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Discussion Starter #1
i'm heading for that motor build and just wanted to know if any thing could be done to a 5.8 to get better mpg?
 

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Satyr of the Midwest
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Some ideas:
-- Go roller on the valve train, lifters and rockers (trunnions AND tips).
-- Use very tight tolerances on bearings so lighter oil can be used (5W30).
-- Keep the cylinder tolerances tight so the piston & rings seal in the air/fuel mixture better.
-- Light high-quality components pay off wherever possible, e.g. aluminum heads
-- Get the curb weight of the truck down however possible.
-- Use high-quality headers and catalytic converters.

Those are just a few ideas off the top of my head. :D
 

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Wrenching for a Livin'
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Just don't get too crazy....build it too hot and it will eat more gas

I would just keep the stock heads. Maybe a new intake and air cleaner to get more air, and a GOOD exhuast system. Upgrade the ignition. Degree the cam....
 

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buy a honda
 

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Discussion Starter #5

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Premium Member
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buy a rusty one then for a few hundred.

your in NY, it should be easy to find.
 

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Discussion Starter #7
nah, if its replacing the bronco its gotta be new
 

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nah, if its replacing the bronco its gotta be new
new in NY is just tossing money in the trash can due to all the rust
 

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It's BTW Not AKA!
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As mentioned in every thread on the planet about this, being as you have a 351 you will gain from a Edelbrock intake swap too.
 

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Practicing Infidel
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-Windage tray
-Thermal coating the pistons.
-Low drag pistons.
-Coated lifter bottoms/wheels.
-Timing belt conversion.
-Port matching the intake and exhaust manifolds with the gaskets and head's ports.
-Somebody already mentioned balancing
-Making sure your PCV nipple is relocated from the rear cylinder's intake runner to one of the middle ones.
-After market heads that don't flow TOO much more than stock, such as AFR 165s. Those on top of a 351 would probably build torque lower down too.
-Install a vacuum gauge on your pillar,with the red, yellow and green displays and drive by it
-Upgraded ignition system components and a aftermarket control box
-Much improved exhaust system.
-Taurus electric fan
-Synthetics after break-in
-Stock sized tires, aluminum rims, aired to the max

Sixlitre
 

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for machining, have the block shot peened, decked flat and square the bore to the pistons and crankshaft. Have the crank journals align bored and the whole rotating assembly balanced. Then ditch the stock harmonic balancer and radiator fan. clean the castings on the head and match all your ports. Have the stock intake extrude honed.
 

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Practicing Infidel
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Have the stock intake extrude honed.
You know that's true !

We're dry intake runners just flowing air only aren't we ? I know Carbed heads don't always benefit from extrude honed intake runners, but EFI would, wouldn't it ?

Larston

you're right too and aluminum heads allow a guy to run and extra couple of points on the same grade of gasoline.

On big block Mopars we get away with 10:1 instead of 9:1 on the same grade of gas.

Sixlitre
 

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Extrude honing is something I've never had done personally, but I have an interesting book on it. Shows impressive gains on the stock intake. Specially for a stock or just warmed over motor.
 

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Practicing Infidel
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Extrude honing is something I've never had done personally, but I have an interesting book on it. Shows impressive gains on the stock intake. Specially for a stock or just warmed over motor.
Me neither, but I've ported many a cylinder head

especially in my British days. The one thing they found on intake passages for carbureted engines(wet walls) was you need a slightly rough surface. Exhausts can be shiny as a mirror if you want.

Guess dry runners don't need the rough surface and can get smooth for more flow.

Sixlitre
 

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Discussion Starter #16
lots of things to think about, is it worth the extra cost over just getting a stock re-manufactured block? what kind of milage are we talking about? just did a guesstimated mpg on my last road trip and got around 13-15 mpg highway with 185+ miles on it and some kind of timing issue that i'm working out.
 

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Yeah, realistically if you are building strictly for gas mileage, I don't think you'll get it back.

As to the extrude hone, the process I read about pushes the air and the medium through the ports. Theoreticly the parts that give the most resistance get worn away first. Not so much a polishing as a smoothing of the passage. Removing casting lines and that sort of thing.
 

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Practicing Infidel
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lots of things to think about, is it worth the extra cost over just getting a stock re-manufactured block? what kind of milage are we talking about? just did a guesstimated mpg on my last road trip and got around 13-15 mpg highway with 185+ miles on it and some kind of timing issue that i'm working out.
A bit of ignition and exhaust work

and a fresh plain Jane rebuilt engine could get you 2-3 mpg better than you're already getting, but it don't get much better in a FSB.

Sixlitre
 

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Satyr of the Midwest
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:stupid

The upper teens are about as high as the mileage really gets with a V8 in one of these 6000-lb barns.
 

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My 2 cents.....If / when this engine is done, installed and running, how long will it be before you get payback on mileage?
After all the trick work is done and the Hi Po parts are bolted on
you'll be stuffing your foot in it anyway.
I Get my best mileage with my tires at about 38 p.s.i and unless I'm driving long distance I never fill the gas tank. That extra half tank is extra weight.
 
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