Motor options for USRA

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  • pig tracker
    Senior Member
    • Feb 2015
    • 104

    #1

    Motor options for USRA

    First off, I am not a motorman, hence my questions. Popped my motor and needing to get one built. We run an 8000 chip rule but I don't like twisting my motors that much-I run a 7600 chip. Would really like to run more like 7000 if it is possible to get dyno numbers right or if that is even possible. My last few motors have been very torque and I think I buzz my tires to much. I'm 68 years old and my right foot doesn't have the finesse like it use to. Was thinking about going with a little less torque and trying to get peak torque curve down closer to RPM that I want to run. Will this be possible and still be competitive or am I dreaming. Need some input. Thanks
  • let-r-eat
    Senior Member
    • May 2007
    • 2319

    #2
    How big are the tracks you run?
    BUCKLE UP NOW, YA HEAR?

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    • pig tracker
      Senior Member
      • Feb 2015
      • 104

      #3
      I run a flat 3/8 and a 5/16 high bank track. Does the cam grind and head work determine where sweet spot on curve is? Can you get same sweet spot on a 400 hp and a 650 hp motor? And if so, what are the drawbacks? Am I going to get killed on starts and restarts? Where on the track do you want to be at end of your pulling power range? Not sure either about a "crate type" motor. Ricky Thornton races with us sometime and he runs a crate in Tucson IMCA races but I was told he puts his USMTS motor in for our races.

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      • powerslide
        Senior Member
        • May 2007
        • 2696

        #4
        Stock 400 blocks are a ticking time bomb. Get a SHP block or do it in a 350 block.

        It really depends how stiff of competition you are running against on what you need. You are 68 and unless you have been racing all your life i don't think you are going to run with RTJ not trying to put you down lets just be realistic.

        If most everyone has the weight break and spoiler advantage from the spec you will need one as well to stand a chance. If i was going to do it all again new i would build the spec concept motor. You should be able to build a drivable 600hp motor that lasts.

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        • RaceMentally
          Senior Member
          • Nov 2013
          • 137

          #5
          Originally posted by powerslide View Post
          Stock 400 blocks are a ticking time bomb. Get a SHP block or do it in a 350 block. It really depends how stiff of competition you are running against on what you need. You are 68 and unless you have been racing all your life i don't think you are going to run with RTJ not trying to put you down lets just be realistic. If most everyone has the weight break and spoiler advantage from the spec you will need one as well to stand a chance. If i was going to do it all again new i would build the spec concept motor. You should be able to build a drivable 600hp motor that lasts.
          600hp hahahahahahha. You all still don't get it.
          When it seems all eyes are on you when you're wearing a new pair of jeans you wonder why everyone thinks you look so darn good in them. When taking them off you notice the sticker still on the pant leg.

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          • powerslide
            Senior Member
            • May 2007
            • 2696

            #6
            Originally posted by RaceMentally View Post
            600hp hahahahahahha. You all still don't get it.
            I'm sorry. Enlighten us oh great one since you do "get it".

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            • pig tracker
              Senior Member
              • Feb 2015
              • 104

              #7
              My reflexes are not the same as they were a few years ago. lol. The reason I brought up RTJ was he is the only one I know that runs a crate(apparently not with us) and I didn't want to have a knife at a gun fight. I can say, we have some XMods that run with our Amods and do pretty good when track is slick. I'm still having fun at my age, but I just destroyed my motor and was wanting to maybe try something different. And I also don't understand what RM was referring to either..

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              • RCJ
                Senior Member
                • Nov 2007
                • 509

                #8
                A 3.48/3.50 stroke crankshaft is smoother and more drive able than the longer strokes.Legal brodix spec heads make good power to around 7500 (been awhile since I had a legal head,best I remember).If your not wanting to spin it very high the flat tappet, stud rockers of the concept motor, with the spoiler and weight break, sounds good.

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                • mod88s
                  Senior Member
                  • Dec 2008
                  • 226

                  #9
                  I would go with a good 383. Nothing fancy. Since you want to run lower RPM's i would use the 3.75 stroke

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