Mpg 460

[sectlandscaping]

I just picked up a 88 f350 mason dump with the 460. I replaced break lines and still have exhaust leak or manifold to fix. I was wondering what you could do to improve mpg? Do chips work? Maybe headers? Any tips on where to start? Would removing the cat help at all?

 

[Skandocious]

Unfortunately the best way to improve mileage on that engine is to replace it with something smaller, haha. It was designed to pull weight and drink fuel.

What kind of mileage are you getting right now?

 

[sectlandscaping]

yeah I understand that. I havent drove it enough but rough estimate is 6-8 mpg. I bought it for dump runs and plowing but I would still like to get double digits if possible.

The exhaust could be leaking from cat or manifold havent pin pointed it yet. It does sound like the manifold but that could be a lifter. So I might put headers on but I think that might hurt fuel economy more.

 

[Truckin4life]

Double digits with that set up? Maybe if you had a 7.3l diesel...
The 460 will drink fuel like a drunk on a free tab at the bar...

 

[5.0Flareside]

ok.... your gonna hate hearing this... but your pretty much stuck with what ya got..

OR....

you could go 2 ways both spending a good bit of money though.

1. change drivetrain. go 351W & ZF5 speed. with a good free flowing exhaust. The reason for the trans wont fit on a 351W from the 460. and 351W's have a ton of power as long as they are healthy and not worn out. and are alot lighter than a 460 and also is pretty decent on gas. 12-16 mpg's

2. keep 460, no chip (they're junk), headers & 2.5" exhaust with a good free flowing muffler. a nice tune-up with a good hot coil, 8.5mm or 9mm plug wires. Fuel filter. and you'll MAYBE.... MAYBE get 10 mpg's on a perfect day with a tailwind and going down hill...

 

[LEB Ben]

Thorough tune-up...headers/exhaust...reduce as much unnecessary weight as possible, and you might get close to 10mpg's.

 

[SuperCab]

6-8 is par for the course with any stock 460... and I can't agree that a 351w would have the needed power in a dump/plow rig... though i've driven similar rigs with 350 chebbys and they were ok if they had the right gears...

people rebuild 460s with higher compression, different cams and all sorts of stuff and get 16mpgs, but it aint a cheap build...

 

[sectlandscaping]

well I might try the headers. Im 90% sure my manifolds are leaking anyway and there in the 3-400 range.

Would a cold air intake effect fuel economy?

I was just curious. I read some rv owners claiming to get 10 mpg and they had to be heavier and less aerodynamic.

So how much use do you think I can get out the engine? Its at 74k right now and its a 88. Will probley only drive 5000 miles a year.

 

[LEB Ben]

Remember with headers, you get what you pay for. Typically, the higher the dollar value, the thicker the flanges which will help reduce the chances of warpage due to heat, as well as a little better fit and finish so surfaces will be true. Along with the better quality, rust issues tend to minimize.

As for the CAI...I'm not a big believer, especially considering most of them draw in underhood temps which are pretty hot, and IMO do more harm than the original intake system.

I usually set a target of 250,000 miles out of gas engines.

 

[sectlandscaping]

Remember with headers, you get what you pay for. Typically, the higher the dollar value, the thicker the flanges which will help reduce the chances of warpage due to heat, as well as a little better fit and finish so surfaces will be true. Along with the better quality, rust issues tend to minimize.

Do you have a preferred vendor for headers?

 

[primetime]

Headers, dual exhaust, good tune up with spiral wrap style wires, K&N filter in the stock airbox, then get some DEI Cool tape and wrap the snorkle, airbox, and intake tubes. Drop in a 180 stat, and get an electric fan off a Windstar (might want to think about a 130 amp 3G alt with the fans, especially since it`s a plow truck). Synthetic oil in the drivetrain also helps. All of this stuff minus the fans made sizable improvement in a test by Performance Unlimited on an 88 460 powered C-350 Centurion Bronco. The tests were covered by Four Wheeler mag in 99.

 

[LEB Ben]

Do you have a preferred vendor for headers?

Vendor or brand??? Vendor...I usually just get most my stuff through Summit, unless the item in question is built by a specialist. If you're talking brand, 460 headers, I like Thorley, L&L and Mad Dog...but you're talking $800+ for all of them.

 

[sectlandscaping]

Headers, dual exhaust, good tune up with spiral wrap style wires, K&N filter in the stock airbox, then get some DEI Cool tape and wrap the snorkle, airbox, and intake tubes. Drop in a 180 stat, and get an electric fan off a Windstar (might want to think about a 130 amp 3G alt with the fans, especially since it`s a plow truck). Synthetic oil in the drivetrain also helps. All of this stuff minus the fans made sizable improvement in a test by Performance Unlimited on an 88 460 powered C-350 Centurion Bronco. The tests were covered by Four Wheeler mag in 99.

I remember hearing about a electric fan before improving fuel. That completely slipped my mind. The question is would I get a different belt? Since the belt turns it or just removing the fan lightens the load? The other one, wont I need a relay and something else to tell the fan to power on?

 

[primetime]

No need for a different belt. Just put the bolts back in that held the fan so the water pump pulley will be held on. To turn on the fan you have a couple of options, you can buy a wiring harness that has a screw in temp sensor and relays, Summit Racing has a couple, or you can get something like a Flex-a-lite adjustable fan controller, which is what I have. However, since the unit only has a twenty amp rating, and I have Windstar fans, which are twins, I chose to put in two relays, one for each fan, and the controller turns the relays on.

 

[460Trucker]

With my 460, I averaged anywhere from 8 to 10 with the stock dual-out exhaust. With my single out Flowmaster, I am getting anywhere from 10-12

 

[mtflat]

Keep it in tune and regular maintenance.

The 88 f250 I had got the same 8-10 mpg regardless whether it was working hard or cruising main street.

The 460 will loaf along pushing snow where a windsor will have to work to do the same task. I've never seen an engine with so much raw stock power. They're just awesome and I wish I still had it.... only sold it cause a friend needed a truck........

 

[Workin' Rig]

If the manifolds are leaking, you are sucking in fresh air through a "Vaccum" effect and drawing in more fresh air across the O2's, which then in turn tells the computer its running lean and it dumps fuel to compensate....

Fix the exhaust and change the O2's, i dont think 10MPG is to lofty to expect from your setup (unless its got some ridculous rear gears like 4.63's.)

 

[bugeye01]

Bill

I just picked up a 88 f350 mason dump with the 460. I replaced break lines and still have exhaust leak or manifold to fix. I was wondering what you could do to improve mpg? Do chips work? Maybe headers? Any tips on where to start? Would removing the cat help at all?

Well, here is my response. First, my long term experience with the 351 is that you will be wasting your time with that engine swap. I have had 351s in smaller trucks and got crappy mileage. And second, I recently bought a F350 with 460 and had to drive it about 1,000 miles home. When I picked it up it ran terrible. A local shop found that it had a plugged catalytic converter and need plugs, cap, rotor and wires. After that it still ran a little rough and they spent another hour eliminating exhaust leaks, which really made a difference. Just some things for you to check that make a difference. On the drive home I drove 65 mph on first fuel load and got 12.4 mpg. The last fuel load was at 70 mph and got 10 mpg. So the best thing you can do once the engine is right is to slow down.

 

[1970Custom]

AND keep your foot out of it... my 85 460 will pull 13 on the interstate, 8 anywhere else, 4-5 when I drive like a mad man...