to leave them near the woodstove. I hope this helps someone to get up and get going some frigid day in the future. My best, – Scotty (aka “Coldfingers”), Fairbanks, Alaska