Mileage Quest 2011!

[woods]

Normally...a four barrel with get better mileage than a two barrel (as long as you keep your right foot out of the secondary.)

[cdeal28078]

Clint, it probably doesn't help that my truck weighs about 1700 lbs more than yours and has 2/3 the horsepower and torque at best.[/quote]
I doubt it really. My 460 is very mild with low compression heads on it. Not a real screamer. IT is fun though.
I would venture to say your shroud makes the difference.
I have the heavy duty 7 blade clutch fan on mine that came with the 460. It is pretty quiet and seems to cool it well.
I also agree that a smaller 4v carb. will usually get better gas mileage than a 2v. A 2v will usually feel like it has more torque when putting around though. The 1st time you bring in the secondaries on a 4v carb though your gas mileage has gone down the tubes.
clint

[tmcalavy]

Went out after work today and hooked my dist. up to manifold vacuum on the rear of the 360 in my 69 F250...there's a splitter there. Also plugged the port on the carb that I was using, and really like the engine response now. Like woods says, it wakes your engine up. I'll know in a week or so if it makes a difference in mpg...I'm getting 12.7 in town driving right now.

[edglenn]

So.....what was the final, best mileage?
For that matter, what's the best mileage anyone's got?
Is 14-16 MPG for a stock F-250 with 390 2 bbl too much to hope for?
I'm getting 8-10 MPG right now, but haven't worked the bugs out yet.

[woods]

I got 44mpg.......going down willamette pass.

[Mancar1]

Since I only drive the 68 maybe once a week anymore. Just for the pleasure of it. I'll call it 50MPG. Course when I actually drive it it is.......11MPG

[fomocoguy]

The best I got with her was a little over 13 mpg. Honestly I don't think I'm going to put any more effort into it; I can deal with 13 for now. I'm trying to re-focus my energy on the 300 6-cyl I'm building. I managed to clean up the combustion chambers and do some light port work on it, but that's a subject for another thread.

[MaiTai]

Hello - where is the vacuum advance hose supposed to be plugged into? Anyone got a picture? Thanks

[edglenn]

The distributor vaccum advance hose goes to a port on the base of the carburator.
There's also a port in the intake manifold, behind the carb, that can be tied into. I believe that the larger port in the manifold provides more immediate vaccum, and helps the distributor advance more quickly, which helps with acceleration.
I think Ford didn't configure the engines that way due to wanting to retard the vaccum advance at low idle for better emmissions.
Maybe Woods can elaborate on why it works better. Is this right?

[woods]

I did, go back a few pages...I got very long winded.

[Donnie]

I rented a 26' U-Haul the second week of January this year and it had a vacum gauge hooked up to it that had green and red zones on it that showed "best mileage" and "worst mileage". You romp on it and it would go into the red zone or if you took it easy you could keep it in the green "best mileage" zone for the most part. I bet someone makes a kit that has the red and green zones or best worst zones what have you. Or you could even just get a vacum gauge and try to keep as much vacum as possible on it while driving. I was amazed how much I watched it and kept my foot out of it. Might help you not romp on it too much.

Fuzz

Fuzz, before electronics hit the auto industry--THE MOBIL GAS ECONOMY RUN--coast to coast The vacuum gauge was the most reliable instrument that the drivers would depend on.....
I still use one in my Travco................Donnie

[MaiTai]

Ok thanks - I plugged my vacuum advance hose into the port on the intake manifold behind the carb and it made a world of difference!

[Timbo]

Barack Obama would be proud of this thread!!!!

[woods]

Should be.

[cdeal28078]

One thing I think is overlooked is the accelerator pump,cam and nozzles. Think about this.. every time you give it just a tough on the gas peddle there are two streams of pure gas being feed to the carb. Now think about how you have seen some people drive...on and off the gas so much you get sea sick. I hate to think how much gas they waste by doing that. My dad is a retired trucker of over 37 years and is one of the smoothest drivers I have ever seen. He judges all of the traffic lights and hardly is ever stopped by them. Before his 93 F150 5.0.OD truck with 3.55 gears was totaled (the one I am working on now) he was getting anywhere from 19-23 mpg with it. The 19 was cruising around the back roads around 45 mph. The 23 was on road trips.
My 71 F100 when it was s stock 302 and a three on the tree with 3.25 gears could get 18mpg with ME driving it on a trip if I stayed around 55-60. Back then there was no 65 mph zones around here.
Decent mileage can be had with some of these trucks.
On these huge 4x4 F250 you don't have to be happy with 6-9 mpg I don't think. I think there is always room for improvement.
Especially if the carb. is all out of adjustment and the timing curve has never been set.
clint