Improve Fuel Economy on 360

Just because you're running as much ignition timing as you can without ping doesn't mean the engine is running at peak power and efficiency.

     This is the first I have seen anyone mention calculus on the forum.  I am an engineer and have had calculus, physic, statics and dynamics,thermal dynamics, fluid dynamics,  etc.  You are correct about the piston firing after TDC and having the best leverage. The same with fuel combustion. 
     Factory setting are generic.  Consider them a baseline.  All engines are different.  Whether it is the carburetor, plugs, wear on the timing chain and engine, or even changes in temperature.
     I for one have always base lined my engines and then carried a timing light with me in the car.  I try adjusting the timing a degree at a time.  Once I hear pinging (usually going up a hill) I back off the timing.  Then I back off a degree at a time until I feel I have hit a sweet spot. You can do this over a few tanks of gas and get a real feeling or where your cars runs well.  You will definitely loose performance to gain a little bit of mileage.  But, there is a few miles per gallon to gain. By driving you car right an having a good tune on your car.   

FSJunkie wrote: As said, if I can average 13 MPG combined highway and city in a 4000 pound Wagoneer, you should be able to get 17 or so in that. It weighs a couple hindred pounds less with a more efficient transmission and is more aerodynamic.   Factory AMC axle gearing for the auto boxes tends to be pretty good all around.  The 2bbl carbs are the best fuel economy and low torqueing carbs ever made, but a slight increase in mileage can be had with a carb off a later Jeep 360.  Motorcraft made quite a few improvements to the carbs in the name of power, fuel economy, and emissions, all of which improve together.   The exhaust system might be too big. If they're duals, I hope they are no bigger than 2" each pipe.

Well, I sure dont agree with what you said here...........I have put 2 1/2 inch pipes on stock engines....and its been proven that all 2 bbls were just cost cutting measures for the factories when they were not concerned with fuel economy.   (If you look under the last mid 80's V8 cars, particularly GM, and chrysler, and some Fords, you will see that the majority of the carburators are 4 bbls, why? because a 4 bbl has smaller primaries than a 2 bbl will.......and that is where fuel economy is at...........remember, the factories had to meet the 27.5 MPG average)  I will concede that the motorcraft is a good carburator, but its not a 4 bbl. and I have converted cars to a 4 bbl from a 2 bbl and the 4 bbl would average anywhere to 1-3 mpg better. and my gremlin was one of those cars too.

purple72Gremlin wrote: I have converted cars to a 4 bbl from a 2 bbl and the 4 bbl would average anywhere to 1-3 mpg better...................     Just my opinion...............advance the initial to anywhere to 8-12 BTDC.  make sure your choke opens quickly. and make sure your choke pull off is working as well. and make sure the power valve in the carburator is working.  put some good plugs and wires on it. (my preference is no champions)  get a distributor cap and rotor from blue streak. they are a set, and the cap will have copper terminals. put a vacuum gauge in the car and try to keep it above 15 inches at all times. also a tach, and try not to go over 2500 RPM.  If you do this, I believe you can increase your MPG by 1-2 MPG.

Years ago, for a project with one of my electronics classes, I made a poor fuel economy minder. Mine used comparators, a vacuum can to turn on a red, yellow or green LEd depending on the manifold vacuum.