Excerpts from my daily newsletter bloggy thing http://outfitnm.com/category/brians-morning-newsletter
We had 15 below zero here in northern New Mexico last month, and that killed another $30 fuel filter because of residual biodiesel in the tank. I needed a plan to preserve fuel filters longer than a month or two.
Turns out the Flat Plate Heat Exchanger (FPHE) did the trick.
Below, the fabled HPHE, mounted on the firewall of the Isuzu Trooper.
I had fun fabricating the three metal brackets which hold the FPHE to the firewall. The snow covering everything outside including all of my metal stashes made locating the proper pieces difficult, so I cut this metal from a salvaged electrical box. I’m just getting used to the metal cutting bandsaw that Louie lent us. It cut through this metal making strips which I then shaped on our homemade anvil and further bent and formed the metal with a chisel and the vice. The color is brass, which I used to weld (braze) the whole thing together.
This is the fuel filter that came from the WVO setup. I looked this up online (the website is posted right there on the label, I love the Internet) http://www.davcotec.com/ not a great site, and I figured out most of what I know on my own about this amazing filter. Fist off it says right on the label that it is a WVO and or biodiesel fuel filter. Sweet. This almost made me employ this thing, except for two issues: 1: I just ordered two Isuzu fuel filters at $25 each. 2: this thing is huge. It was going to be a tight fit getting this in the engine compartment.
After examining this Davco filter I see that this is a heated filter. So I went back to the original idea of using the FPHE on the Trooper to heat the fuel before it goes into the filter, because everything I’ve read suggests that the cold weather makes biodiesel turn into waxy flakes and this is what plugs the filters. This seems true from me experience. When try to clean out a plugged filter it is full of flakes, and lately frozen moisture.
The next day, I hustled and got the Isuzu plumbing modified to accept the flat plate heat exchanger – fuel heater. Fortune favors the prepared, and it seems everything went smoothly for the kid, even when I learned that one of the coolant hoses which I planned to cut into and tap for a heat source was thoroughly rotten.
It worked out because I had a new piece of rubber hose which was long enough to reach, and it didn’t need a pipe splice. It was a bit difficult to reach the point of origin of the pipe I was going to plug into, but it worked out and for a change I managed to accomplish the task without giving myself any skinned knuckles.
Once the coolant lines were connected, I began to work on the fuel lines, one issue I had to deal with is the new fuel filter wasn’t here to install, so I took the old plugged filter off and cleaned it for probably the third time. I know my luck is bound to run out with the filters and probably sooner than later, so it is comforting to know the parts are at least in town, and in a pinch I can swap out the filter on the road.
Last but not least for my flimsy plan to get myself to work today, I had to try and start the diesel engine with the glow plugs disconnected. Yeah, never mind on that one, the engine didn’t even try to fire, even with the vehicle having been in the warm shop all afternoon. Glow plugs in case you don’t know, are sort of like spark plugs in a gasoline engine, except in a diesel they are only used when the engine is cold. After that the engine fires solely on the much greater compression of fuel found in diesel engines. Hence a diesel engine is called a “compression ignition” system.
Anyway, all the glow plugs are tied together electrically with one rail, which I had removed in preparation for the new plugs being here in time, a plan I can now look back on as being timed a wee bit optimistically. I had no choice, I had to replace the rail and hook up the old glow plugs, if I wanted to use the Trooper which has all my tools and supplies in it, to get to work in today. It wasn’t so bad, but then ask me again on Monday, how it was when I have removed and replaced the glow plug system twice.
Here it is, the heat exchanger mounted on the Trooper firewall. Black hoses are for coolant. The red hose is the fancy and expensive biodiesel resistant Vitron rubber hose. In the middle of the bottom of the photo is the original Isuzu fuel filter with a hand operated primer pump on top, which I don’t need anymore because of the lift pump which supplies constant fuel to the injection pump.
Another view of the project, in the above image you can barely see the square shape next to the fuel filter, that’s the Facet brand lift pump. Also while I was in the vicinity I replaced the battery negative cable which connects the battery to the frame. The new cable is black the proper color for a ground, unlike the red cable which someone else replaced before I got the truck, that one goes to the engine ground. I always need to warn people when giving their car a jump start that the cable is colored improperly. At least I ought to put black tape on the cable.
In summary, the heat exchanger is super easy to install, and if there is even a little bit of biodiesel in the tank when the temperature drops like it did here in northern New Mexico last month, it is going to gel, and it will plug the filter. Autozone sells the Isuzu diesel fuel filter for fifty plus bucks, forget that. I found a better way
Yesterday the Trooper ran better than it has in a long time.
The moral of the story, hot fuel burns better than freezing cold fuel :cheers: