How can i improve a lil bit on gas mileage

[383Chevy]

I have a 383 stroker with dart heads single plain intake and a 600cfm holley 3.23 gears highway stuff, i get up go to the gas station get $10 worth wich is about 2.5 gallons of gas, go to school wich is barely 8 miles away come home dont go anywhere get up the next morning all my gas is gone whats the deal here? i have a locking cap so noones siphoning my gas idk what more to do specially with gas prices the way they are.

[N2TRUX]

Originally Posted by 383Chevy

....go to the gas station get $10 worth wich is about 2.5 gallons of gas......

It's because you have "a 383 stroker with dart heads single plain intake". That single plane and those Dart heads are designed to flow fuel, not sip it. Great for grins, but not so much for MPG.

Best solution is to park it and buy a cheap small car or truck.

[Restrorob]

Originally Posted by N2TRUX

Best solution is to park it and buy a cheap small car or truck.

Ditto !

Or maybe slide a block of wood under the gas pedal ?

[383Chevy]

Originally Posted by Restrorob

Ditto !

Or maybe slide a block of wood under the gas pedal ?

I drive the speed limit even under to save gas lol and i thought about parking it but i like it but theres gotta be a way to get better we built a 388ci in a corvette and it got 16-17 mpg with aluminum heads

[Restrorob]

Have you checked for any fuel leaks, Like the tank sending unit hoses ?

What tranny you run'n ?

BTW, I'm hotter in Fl too....

[383Chevy]

Originally Posted by Restrorob

Have you checked for any fuel leaks, Like the tank sending unit hoses ?

What tranny you run'n ?

BTW, I'm hotter in Fl too....

Havent checked for leaks but ive been wanting too just havent got the chance also running a th-350

[lilpoindexter]

Originally Posted by 383Chevy

I have a 383 stroker with dart heads single plain intake and a 600cfm holley 3.23 gears highway stuff, i get up go to the gas station get $10 worth wich is about 2.5 gallons of gas, go to school wich is barely 8 miles away come home dont go anywhere get up the next morning all my gas is gone whats the deal here? i have a locking cap so noones siphoning my gas idk what more to do specially with gas prices the way they are.

[383Chevy]

Originally Posted by lilpoindexter

Whats so funny? i didnt ask for any smartass remarks thanks though

[Restrorob]

I'd pull a couple spark plugs and see if their black from running too rich, If their not black start hunting for leaks. I just can't fathom that SB drinkin gas like that, My 502 LUVS it but still gets 13 mpg....

[383Chevy]

Originally Posted by Restrorob

I'd pull a couple spark plugs and see if their black from running too rich, If their not black start hunting for leaks. I just can't fathom that SB drinkin gas like that, My 502 LUVS it but still gets 13 mpg....

I will check that tomorrow im in the mixed of getting a GOOD air cleaner too, thanks you seem to be the only one helping

[oldblue1968chevy]

383, chill.

Your setup is not going to pull the best MPGs, these heavy trucks arent exactly aerodynamic either. Id triple check timing, maybe set carb. with vac guage and go easy on the pedel. Maybe think about OD trans in the future?

[383Chevy]

Originally Posted by oldblue1968chevy

383, chill.

Your setup is not going to pull the best MPGs, these heavy trucks arent exactly aerodynamic either. Id triple check timing, maybe set carb. with vac guage and go easy on the pedel. Maybe think about OD trans in the future?

I am chill but laughing at something thats not a laughing matter is stupid, im pretty easy on the pedal i dont speed or lead foot i dont have the money for that does the 700r4 only had OD or does the th-400 have it?

[zackary027]

no one means to be mean its just there's not much hope for our trucks with horse power like a 383 puts out. change the intake put on a quadrapuke on top of it if you dont have to demanding heads and cam, change out the gears in the rear end, but even then maby a maximum of 15 mpg

[383Chevy]

Originally Posted by zackary027

no one means to be mean its just there's not much hope for our trucks with horse power like a 383 puts out. change the intake put on a quadrapuke on top of it if you dont have to demanding heads and cam, change out the gears in the rear end, but even then maby a maximum of 15 mpg

I still think i have a good leak i was getting 14 with 4.11 gears a couple months ago its even cut to 2barrels instead of 4 its the damndest thing i cant figure this truck out i was getting almost 16mpg with 4.11s and 315 drag radials i put 33" a/t's and i went down to 14 then down to 10 then back up and back down switching back and forth from 2brl to 4brl, i know the filler hose has a small crack at the end so i spill a lil bit of gas out while pumping but its got to be evaporating or something from somewhere i already had a fuel inlet nut leak and i took care of that

[Restrorob]

Originally Posted by zackary027

but even then maby a maximum of 15 mpg

Just a side note; I drove my 74 as a DD for 8 yrs, Stock 350 2bbl turbo 350 and the BEST it would do is 10.5 mpg even after a carb rebuild and EVERYTHING in the ignition system new and fine tuned....

