engine or overdrive?
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engine or overdrive?
I'm trying to determine where my money would be better spent on my 87 f-250, gearing or engine. im trying to reused engine RPM at highway speeds 65-80 it around 3k right now. im looking at a bolt on overdrive or a top end kit both around the same price. The truck is currently making 225 HP and 380 torque with a 3 speed automatic trans with a 3.55:1 finale gear. the top end would put it into the low 500s for both power numbers, where the OD would be a 22% reduction in gearing.
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From: Ottawa, Ontario
No, the truck will require the same amount of energy to get to and maintain a given speed as that is all about curb weight and aerodynamics.
Is that a big block truck? If so anything you can do to decrease cruising engine rpm will reduce fuel consumption.
Is that a big block truck? If so anything you can do to decrease cruising engine rpm will reduce fuel consumption.
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From: Ottawa, Ontario
With the E4OD trans that appeared in these trucks starting in '89 the 460 was capable of achieving low teens at a steady highway cruise, not spectacular but I bet it would be an improvement over what you get now(single digits?). Unfortunately that trans is computer controlled so it wouldn't be an easy swap into your truck.. just in case you were wondering.
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IF you are running a 235-85x16, you have about a 31.7" tire. You have a 3 speed automatic with a 1:1 top gear and a bit of converter slip, and 3.55s you say.
At 65 MPH you should be running 2445 RPM.
At 80 MPH you should be running 3010 RPM.
Limiting your speed to 65 or so should produce good results. Pushing the barn door to 80 MPH probably drops 2 mpg off your 65 mpg.
There is nothing cheap available to fix this issue. An OD, say a 22% Gear Vendors, will cost you $3000+ and will not give you a 22% increase in fuel economy.
Regearing your axles will cost between $1500-2000.
And, sorry to tell you, a simple top end swap, unless it includes a supercharger or nitrous, will not give you 500/500, nor will it improve fuel economy. Quite the contrary.
You have plenty of power, you just need to take your time getting places.
Serving suggestion. YMMV
EDIT: Since the E4OD was mentioned, yes, that is an option. The controller is about $500, so if you get all your parts from a willing donor and don't have to rebuild the trans, you could probably do that swap for $2000 or so.
At 65 MPH you should be running 2445 RPM.
At 80 MPH you should be running 3010 RPM.
Limiting your speed to 65 or so should produce good results. Pushing the barn door to 80 MPH probably drops 2 mpg off your 65 mpg.
There is nothing cheap available to fix this issue. An OD, say a 22% Gear Vendors, will cost you $3000+ and will not give you a 22% increase in fuel economy.
Regearing your axles will cost between $1500-2000.
And, sorry to tell you, a simple top end swap, unless it includes a supercharger or nitrous, will not give you 500/500, nor will it improve fuel economy. Quite the contrary.
You have plenty of power, you just need to take your time getting places.
Serving suggestion. YMMV
EDIT: Since the E4OD was mentioned, yes, that is an option. The controller is about $500, so if you get all your parts from a willing donor and don't have to rebuild the trans, you could probably do that swap for $2000 or so.
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Frmr Ford Trans Engr
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From: SE Florida
It will still need the exact amount of energy at any given speed. Adding more power to the engine means you wouldn't have to push the go pedal quite as far to maintain speed. Gearing is the only factor in how fast the engine spins at speed.
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From: Mi'kma'ki
I'm trying to determine where my money would be better spent on my 87 f-250, gearing or engine. im trying to reused engine RPM at highway speeds 65-80 it around 3k right now. im looking at a bolt on overdrive or a top end kit both around the same price. The truck is currently making 225 HP and 380 torque with a 3 speed automatic trans with a 3.55:1 finale gear. the top end would put it into the low 500s for both power numbers, where the OD would be a 22% reduction in gearing.
Frmr Ford Trans Engr
Joined: Aug 1999
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From: SE Florida
Several years ago a friend had an '86 E-350 with a 460 and a C6. Loaded up it got 5 MPG. He advanced the cam (I think it was 2°) and mileage went up to 6 MPG. One MPG doesn't sound like much, but it means instead of spending $100 on gas he could go the same distance on $80 worth of gas.
When the 460 was emissionized in the '70's they had to retard the cam a few degrees to meet the emissions levels. That cut it's efficiency, but reduced emissions.
When the 460 was emissionized in the '70's they had to retard the cam a few degrees to meet the emissions levels. That cut it's efficiency, but reduced emissions.
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From: Ottawa, ON
A Carbed 460/c6 combo in any F-250/350 was never made for fuel economy in 87.
Here are your options:
1. Ditch the carb and go EFI (aftermarket or stock)
2. Enusre all your fluids are fresh, brakes are not dragging, timing is supposed to be where its set. filters are clean and your ignition system is fresh or in good order
3. Replace the C6 with an E4OD or a ZF 5 speed for the O/D or a Gear Vendors O/D
4. If you are in a place where they don't do emissions or visual inspections then remove all the smog equipment (I doubt this stuff works after 30+ years)
Doing a top end kit on this engine will increase power but will not increase fuel efficiency, realize this is still a 3/4 ton truck with a big block and no O/D
If you are seriously thinking about fuel economy I'd concider doing a 12V Cummins diesel swap with an O/D witch can easily yield 18+MPG with simple stuff done to it.
If that's not your thing and you want more economy then either get a small car to commute or limit the trucks highway miles.
Here are your options:
1. Ditch the carb and go EFI (aftermarket or stock)
2. Enusre all your fluids are fresh, brakes are not dragging, timing is supposed to be where its set. filters are clean and your ignition system is fresh or in good order
3. Replace the C6 with an E4OD or a ZF 5 speed for the O/D or a Gear Vendors O/D
4. If you are in a place where they don't do emissions or visual inspections then remove all the smog equipment (I doubt this stuff works after 30+ years)
Doing a top end kit on this engine will increase power but will not increase fuel efficiency, realize this is still a 3/4 ton truck with a big block and no O/D
If you are seriously thinking about fuel economy I'd concider doing a 12V Cummins diesel swap with an O/D witch can easily yield 18+MPG with simple stuff done to it.
If that's not your thing and you want more economy then either get a small car to commute or limit the trucks highway miles.
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Joined: Aug 2003
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You would probably enjoy reading this:
https://www.460ford.com/forum/37-eng...-86-460-a.html
I agree with others. You will not likely engineer better mileage than the factory. With that 460/C6 combo you can dam sure engineer a better 1/4 mile time.
https://www.460ford.com/forum/37-eng...-86-460-a.html
I agree with others. You will not likely engineer better mileage than the factory. With that 460/C6 combo you can dam sure engineer a better 1/4 mile time.
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