More Mods for the Rollback.

[Silver91Hatch]

Well guys I have been using my 1986 F-350 Rollback more and more here recently and I have noticed a couple things about this IDI. Headlights suck, likes oil and likes fuel. So I decided with a free day today(mostly) I would try to help out these issues.

First off the headlights. When I bought the truck, if you ran the high beams it would trip the breaker in the headlight switch, and you had to run highbeams after dusk if you wanted to keep it between the ditches. So I did the relay addition to the wiring and it went from candles to laterns, lol. I thought it was great. Before I had approx 7-8 volts at the lights, now I have 11-12. But I was going to upgrade other items on the truck soon so I know I needed a real alternator. So today I pulled the 3G 130A-er off of my 1991 Mustang Coupe that is getting an engine rebuild to put on my truck. The first thing I noticed after the install the Amp guage was reading about 3/4 of the way up on the Charge side. and I had 14.4V at idle, secondly my lanterns are now flashlights.

Mod #2. I have checked and added oil everytime I stop for fuel(one tank working right now, so 300 miles) and I have noticed that the truck uses/leaks about a gallon of oil every 1000 miles. So I did some trouble shooting today and noticed that the valve cover gaskets are leaking horribly. So I decided to swap them today. The PO had broken the long alternator bolt off in the alternator and decided to leave it there so that was fun getting it out. So after that all went smooth, replaced the gaskets and hopefully that will cut down on the oil buying.

Third on the list is fuel mileage. I haven't done much research on this subject so please if you have any ideas let me know. I decided to remove the mechanical fan and install 2 Taurus fans that the 5.0L mustang crowd loves, and plus I had them laying around. This is the real reason for the alternator swap. After trimming them all the way down I still can not get 2 Taurus fans to fit on my radiator. Its 24x31 and I can only get them trimmed to 34". So I decided to put the mechanical fan back on for this week and I will work on it next weekend. Does anyone know what kinda CFM this mechanical fan pulls? At idle I can feel no air moving infront of the grille and my temp guage creeps up when I drive it loaded. I'm 99% sure my clutch is shot. So I was wondering if 1 Mark VIII fan (approx 4500-5000CFM) will suffice on a truck that is loaded with 4000+ lbs 90% of its life or do I need 2 Taurus fans (3500 CFM each approx).


Specs on the truck in sig. Additional specs. 4.10 gears, almost 100% stock. Headlight relay mod, 3G alternator.

 

[LCAM-01XA]

The e-fan vs. mechanical is an ongoing debate, some say e-fans are a blessing some say they are a curse when you run leaded good. The best way to find what is true and what is not is to try each - so far it seems to me that your factory fan sucks, likely cause of the clutch not locking up properly. On my truck the fan clutch is bypassed so the fan is turning at full water pump speed all the time, I have this big heavy camper on my truck good 3/4 of the year and even foot to the floor climbing a long grade my temp gauge stays on the cool side (factory gauge, not the most reliable thing, but still fairly consistent day in and day out). Several other folks here have done the same, as it leaves no places for ifs ands or buts when it comes to engine cooling, but you will pay more at the pump due to the increased accessories drag on the engine. The e-fans, two of them Taurus ones may just do the trick for you, so by all means go ahead and try them and see how they fare - obviously take it easy on the test run and watch the gauge like a hawk, and make darn sure you have the fans wired properly and also install an override switch that will power them both on their high speed should something go wrong with your temperature probes or whatever you plan on using to control them...

 

[Silver91Hatch]

Well I know the E fan on my Mustang gained 8 RWHP and a little under 1 MPG on a poked and stroked FoxBody. The way I run my electric fans is they come on low speed as soon as the key is in the run position(would have to be changed for the truck) and I have a High/low switch that I can toggle between.

Right now I am running just a straight air cleaner with no ducting so I am planning on making a CAI after I remove the mechanical fan and that will clean up the front of the engine bay so I can plumb it all up.

 

[LCAM-01XA]

You already have a CAI from the factory, the duct goes to a rather large rectangular hole in the rad support under the driver-side battery tray. At least that is what should be in there, obviously your ducting has been removed. I actually threw away the restrictive over-the-battery factory ducting my bricknose truck had, and retrofitted an '80s factory ducting in its place, the kind I just described is what I now run in my truck and I have no problems fitting it in even with the factory B17 propeller of an engine fan.

 

[Silver91Hatch]

Yeah my stuff has been broken and missing since I have owned the truck. I am going to duct it from under the front bumper area to the air cleaner with 4-5" ducting or aluminum tube.