I've worked woth 460's since the early 70's.

IIRC the stock "sweetspot" for mileage was hit using 3.08's.

Too low (numerically) it lugs, too high and you're wasting fuel by over-reving.

 

I have a 86 E-350 26' Motor Home. I know that it has to much gear, She was designed to run 55 and no more. Running 55 in New Mexico is bad, everything will run over you! But if i try and run 75 i get about 5mpg! I am wanting to have the "sweet Spot" 65 to 70, And sugestions for gearing?/

 

Update , I have Axle type 53. So it is a open 3.55 , That was the lowest gears ford offered in that axle.

 

If this is the 10.25 rear axle, while Ford may not have offered it you can get 3.08 from summit racing.

There is an article somewhere on FTE that decodes the plates but I can not find it. I need a day off so that I can sleep and recharge myself. Next week I am not going hunting. Sleep first, Bambi latter.

 

It was the FTE post that gave me the info. I need to get a Tac doe see what RPM I am running at different speeds.

 

KRDiesel
I want to clarify that what I should have said is that this "sweetspot" was often true in 4X2 pickups. Motorhomes are another game entirely.

With all the added weight that I know you are carrying and no doubt additional wind drag a change to 3.08's might not give you enough oomph with the additional drag. The 3.55's might even be a little high speed for an RV I changed over to 4.10 for handling my camper.

 

Yea, I was thinking about that myself. I need to get a tach and see what is going on. Then go from there.

 

What about with my 4X4? I have been thinking about 3.08 gears for a while but due to cost it is on the back burner for now.

 

my guess is that a HHO generator would help quite a bit....see HHO generators on utube.com

 

No thank you. I do not want to be running my engine that lean. If the feed hose breaks you risk burning up your motor.

 

just a thought...but the outputs are not that much as to cause an explosion...as soon as the gasses hit the air they dissipate very quickly.Most engines are running on the rich side as the fuel is not entirelyl being burned..this is why the HHO helps...it allows the fuel to burn more completely cooler ,cleaner...thus more efficient..
tough quest to make a big volume engine drink less..good luck

 

for HHO to work as intended you have to trick you car into running richer than normal. If you end up breaking a feed line you will be running your engine at a very rich setting and that will burn your motor.

I did not mention explosion in my thread as that was not what I was talking about.

 

if a 2.0 litre motor gets 45mpg, and a 4.0 litre motor gets 23mpg(if your lucky) then a 7.5 litre motor(aka460) would do well to get 13 to 15mph.its just a big air pump,with more air you need more fuel,no way around it(14.7 to 1)you may lean it out but you ruin your ability to make power and if you dont need the power put in a smaller more fuel efficient motor.i get 12mpg in mine in a 5400lb truck 38' tires with headers and dual exhaust,stock carb, cam and compression.makes lots of power but not very fuel efficient.

 

My 429 got 16 mpg in a heavy 1969 Galaxie with 2.73 gears. I know that's not a truck, but it was a bone stock 1969 429 with a 2V carb.

 

Heh, maybe with zero gap rings, 13to 1 comp on propane, but 20mpg? Dont think it can be done. I herd of caddy 500ci's doing 18 to 19, but they are a better designe.