[383Chevy]

Wouldnt a manual 4 speed help with mpg? we just had a 85 suburban 3/4ton 350 with the 4 speed got close to 17 mpg's

[87 V20 Scottsdale]

What about trying a lower rear end gear, like 3.73. You said you were running 33 inch tires, with a 3.23 rear end. That would be similar to a stock tire turning a set of 2.73's. No matter how powerful an engine is, it will always take a little more effort to turn a taller set of gears.

The chart in this link may be able to better get my point across.
http://www.4lo.com/calc/geartable.htm
Yellow = better economy
Green = everday driving
Red = more power

[87 V20 Scottsdale]

Mongoose beat me to the punch, 1600 RPM is lugging the motor.

[383Chevy]

Originally Posted by 87 V20 Scottsdale

What about trying a lower rear end gear, like 3.73. You said you were running 33 inch tires, with a 3.23 rear end. That would be similar to a stock tire turning a set of 2.73's. No matter how powerful an engine is, it will always take a little more effort to turn a taller set of gears.

The chart in this link may be able to better get my point across.
http://www.4lo.com/calc/geartable.htm
Yellow = better economy
Green = everday driving
Red = more power

I may look for some 3.73's initially i thought they were 73's till igot them and counted and it came out 23's ill see if i can find them though thatd prolly help out a bit

[87 V20 Scottsdale]

Is your truck 2 or 4 wheel drive? My 383 has been getting 10-12 mpg, depending on how it's driven.

[383Chevy]

Originally Posted by 87 V20 Scottsdale

Is your truck 2 or 4 wheel drive? My 383 has been getting 10-12 mpg, depending on how it's driven.

2 wheel

[mongoose]

get a vaccum gauge and learn to keep it all the way to the right.. ='s best mileage for what you got...

you still running the 33's? i'd put the 4.1's back in... especially if you're not doing and highway.. ie cruising at 50 or w/e should make the engine run a lot easier.. thus use less fuel even though you may turn a couple hundred more rpm.

[383Chevy]

Originally Posted by mongoose

get a vaccum gauge and learn to keep it all the way to the right.. ='s best mileage for what you got...

you still running the 33's? i'd put the 4.1's back in... especially if you're not doing and highway.. ie cruising at 50 or w/e should make the engine run a lot easier.. thus use less fuel even though you may turn a couple hundred more rpm.

4.11's got stripped out so 3.23's were all i got but with the 4's it screamed like 2400 ish rpm im at 1600 rpms at 55

[cableguy0]

You killed your mileage in the process of trying to find more. Switching to a 2bbl will almost always hurt gas mileage. Going to taller tires with a higher gear has you somewhere around the equivelant of a 2.73 gear. Your lugging your engine by having the rpms so low during cruise. Go back to the 4bbl and put some more gear in it. MId 2k rpms is where a small block likes to be. Lower rpms is not always better. If you were getting 14mpg with a 383 in a heavy truck you should have left it exactly how it was because that it real good mileage for one of these old pigs with the aerodynamics of a brick.

[383Chevy]

Originally Posted by cableguy0

You killed your mileage in the process of trying to find more. Switching to a 2bbl will almost always hurt gas mileage. Going to taller tires with a higher gear has you somewhere around the equivelant of a 2.73 gear. Your lugging your engine by having the rpms so low during cruise. Go back to the 4bbl and put some more gear in it. MId 2k rpms is where a small block likes to be. Lower rpms is not always better. If you were getting 14mpg with a 383 in a heavy truck you should have left it exactly how it was because that it real good mileage for one of these old pigs with the aerodynamics of a brick.

Prolly gonna hook the 4 back up tomorrow and find me some 3.73's