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Looking to get into a '49 3100

Discussion in 'The Hokey Ass Message Board' started by rivera, Dec 6, 2009.

  1. rivera
    Joined: Oct 5, 2009
    Posts: 57

    rivera
    Member
    from Ogden, UT

    Hey guys, I've been bit by the classic truck bug and I've got a few questions. What's the story with leaded vs unleaded gasoline on cars this old? Am I gonna have to use an additive every time I fill up? I found a truck near me for a pretty good price and its all original. Surface rust here and there but to my knowledge its not rusted through anywhere. The engine turns over but it doesn't run, and it needs a new clutch. I'm thinking about making this a daily driver. My only concern is the gas mileage, I know these cars weren't built for that in mind but I'd like to get upwards of 17-20 mpg and I want to know if its possible and what these inline 6's get stock. Also, its a three speed iirc, is it possible to cruise on the freeway at 70 mph with this transmission? Any help from you guys is very much appreciated. I found this site through the jockey journal and so far I've seen a lot of cool shit. Here are some pics of the 3100..

    [​IMG]

    [​IMG]

    [​IMG]

    and the '70 Triumph for kicks...

    [​IMG]
     
  2. adam401
    Joined: Dec 27, 2007
    Posts: 2,857

    adam401
    Member

    That bike is absolutely beautiful:eek:
     
  3. hotrod-Linkin
    Joined: Feb 7, 2007
    Posts: 3,382

    hotrod-Linkin
    Member

    gas mileage and hotrodding .....you compensate by gearing it to an acceptable level. or just gas and go and gas.
    as for unleaded gas...just fill er up and have fun.

    70 mph..see first answer above. i think landons or patricks has a ring and pinion for the stock housing.
     
  4. OldSub
    Joined: Aug 27, 2003
    Posts: 1,064

    OldSub
    Member Emeritus

    A '49 with a floor shift is a 4-speed.

    Most people run unleaded in these old motors with no problems.

    Going 70 and getting 20.... Both those are more difficult.

    That's one of the babbit bearing type motors and they make a lot of racket turning fast enough to go 60. There is a ring and pinion kit available that changes the rear gears to 3.35 which helps.

    If it were me I'd take a different approach. I'd change the rear axle to open drive and gears in the 3.7 or 3.5 range, swap in a T-5 transmission to get overdrive and give the motor the best tune-up possible.

    Only in great tune will it deliver mileage approaching your target. And only with a change in gears will it go 70 and produce any reasonable mileage figures.

    I've gotten as good as 17 mpg from my similar Suburban running the freeway at 70. I have a GMC 270 motor with the same 4-speed as the truck in the picture, and 3.08 gears. Mine is not optimized for mpg, but does okay. Your motor is smaller and you may not be satisfied with the gearing that works for me.

    That's my two cents...
     

  5. rivera
    Joined: Oct 5, 2009
    Posts: 57

    rivera
    Member
    from Ogden, UT

    Thanks for the input guys. Figured gearing would be something I'd have to play with.. Any idea what the mpg is for the original straight six?
     
  6. al-uminum
    Joined: Nov 19, 2008
    Posts: 55

    al-uminum
    Member

  7. I had the exact same drivetrain in my truck when I got started. The fastest I felt comfortable going was a little over 50. And at that speed my eardrums were touching together from listening to the worn out babbit pounder screaming thru the 4.11 gears. Now, with a rebuilt .060" over 261, a .72 overdrive T5 trans and 3.42 geared rear axle 70MPH seems like the motor is just beginning to clear its throat. I only recently started keeping track of gas milage and the best I'm getting is about 16MPG.
     
  8. I've seen the truck, and you can't go wrong for the price. Does it still come with the other truck too? Don't worry about gas milage - buy it!!!

    Oh, and welcome from another UT HAMBer.
     
  9. Gator
    Joined: Dec 29, 2005
    Posts: 4,016

    Gator
    Member

    15 mpg is a more reasonable expectation. I think the only way you're gonna get near 20 is with an overdrive setup. I had the virtually the same truck you've got there and a '53 Ford F100 with a 6 cyl/3 speed combo, both were bone stock and both got about 15-16 around town and worse on the highway.
     
  10. ...if your truck has a 3 speed, it's a 47 or 48, as that was the last years for floor shift with the 3 speeds, does the gas fill thru the bedside on pass. side?, if so, that's nother 47-8 trait (gas tank under bed).
    Also 47-8's had the smooth firewall like yours (no ribs stamped beside the fuse box or next to the heater. Fuse boxes were also a 47-8 thing I believe.
    ...you got a really nice truck there and the Triumph is awesome, is that a 500?
     
