WVO Diesel Conversion: 12 Volt Stainless Steel Resistance Wire Injector Line Heater

Use caution with these heaters. They get hot. Always use a fuse and do not mount them where they can contact anything that can burn.

Parts and tools:
1. High temp tape $13 McMasterCarr # 7643A481
2. Fiberglass rope 32 cents/ft McMasterCarr # 8818K43
3. Uninsulated butt connectors $5 for 10 McMasterCarr 7934K2
4. .035 Stainless steel welding wire from the home store or welding supply
5. 14ga wire about 3 ft from the home store
6. Quality wire crimping tool, not the cheap ones that come with the little assortment kits.

A local welder might have a couple feet of wire for you. .030 And .032 wire will also work. It will change the power of the heater, but not by much. You can cut a length of wire, clip each end to a battery and check it with a multi-meter if you want to know the exact amp draws. If you have a whole spool of welding wire, be careful it will spring apart when you open it.

Cut a piece of wire about 35" long. You will lose some wire in the connectors and end up with a heater about 33-34" long. It draw around 7.5-8 amps of power and give you 100 watts of heat. Cut two pieces of 14ga copper wire. I make them about 18" long.

Slip the wire all the way through the connector and hold it there while you push the copper wire into the connector. Crimp both sides of the connector, but only crimp one connector to the stainless wire for now. The connectors have a seem. Make sure the seem is opposite of the stainless wire. Put the connector in the crimper so the round area of the crimp tool is against seem on the connector and the pin on the crimp tool is opposite of the seem. If you crimp it wrong the pin will crush the seem and it will look like this.

If you have the type of connectors that are blocked in the center you can fold over the end of the wire to make it big enough for the crimp to bite it. Make the bend short enough so it stays inside the connector. That will make it hard for the wire to pull out after it's crimped.

Measure a length of fiberglass about 1" longer than the stainless wire. I use a torch to burn the fiberglass before I cut it, but you can get away without it. Burn it for a couple seconds. I take it off of the heat as soon as it turns red. Cut in the middle of the burn so both ends are protected. Some fiberglass rope will stretch longer than others. If it's too long you can always cut it shorter.

Remove the center strands of fiberglass and feed the wire through the fiberglass. I have tried attaching the center strands to the wire and using them to pull the wire through, but it was more trouble than it was worth. I find it easier to pinch the wire through the fiberglass and feed a few inches on at a time. If you crimp both pieces of copper wire to the stainless wire before you feed on the fiberglass it can catch on the connector.

Cut a piece of high temp tape about 4" long. Slip the fiberglass about 1" past the connector. Start wrapping the around the fiberglass about 1/2" before the connector. Wrap it tight, but it will break if you pull too hard. Wrap the tape past the end of the fiberglass, covering the fiberglass. Once one end is done you can pull the fiberglass tight over the wire and cut the other end if needed. Crimp and tape the second end the same as the first.

You can get fancy and add one or more 6" jumper wires by following the same method. The jumpers let the heater span a large gap between the injector lines.

Each vehicle is different, but most 4cyl motors will only need 1 jumper. You should be able to position the heater to get from the first injector line to the second where the lines are close together. Use the jumper from the second to the third line and go from the third to the forth without a jumper. 5 and 6cyl motors should need 2 jumpers. A 4cyl heater with jumpers will need 2 pieces of stainless wire about 17" each. A 5cyl will need 1 7" piece and 2 14" pieces. A 6cyl will need 3 12" pieces (I know all of those measurements don't come out to the exact length, we're not building rockets here). Most V8 motors can be handled with 2 4cyl heaters.