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  • #16
    14x7 -

    "Polish the counter weights, while "they're" at it"........?
    I'm all for freeing up power...but what does polishing the counter weights do?

    Mike

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    • #17
      I think this is what he means by polishing the counterweights:

      http://www.enginebuildermag.com/Arti...th_enough.aspx

      Basically it takes the pits and rough spots out of the crankshaft and prevents the lube from settling into these areas. Apparently it increases the life of the crankshaft, which I find interesting as my own engine has had only a single rebuild since leaving the factory in '63(Just food for thought). It also looks like its part of a build that has tolerances that are less than the thickness of a piece of paper as well. If you're going blank to the wall, building a engine that will spend its life above 3000 rpm, or want that high quality, high end build in the engine bay, it sounds like a good idea.

      [img=left]http://i158.photobucket.com/albums/t102/PlainBrownR2/My%201950%202r5%20Studebaker%20Pickup%20with%20turbocharger/P1000137-1.jpg[/img=left][img=left]http://i158.photobucket.com/albums/t102/PlainBrownR2/My%201950%202r5%20Studebaker%20Pickup%20with%20turbocharger/P1000145-1.jpg[/img=left][IMG=right]http://i158.photobucket.com/albums/t102/PlainBrownR2/Ex%20Studebaker%20Plant%20Locomotive/P1000578-1.jpg[/IMG=right]
      [IMG=right]http://i158.photobucket.com/albums/t102/PlainBrownR2/My%201964%20Studebaker%20Commander%20R2/P1010168.jpg[/IMG=right]

      1964 Studebaker Commander R2 clone
      1963 Studebaker Daytona Hardtop with no engine or transmission
      1950 Studebaker 2R5 w/170 six cylinder and 3spd OD
      1955 Studebaker Commander Hardtop w/289 and 3spd OD and Megasquirt port fuel injection(among other things)

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      • #18
        That giant "book" of text says nothing more than after grinding the crank journals, cam bearing surfaces and cam lobes you need to micro-polish them. Nothing about the counterweights. That guy must get paid by the word! Lol!
        StudeRich
        Second Generation Stude Driver,
        Proud '54 Starliner Owner

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        • #19
          Hey, I'd rather have great detail on matters like these, than little detail and have them leave out something detrimentally important..... [}]

          Okayyy, it doesn't say much on polishing counterweights, that's a new one over me. But I remember when hanging around with the import guys that you can knife edge a crankshaft, like these guys:

          http://www.turbomagazine.com/tech/06...ice/index.html

          What happens here is you're removing mass from the crank and getting better performance from the engine(quicker acceleration), as well as taking some of the windage out of the crank. But like before, if you're doing this, odds are you probably have other things in mind than a run of the mill rebuild.
          1964 Studebaker Commander R2 clone
          1963 Studebaker Daytona Hardtop with no engine or transmission
          1950 Studebaker 2R5 w/170 six cylinder and 3spd OD
          1955 Studebaker Commander Hardtop w/289 and 3spd OD and Megasquirt port fuel injection(among other things)

          Comment


          • #20
            At the end this article covers "directional" polishing.
            It is important, especially for tuftrided, nitrided, or the various flavors of cast crankshafts.

            http://www.enginebuildermag.com/Arti...th_enough.aspx

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            • #21
              That article ,on cross directional ,doesn't really mention counterweight polishing. You know when I went to the speed shop to pick-up my 327 crank ,I was just surprize ,and in awe that the counter weights were polish. I'm really surprized that more people don't really consider this, that word has not got out about this. Some owners are not really into the rebuild of the engine. I remember the one guy saying have the engine balance, but I didn't ,not thinking what credit this could bring.

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              • #22
                FWIW, most of the cited links were about polishing the bearing journals of the crankshaft. This is a good thing and standard procedure in any reputable automotive machine shop.

                However, polishing the counterweights on a Studebaker V8 is another thing entirely - it would not add [u]any</u> measurable horsepower. Most of the experienced drag and round-track race engine builders I know have crankshafts lightened to reduce the rotating inertia. A lighter rotating/reciprocating assembly - pistons, rods, crankshaft and flywheel, will accelerate more quickly than will heavier parts. It doesn't make any more horsepower, just like a lighter car doesn't make any more horsepower, but will accelerate faster than will a heavy car. What polishing they do on the counterweights is mainly to clean up the machining/grinding marks from the lightening process.

                Some builders feel, but have difficulty proving, grinding the counterweight leading edge to a knife point reduces oil windage in the crankcase. I've never seen any reliable dyno evidence it does, or that it makes any more horsepower. Probably doesn't hurt to grind to that profile while lightening the crank, but modern synthetic oils are so thin, they don't wrap around the crankshaft as did old 50w. Pennsylvania crude and dry sump pumps keep the pan dry anyway, so there is little oil for a race crank to hit.

                Bottom line, polishing the counterweights of a stock or mildly modified Studebaker crankshaft would most likely be a waste of abrasives and labor. Maybe on Jim Lange's Bonneville engine, it might have some marginal benefit, but since he already has a dry sump, it's doubtful even there.

                thnx, jack vines

                PackardV8
                PackardV8

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