  11. rivera
    Joined: Oct 5, 2009
    Posts: 57

    rivera
    Member
    from Ogden, UT

    thanks for all the input guys. considering how much i drive and the gas mileage i'll be looking at, i'm leaning away from getting this project. it really is a good deal and i'm really tempted but i'd be filling up twice a week driving this thing which would cost a lot of money. i'm still thinking about it, maybe doing some mods that will help get me some decent mpgs. hopefully you guys can point me in the right direction! as for the triumph its a 650. thanks for the compliments!
     
  12. OldSub
    Joined: Aug 27, 2003
    Posts: 1,064

    OldSub
    Member Emeritus

    Actually '48 was the first year for the SM420 floor shift 4-speed that was used through '67 and the first year for the column shifted 3-speed in the trucks.

    The floor shift 3-speed was last used in '47. It has a release lever to allow shifting into reverse and no synchros.
     
  13. midnight auto parts
    Joined: Feb 1, 2007
    Posts: 59

    midnight auto parts
    Member
    from tn

    nice looking truck, would love to find one near me that nice. do the rear end 3,55 re-gear and drive her. it,s a nice peaceful drive in these ole chevys and lots of new people to talk to ever time you park some where.
     
  14. rivera
    Joined: Oct 5, 2009
    Posts: 57

    rivera
    Member
    from Ogden, UT

    What are my options for a good (and cheap) engine/trans swap that would get me decent power and good gas mileage?
     

  15. 235 or 250 with a o/d trans T-5 or 200r4 or 700r4 and a rear with 3:42 gears will give you 20+mpg. Todd
     
  16. OldSub
    Joined: Aug 27, 2003
    Posts: 1,064

    OldSub
    Member Emeritus

    I have a '91 3/4-ton Chevy four-wheel-drive with a 350 and a 700r4 that gets 17 mpg on the highway. I'm sure my '91 weighs more than a 1,000 pounds more than the '49, plus its pushing a bigger profile into the wind. The same engine/trans with similar gears would likely get close to 20 in that '49.

    I don't think you can beat a TBI small block with an overdrive automatic for all around drivability and economy in something like that truck. Yes you can go with a smaller motor, but the gains are minimal and you loose performance.

    Cheap is a relative thing. Pickups like the one I have are out there for sale pretty cheap these days, maybe cheap enough to part one out to get the motor and trans.

    A TBI small block isn't traditional so you'll need to hide it under an old Cadillac or Olds air cleaner!
     
  17. rivera
    Joined: Oct 5, 2009
    Posts: 57

    rivera
    Member
    from Ogden, UT

    You guys really got me thinking about doing this now... How easy would a 235 or 250 drop in? Is it a relatively common swap?
     
  18. OldSub
    Joined: Aug 27, 2003
    Posts: 1,064

    OldSub
    Member Emeritus

    The 235 from a '54 pickup is a simple swap. Any 235/261 Chevy or 270/302 GMC will go in with few modifications.

    The 250/292 swap is more involved. First you have to change bellhousings if you are using an manual trans. There are bellhousings that are close, but modifications are required to use any of them.

    Then you have to create side-mounts for the motor. For the 250 you can use a V-8 swap type crossmember, but the 292 will require fabrication because the mounts are staggered.

    The 235 swap is probably the most common and V-8 swaps are probably more common than all the other options combined.

    My two cents... A mild 250 with an overdrive transmission (think T-5) might come close to your mileage target. None of the other sixes will do so easily.
     
    Last edited: Dec 8, 2009
  19. rivera
    Joined: Oct 5, 2009
    Posts: 57

    rivera
    Member
    from Ogden, UT

    Well, I went from really wanting the truck, to not so much, then not at all, to wanting it again! Lots of ideas floating around. I forgot to mention it comes with a '54 parts truck which is complete minus the drivetrain. I may still purchase the trucks and sell the '49 and complete the '54 with the extra dough and get the gas mileage good enough for a daily! We'll see. All said and done I still can't look at the car until Friday and it could very well be sold by then. If it was meant for me to have it I suppose I'll get it. You guys have been a great help. And I'll be asking for more info if I do said plans. I'll keep you guys posted!
     
  20. rivera
    Joined: Oct 5, 2009
    Posts: 57

    rivera
    Member
    from Ogden, UT

  21. HEATHEN
    Joined: Nov 22, 2005
    Posts: 8,582

    HEATHEN
    Member
    from SIDNEY, NY


    You may want to remove that gray, football shaped hood ornament; it doesn't look very aerodynamic. Believe it or not, a well set up dual carb intake will get you better mpg than the stock setup.
     

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