Later model motor swap
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From: Casa Grande
Later model motor swap
In my search for more power and MPG I have often wondered about doing a later model FI, computer controlled motor swap. I know my old 97 with a 4.2/ 5 speed did around 20mpg all day at 70-75 mph and had no trouble towing a trailer with a Jeepster on it. I'd love to get my 85 300/6 close to that. Has anyone here done a swap to one of the later motors with the computer? What all was involved and how does it perform compared to the older setup? I don't have a problem running 60-65 but would love to be able to run with traffic without my mileage dropping so bad.
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It would be much easier to buy a newer truck with the fuel injected six already in it. It's a lot of work, from changing the fuel tanks, all the wiring, etc. Also I would do some research on what people with the later 300 sixes are getting for fuel mileage. I have a feeling it wasn't much of a improvement.
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From: Casa Grande
Yea I could always just buy a newer truck but, I like mine and it would be different. And I do realize it would be a LOT of work and wiring. I see them putting things like LS7's in older cars and trucks all the time. How many times have you seen a late model V8 in an old Chevy? Why can't that be done with our trucks? I think they're better looking to start with. I know I hear about people getting 18-20 mpg with the 300, and I do like the 300 a lot, but there usually talking 55-60 mph where the newer ones do that at 70-75. And the new V6 Ford has in it's F150 is rated at over 350hp and I'll bet it is doing 20-25 mpg to. Just something I'm playing with in my mind while the doctors decide when they're going to let me go back to work.
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Here's the fuel specs for a 87 f150. The L6 is in there.
Gas Mileage of 1987 Ford F150 Pickup
Here it is for a 85 f150. I don't see much difference.
Gas Mileage of 1985 Ford F150 Pickup
Gas Mileage of 1987 Ford F150 Pickup
Here it is for a 85 f150. I don't see much difference.
Gas Mileage of 1985 Ford F150 Pickup
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From: Casa Grande
Yea, on paper by the EPA it doesn't look much different. But from personal experience between my 85 300/6 with 4od and my old 97 4.2/V6 with 5od there was a big difference. My 85 will do 14-15mpg at 60-65 running 31" tires and my 97 would do 18-20 doing 70-75 running 255/75r16 (about 30.5"). I know the 5 speed tranny made a difference in the feel, and thinking about swapping one into my 85, but don't think it was a big help in mpg. Like I said it's just something I'm playing with in my mind so appreciate all the input.
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Yea, on paper by the EPA it doesn't look much different. But from personal experience between my 85 300/6 with 4od and my old 97 4.2/V6 with 5od there was a big difference. My 85 will do 14-15mpg at 60-65 running 31" tires and my 97 would do 18-20 doing 70-75 running 255/75r16 (about 30.5"). I know the 5 speed tranny made a difference in the feel, and thinking about swapping one into my 85, but don't think it was a big help in mpg. Like I said it's just something I'm playing with in my mind so appreciate all the input.
The v6 of smaller displacement is going to get better gas mileage when hooked up to either the 4 speed od transmission or the 5 speed od transmission. This is due to smaller displacement.
The 300 L6 would get better gas mileage than it does now if you'd swap the transmission to the 5 speed overdrive and find another home for the 4 speed. You can also increase your gas mileage by making sure all your emissions equipment is hooked up and running the right tire size for your truck. You probably already know, but the 300 isn't a speed demon.
The v6 is great on mileage and all... but it won't touch the 300's power.
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From: Casa Grande
The biggest thing that's contributing to your gas mileage between the two trucks is the difference in the transmission and the motor.
The v6 of smaller displacement is going to get better gas mileage when hooked up to either the 4 speed od transmission or the 5 speed od transmission. This is due to smaller displacement.
The 300 L6 would get better gas mileage than it does now if you'd swap the transmission to the 5 speed overdrive and find another home for the 4 speed. You can also increase your gas mileage by making sure all your emissions equipment is hooked up and running the right tire size for your truck. You probably already know, but the 300 isn't a speed demon.
The v6 is great on mileage and all... but it won't touch the 300's power.
The v6 of smaller displacement is going to get better gas mileage when hooked up to either the 4 speed od transmission or the 5 speed od transmission. This is due to smaller displacement.
The 300 L6 would get better gas mileage than it does now if you'd swap the transmission to the 5 speed overdrive and find another home for the 4 speed. You can also increase your gas mileage by making sure all your emissions equipment is hooked up and running the right tire size for your truck. You probably already know, but the 300 isn't a speed demon.
The v6 is great on mileage and all... but it won't touch the 300's power.
The 5od might help because it could keep the I6 more in it's power band than the 4od does, something I plan to try. And as soon as I can find a factory tech I want to regear to fit the 31" tires, original on mine was 2.47 with 215/75r15 (27.7") tires.
The simple fact is, newer motors are more efficient designs developed to meet more and more EPA regulations. The up side is more power at the same or better MPG.
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