As part of the fuel injection system installation, one must basically add several components to the stock system, and delete others. The plan is to remove all the stock components after the tank and start fresh. The engine driven mechanical fuel pump is another casualty, and that gets removed and a block off plate installed in its place.
A carbureted system uses about 6-7 PSI of fuel pressure whereas the Edelbrock Pro Flo 4 requires either 43 or 58 PSI depending on engine configuration and setup. In sequence from the fuel tank, Edelbrock recommends a fuel pre-filter, an inline electric fuel pump that produces sufficient volume and pressure (assuming one doesn't use an in-tank pump), a second fuel filter of finer media, a pressure regulator with a return-to-tank line, and then on to the engine.
The box the Edelbrock system came in had this sticker which made me laugh. “This kit includes everything you need for a hassle-free installation!” Yeah…right.
Scott and I like to use a marine style, water separating fuel filter that has both a larger spin-on filter element and a clear, drainable sediment bowl underneath. This filter is a 10 micron filter, which is the recommended filtration level for the second filter in Edelbrock's suggested setup, so we’ll use just the one filter in our system. We think having water separating capability is a good thing in a snowcat. Tuckers have large steel fuel tanks, and with a low level of fuel and certain atmospheric conditions, there is substantial concern about condensation inside the tank. Water is heavier than gasoline, so it would settle to the bottom of the tank…exactly where the fuel leaves to go to the engine. Having a clear sediment bowl that’s drainable allows one to check for water in the bowl as part of their snowcat "pre-flight” inspection, and drain it if present.
On both Thundercat and CHUGSzilla we used Airtex brand inline electric fuel pumps. On the 1544 we’re using a Walbro model GSL392 pump. Its output volume and pressure are similar to the Airtex pumps, and meet Edelbrock’s requirements, but the pump’s inlet and outlet fittings are more compatible with the AN style fittings we like to use. After the pump we’ll be using an adjustable fuel pressure regulator that has both a return-to-tank port and uses a vacuum line from the engine, features which are recommended by Edelbrock. The regulator is a somewhat generic Chinese made unit bought from
Amazon.com.
As previously mentioned, we’ll be using custom bent, hard steel lines. To give credit where it’s due, Scott is a veritable genius at bending these lines. You might think there would be a bunch of scrapped steel line attempts laying around, but that’s not the case at all. Rarely does that happen. Now, that’s not to say they all fit perfectly from the get-go, but with a little tweaking, torquing and spiraling (our phrase for the adjustment process) we can almost always make the necessary small adjustments to get the bent line to fit properly. The steel line we use is galvanized, and typically bought from NAPA. They're available in different lengths and NAPA calls them brake lines, but we get them in 3/8” and 5/16" diameter for the fuel supply and return-to-tank lines respectively. We cut them to length and add tube nuts and tube sleeves prior to flaring the ends with a flaring tool that makes a nice 37º flare. It’s definitely more time consuming than using rubber fuel line hose, but we think it’s a superior product and has a professional look. If you buy the fuel system plumbing kits offered by Holley and Edelbrock…they come with something like 20’ of rubber fuel line hose.
The Edelbrock wiring harness has a power wire for the fuel pump, however, there is a limitation of 10 AMPS. So, we’ll use the power wire to activate a Bosch style relay which will supply electric power to the fuel pump. (We’ve used a bunch of these relays in our snowcat projects (just think of all of The Infamous WBJ1’s LED lights) and they work well. The patent has undoubtedly expired, but I sure hope that Bosch guy got paid handsomely for his design.)
We brought the 1544 into Scott’s shop to plan our strategy and talk about the project. We laid out roughly where the fuel system components will be installed, and that also allowed us to make a list of what we think are the required fittings, tube nuts and tube sleeves. I say “we think” because I’m almost certain there will be changes. But it will get us in the ballpark….
In back and forth discussion about the project... project creep has already entered the fray. I know, you’re thinking “Those knuckleheads. When will they ever learn?” Well, all I can say is our intentions are good, and we just
had to make these changes. Yes, Had To!
On both Thundercat and CHUGSzilla we completely rewired the machines and we installed new instrument panels with new gauges and switches. We certainly are not going down the rabbit hole of re-wiring, but the existing instrument panel and switches are just unacceptable, and we can make huge improvements without spending a whole lot of time or money.
A previous owner decided it would be a grand idea to add a radio/CD player to the instrument panel, and they got Bubba and Billy Bob to do the installation. That will be removed and we’ll get a new water jet cut aluminum instrument panel. We already have a couple of instrument panel designs in Scott’s CAD system, so it will mean verifying some measurements and making a few changes. Then that gets sent to Stream Works in SLC where we know they’ll do a fantastic job of cutting the panel. The design of the Tucker instrument panel as it relates to switches is, to use a Navy expression, “poor headwork”.
You climb in your Tucker to use it at night and you decide you want to turn on the heater fan. The headlights are on but they don’t illuminate the switches. You can open the driver’s door to trigger the dome light (so you can maybe read the lettering below the switches), but really? Or you can come up with a mnemonic device to remember the switch layout such as “Fat Henry’s Really Fun Hot Rod”. That would be
Fan,
Headlights,
Rotating beacon,
Fuel pump,
Heater/defroster-
Rear.
But we think there's a better way. We’ll do the same thing we did in Thundercat and CHUGSzilla and install a set of Carling Contura V switches with a descriptive legend and a symbol. Turn the headlights on, and the descriptive legend illuminates. Now you can easily read what switch serves each function. Turn the switch on - and the symbol lights up. While we’re at it we’ll add a switch to turn on the dome light, and we’ll add a second dome light for the rear passengers. In terms of modifications, this stuff is low hanging fruit. Not difficult, yet makes for needed and nice improvements.
