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Gas mileage

Discussion in '1983-2005 S-Series models' started by kennyw, May 22, 2003.

  1. kennyw

    kennyw N9PHW Premium Member

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    I once had a 1985 GMC S-Jimmy 4x4. Originally had a 2.8L (carb), 700R4 and got about 15 mpg because the motor was too weak to hold the truck in overdrive driving down the freeway. After swapping in a mild 350 V8 (4bbl carb) w/ 700R4 I started getting 18-20 mpg.

    So now I have a 1986 Chevy S10 2wd. It now has a tired 2.8L (TBI), 5 spd and 4.10 gears in the rear axle (according to option codes in glove box). I am now getting 22.5-24 mpg out of it and just started plotting... Anyone have an idea what kind of gas mileage a TBI 350 V8 would get in a 3000# truck if I keep the OD 5 spd?
     
  2. big83chevy4x4

    big83chevy4x4 3/4 ton status

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    i would guess about 20-22 mpg. if you want to keep the 5 original 5 speed, i have the 10.5" clutch disc that advance adapters sells.
     
  3. kennyw

    kennyw N9PHW Premium Member

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    I guess I had better take a look at all the parts needed to do this conversion first...

    Motor
    Motor mounts
    V8 Bellhousing
    radiator
    Clutch (V8 pressure plate or V6 pressure plate?)
    Computer??
    Headers
    Short water pump, flex fan and dual 12" electric pusher fans (I know they will fit behind the grill)
    V8 P/S brackets

    What else?
     
  4. big83chevy4x4

    big83chevy4x4 3/4 ton status

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    only one thing that i see that you missed.
    JTR swap manual, (there is a lot of fire wall modification that you need to do with a BFH /forums/images/graemlins/smirk.gif that they show you)

    if you run the shorty headers, they will not work with the camaro bellhousing. you will need a bellhousing off a 88-92 fullsize chevy truck and have a pilot ring machined to center the trans in the bellhousing.

    the pressure plate you could get out of a camaro with a 10.5 clutch.

    there is a lot to do to swap a sbc in an s10. alot more than i thought i would deffinatly sugest getting the manual, because they go through everything step by step.

    i don't have my manual handy, but if you have any questions just throw my a pm or something.

    Thanks TJ
     
  5. kennyw

    kennyw N9PHW Premium Member

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    [ QUOTE ]
    there is a lot to do to swap a sbc in an s10. alot more than i thought i would deffinatly sugest getting the manual, because they go through everything step by step.

    [/ QUOTE ]
    I understand that very well, I have actually done this swap once before on a 4x4 S-series Jimmy. Took me about a year and $1000 more than I originally planned plus a lot of trips to the wrecking yard searching for parts (this was before I had internet access to find this stuff out easily /forums/images/graemlins/rotfl.gif). I tried buying that book the last time but it was back-ordered everywhere I tried to buy it at the time.

    Right now I am just kicking around the idea as I know it would be more work than I have time for unless the truck was to blow up (300,000+ miles on the original motor and tranny so far). But it would be fun to drive an S10 with V8, 5 spd and dually conversion to make the longbed look better...
     
  6. Diesel Dan

    Diesel Dan 1/2 ton status

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    [ QUOTE ]

    So now I have a 1986 Chevy S10 2wd. It now has a tired 2.8L

    [/ QUOTE ]

    I installed a 350 into a '83 S-blazer, 2wd. Easy swap. Bought the motor mounts from Jegs, stock pan clears. Had a '83 Z-28 for donor parts, used the exhaust manifolds and 700R4 from the Z, no expensive headers required. IIRC, short water pump and electric fan was nec with stock radiator location.

    Never drove it, lost interest after I found the 6.2 diesel wouldn't fit /forums/images/graemlins/eek.gif. The 2WD's are alot easier and cheaper to convert than the 4x4s.
     
  7. MEPR

    MEPR 1/2 ton status

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    something you might try is to get a 2.2L isuzu deisel that they put in luvs and pups. They are hard to find but if you get one a luv whith that bad boy will 40-45mpg. Im guessing an s-10 whith that mottor would atleast get high30s for millage. /forums/images/graemlins/eek.gif
    oh but power will be rather unimpressive, 95lbsft at 1200rpm and 90hp at 2500rpm... /forums/images/graemlins/tongue.gif
     
  8. Diesel Dan

    Diesel Dan 1/2 ton status

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    Or just find a factory 4cyl diesel S-10. I've seen a few for sale.
     
  9. Seventy4Blazer

    Seventy4Blazer 3/4 ton status

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    [ QUOTE ]
    Or just find a factory 4cyl diesel S-10. I've seen a few for sale.

    [/ QUOTE ]
    same motor as the pup.
    Grant
     

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