A Mileage Experiment
Improving the economy of an old pickup
7-9-2006
The Pickup
1965 Ford F100
240 ci engine (bored to 247) (professionally
rebuilt)
TOT transmission (factory 3.03)
2.75 differential (changed from 4.10)
Manual steering
Manual brakes
No bed (will be installed later)
Modifications still
to be done (considered)
New
235/75R-15 tires (donated 5-13-2006) -- Done
Timing/Carb adjustments -- Done 5-14-2006
Synthetic Transmission Fluid
Synthetic Differential Fluid
Synthetic Motor Oil (after break in)
T-5 Transmission ? ? ?
Wheel Alignment
Muffler Replacement
Replace oil bath air cleaner (OBAC) with paper
type
Electronic Ignition
Replace Intake Manifold
Replace Exhaust Manifold
Replace 160 Thermostat with 180, 190, 200, ...
Install bed
The First Tank
Eager to try out the pickup after
working on it in the garage for three years, I drove it for about
a week without performing any fine tuning/timing and with the original
truck tires. The engine had 0 miles on it. There were some
mechanical problems like a poorly installed front suspension bolt
causing a tremendously hard ride. All of the miles were slow
speed (city), partly because the engine was new and partly because of
the front suspension problem. I covered 110 miles on 8 gallons of
fuel (~14 mpg). Not satisfactory at all, but I had to start
somewhere. Maybe the mileage will pick up after the engine breaks
in.
The Second
Tank
A slight leaning of the idle mixture
resulted in a mileage improvement from 14 to 16 MPG. But the
engine was running pretty terrible. Time for a decent
tuneup.
The Tune Up
I removed the 1/4" NPT plug to
the intake manifold and
replaced it with a 1/4" barbed fitting. I connected a vacuum
gauge to
the fitting. I then adjusted the carburetor for optimum
vacuum. Once
reached, I adjusted the timing for maximum RPM. I then readjusted
the
idle mixture screw for max vacuum. Another readjustment of the
timing
for maximum RPM. And then I did it all one last time. The
vacuum
gauge read 17 inches. The engine was running pretty smooth.
The Tires
Five Hankook 235/R75-15 highway radials
were donated and installed. I wanted to replace the wobbly rims
also but monetary constraints prevented this from being done at this
time. (If anybody has any straight 15x7, 5 on 5.5 rims, please
let me know). I also repaired the front suspension fixing the
problem with the front right swing arm pivot bolt. Now the truck
drove reasonably bouncefree.
The Third Tank
With new tires and a tuneup, I was able
to travel at highway speeds (well OK, highway speeds for me -55
MPH). I decided to take my assistants for a ride up a local
mountain. The total trip was 100 miles, 76 of them flat and 24 up
(or down) an 8% incline. I first noticed the temperature gauge
rising above its normal 170 degrees to 190. As we were driving at
highway speed, I ignored it, other than to watch it for indication of a
mechanical problem. None occurred and the temperature dropped
back to 170 when we pulled over to a rest stop to walk the dog.
Climbing up the mountain was a breeze. I had to downshift
eventually into second for the final climb but, other than the
temperature gauge rising to 205 (we were hauling a##), the truck
performed great. I drove the 12 miles downhill on the mountain
with the engine off. I figured we didn't have power steering, nor
power brakes, nor an automatic transmission, so why waste fuel running
the motor. The final result was 164 miles travelled overall, 8
gallons used resulting in 20.5 MPG. We are getting there!
The Fourth Tank
Due to tasks that needed to get done,
I did not have an opportunity to drive any highway miles on this
tank. I covered 160 miles on 8.1 gallons resulting in 19.9
MPG. The engine seems to be settling in very well. It has
clean acceleration and idles smooth. It looks as though I can
expect close to 20 MPG city. I will try another tank at city
driving and one more at highway before I change the engine oil at the
rebuilder's recommendation (500 miles).
I am thinking that the next modification will be the muffler (any
thoughts?). The muffler looks like a factory style
original. It has rust and is vveeery quiet (I startled two men in
a parking lot when I pulled up behind them). I am guessing that a
minimum back pressure type will enhance mileage. I don't know yet
about the noise effect. Will have to do some muffler research.
The Oil Change
I changed the oil at about 600 miles. It looked OK. No metal filings or rod nuts :) I replaced the oil with 10w-40 (what was in it). I'll try a few more tanks of fuel before I make any changes. Hopefully a couple of tanks at highway speed and a couple at city.
Two More Tanks
Well, two more tanks, all city. A little bit worse mileage (19.2) but otherwise no problems. A sibling is visiting me and refuses to ride in an old vehicle so I will be renting a car for the next week or so. When I return, I will do a couple of tanks at highway speed. I am very interested in determining the truck's current efficiency at higher speeds to develop a reference for determining the improvement in economy when I convert the differential and tranny to synthetic fluid. I don't think synthetic tranny fluid has much effect at low speeds and need some reliable numbers with which to compare the two types of fluids and their effects at higher highway velocity.
Back from Vacation
Vacation with my sibling is finally over and I have started back with the pickup. I rented a Yukon for the vacation. What a nightmare. That Yukon had more unnecessary options than I could even imagine having on a truck. The first night I camped in it, it took me an hour to figure out how to turn off the dashlights, and the alarm went off three times. I am so glad to get back to my non-complicated little truck.
Well I put another 225 miles on it (11.5 gallons), all city. Still around 19-20 MPG. I have been having some trouble restarting the engine after it sits for anywhere from 30 minutes to a couple of hours. Instead of kicking right over, it has to crank for about four or five seconds, almost as if it got flooded somehow. I will have to look into it.
OK - Ready for some Highway Cruising
I finally got my emergency hood latch from LMC today, along with a new main latch and new visor clamps. With the backup latch I can now do some serious highway traveling. I started with a little 60 MPH cruise just to see what old technology felt like at higher speed. The truck had decent pickup and pep (I am now wondering if I could have gone with a 2.48 rear end instead of a 2.75). But the temperature gauge seems to rise a bit. Instead of 170 degrees, it was running steadily at 195-200. I am not too sure if this is supposed to be normal or if I might have a problem. Any info is appreciated. Anyway, I am looking forward to this weekend!
Some Minor Setbacks
I have been smelling traces of gasoline ever since I started driving the truck. I have also noticed stains on the carburetor. Somehow fuel is leaking through the top of the carburetor. Not enough to be visible when viewing the engine compartment, but enough to stain the carburetor and cause an aroma. I don't want to record mileage if it is tainted with a carburetor problem.
Also, Tucson seems to have jumped into the monsoon season a month early. It is either over a hundred degrees outside with high humidity, or raining. And I have been trying to sandblast and paint the bed, as well as repair the T-bird so that I can get it out of the garage to repair the truck. Also, the dashboard lights have died on me. I haven't been able to work on it because of the T-bird (and the heat). And I just discovered I have a flat tire that needs immediate attention. Rest assured though that I will be tackling these annoyances, one at a time. And as always, any help (suggestions) are appreciated.
_____________________________________________________________________
Stay tuned for updates.
Dr. Pepper
And as always, we
accept unwanted telescopes
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