I have a 1988 Ford f350 dually with a 460 fi, 5 spd manual transmission with a 4.10 rear gear.
I have some plans for the truck to give it a helping hand and run better.
Headers with dual exhaust cross over x pipe no cat, don't have emmisions testing.
Increase compression, port and polish heads, along with port matching
possible titanium valves.
Larger throttle body
Upgrade cam unsure what type and profile yet.
Gear vendors over drive unit later on.
Swap to maf along with quality wideband 02 sensors.

Spoke with a rep for megasquirt and they have a direct harness for the 88 f350 460.
It was originally designed for the 1988 mustang 5.0L. It would change the system to a maf sensor, and wideband 02, along with swaping it from batch fire injection to sequential injection.

 

Better is a relative term.

If you want better mileage spend your $$$ on the Gear Vendors OD. None of the other stuff will help much. Titanium valves for your application are a waste of BIG $$$… $200.00 each or more!

 

there are only two things to improve a 460's fuel economy.
1.engine swap (300-6 gas)
and 2.engine swap (diesel)



seriously,the best bang for you buck is do nothing.spend what your about to toss at the engine for a small 4 cyl car and drive that a few times instead of the truck and you'll actually save $ every year.

 

I knew the gear vendors od unit would be my best bet, with the others I do like to tinker and see what I can get out of them. With the valves I do know they are lighter which give a better throttle response. The megasquirt system would be so I can tune on the go along with data recording. So any changes to engine can be set without trouble.

One idea that I did have would be to use an older set heads that have better flow along with an intake manifold for those same heads.
The intake manifold would be drilled and set for the injection system on the truck and a 90° elbow would be bolted to the carb flange with a single bore throttle body instead of dual bore like the factory system. Which could all be retuned with the megasquirt system

 

And with the intake idea here is something similar. Rotate the elbow to face forward

 

Cool intake!

 

gear vendors are great, but itll only benefit you if youre using stockish size tires. with stock tires, and a gear vendor, a rear gear of 4.56 or a little higher would be optimal with a gear vendor...the double OD is going to be deeeep otherwise.


that said, for best mileage you need the following:


-compression bump, the more the better. ive always been just fine having to run 93, it pretty much breaks even when you consider the increased efficiency of having the compression high enough to require it.


-long tubes with a y pipe free flow muffler and a single exit


-ported heads and intake


-torquey cam, any of the speed density cams will do just fine


-block off egr (leaving the rest of the system in-tact and maintained as not to disturb the computer)


-timing on the brink of detonation...advance until ping, back off a hair.


things like MAF, fancy valves, larger throttle body either wont do anything to improve mileage or is too costly to justify the marginal gains. sequential FI is better, no doubt, but at speed the gains are marginal.


start with the above things, youll have one hellofa running 460 and your mileage will improve substantially; all combined with a phenomenal cruise pedal feel...nice and crisp, responsive, light press.

 

I do know the factory heads need exaust porting at the least since it does flow porley, and a raise in combustion does increase fuel burn efficiency so you get the most out of each drop of gas.

Swapping over to megasquirt ecu allows for sequential injection so only one injector fires at a time instead of multiple firing with the banked system. Which means a small gain in fuel economy and power increase.

With the megasquirt system a 4bar map sensor or a maf sensor could be used along with wide band 02 sensors. Can be used for data logging to see how the engine runs with different mods, and to find tune the engine. The possible use of forced induction would also be easier to use and tune over the factory system.

With headers and a free flow exhaust and a less restrictive intak, may not increase fuel economy and power so much with a larger engine. But it allowsthe engine to breath better and remove hot exaust gasses efficiently.

A modified camshaft either a rv or one for efi would be a slight benefit depending on application working with the ported heads.

 

long tubes and ported intake will absolutely help power production and efficiency. just because its a larger engine doesn't mean the rules don't apply the same way.


I wouldn't ever try to convince someone not to got he route you suggested on the tuning side of things, but if you expect large gains over batch fire you will be disappointed. are there gains? absolutely, but its costly, time consuming, and for all intents and purposes the gains are marginal. if you want the hobby, and the data logging/diagnostics, then by all means have at it!

 

i understand that the 460 was never ment to be one for mileage. And I look at it as there are many things that can be done to improve efficiency . It's like parasitic draw , on a smaller engine its more noticeable, you aply the same tricks to remove them on a large engine the gains won't be as large but they are still there. Its like reducing weigh on the flywheel, it allows the engine to put more power to the wheels since it is not having to spin as much weight.

Also aerodynamics play a big role when trying to push a large vehicle.

 

460 can get pretty good mileage actually. I had a 460 dump truck that got 11 unloaded, and truck in my sig got 9-10 with a 302, and I never got over 11. its all in the setup and how you drive...


12-13 unloaded (not city) can be expected from a 460. so can 8-9 if you ride around with your foot to the floor.


do the mods, and with the zf5, I think youll be satisfied with not only how it feels under part throttle but surprised by the mileage you can achieve while effortlessly cruising about.

 

Rite now it gets 8-10 mpg I go visit family for a week I get 5-6 mpg but they live at 10,000 feet above sea level, and I'm only at 4,000 ft

 

 

need I say relatively speaking? . . . 12-13 is a success story in a 3/4 ton gasser.


good song though.

 

Put down the Kool-Aid and slowly back away from the computer.

Big Block Titanium Engine Valves | Ferrea.com

@ $2600.00 for 16 titanium valves your payback in better fuel economy would be…. (drumroll please)… never.

Not trying to be a dick but titanium is the last thing you need.