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4:09 axle

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  • #16
    For what it may be worth...

    I drive my stock (?) 259 Lark in the 3400 to 3800 rpm the better part of 160 miles (one way, four trips) at a crack. Twice a year.

    That said...it does take its tole.

    Exhaust valve seats, all valve springs (exhaust gets the worst of it).
    If the bearing clearances are good, no bearing damage should occure.

    OEM rods, pistons and pins if assembled correctly...should fair fine at that rpm.

    BUT..........will your ears and wallet?

    I put a set of 4.88's in my 56 Chevy (my only car!), with tall tires, lotsa years ago....
    I "voluntarily"....was driving 55mph on the freeway long...before the 55mph law originally went into effect !!!

    If it's "not" an everyday driver...and you don't go on long trips...you should be fine.
    My Conestoga will have similar gears out back (if!) when I get my 299 Stude engine done.

    Mike

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    • #17
      I don't get it Mike, why would you drive 1280 miles a year at 3800 RPM?
      That's gotta be a tanker truck of gas and a lot of wear and noise! [:0] Wouldn't it be prudent (and cheaper) to just install a 3.31? That must be a 4.56 ratio at 70/80 MPH! A 259 TRUCK might make sense, at least you could haul something!

      quote:Originally posted by Mike Van Veghten

      For what it may be worth...
      I drive my stock (?) 259 Lark in the 3400 to 3800 rpm the better part of 160 miles (one way, four trips) at a crack. Twice a year.
      StudeRich
      Studebakers Northwest
      Ferndale, WA
      StudeRich
      Second Generation Stude Driver,
      Proud '54 Starliner Owner

      Comment


      • #18
        So now, according to the calculator Dick posted, my 259/FOM with 3.31 rear and 225/70R15 tires will top out around 86 MPH at 3500 RPM. Does that sound right?


        [img=left]http://members.cox.net/clarknovak/lark.gif[/img=left]

        Clark in San Diego
        '63 F2/Lark Standard
        http://studeblogger.blogspot.com

        Clark in San Diego | '63 Standard (F2) "Barney" | http://studeblogger.blogspot.com

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        • #19
          I guess it depends on what you mean by "top out"? I always thought that meant the max it could do? But I know it will wind to 5500 and well over 100 MPH!

          StudeRich
          Studebakers Northwest
          Ferndale, WA
          StudeRich
          Second Generation Stude Driver,
          Proud '54 Starliner Owner

          Comment


          • #20
            Clark, according to my calculations, your Lark's engine should be turning in the neighborhood of 3,650 rpm at 86 mph with your tires and gearing setup (or 83mph@3500rpm). It appears whoever conceived the calculator Dick posted has forgotten to include slippage with a non-lock up torque converter. While the % slippage varies according to load, speed, etc, it never gets down to 0% unless it's of the lock up variety. Maybe the person who designed that calculator was a youngster (compared to most of us) and figured all automatics lock up.

            According to my calculations, a manual or DG tranny would be turning around 3,470rpm with your setup which jives with the other calculator. The rpm figures are approximate because I've measured enough tires to know that not all tires are created equal in height and width even though the numbers on the side are the same. And it's not always the cheap tires that are smaller. Right now I have a 245X75X16 Dunlop on my truck that measures 29 inches in diameter when mounted and inflated. It's too darned short and I'm replacing it with a Goodyear of the same posted size that measures slightly over 30 inches in diameter. In your case, a tire one inch taller would reduce your rpms by 100, so that's why I say the numbers are approximate. On my calculator, you can take your actual tire measurement and adjust the aspect ratio up or down until you get the tire's actual diameter for a more accurate figure. However (there always seems to be one of those in my posts, right?), any old style tires that are not belted will grow taller as their rotation speed increases and will reduce the engine rpms. If you've ever watched the big fat tires on the back of a rail at the dragstrip grow tall and skinny when the driver pours the coal to it, you get the idea.

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            • #21
              The 40.6 horsepower is taxable horsepower. In the good old days, when you bought a vehicle, your were taxed based upon the engine horsepower. The method of deriving the engine's taxable horsepower was a formula using the number of cylinders and cylinder bore in inches. For some unknown reason, the stroke wasn't included. Because of that wierd formula, the guys buying a car with a short stroke, large bore 250ci V8 payed more tax than someone buying a long stroke, narrow bore 250ci 6 cylinder. Most old titles will have the hp figure on there and Missouri still included that useless information on our titles even in recent years when we payed sales tax based upon the selling price. I don't know if they still do or not because I can't afford the price of a new car just to find out!

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              • #22
                StudeRich wrote -
                quote:I don't get it Mike, why would you drive 1280 miles a year at 3800 RPM?
                Well..
                1. Don't want to be on the road "all" day.
                2. For the most part, keeping up with the rest of the traffic.
                3. It gets really boring driving at 65mph for over two hours.
                4. Going to the drag races, don't want to miss anything!!!
                5. Cause...

                And no...tuned right, the milage isn't that much worse than doing the same trip at 70mph.

                The rest of the year...all the car does is putt around town!!
                Like a famous comedian once said..."Gotta burn it out once in a while, gotta get all the gunk out"!

                Mike

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