Mintor Review

[JOddino]

A long pipe flattens the torque curve and that is what we want.  We want more torque at lower rpm.  If you were racing and had a constant load you would tune for maximum rpm, but in aerobatics when you  pull vertical the engine slows down.  It won't slow as much if you have increased the torque at the lower rpm.  Make sense?
Back in the 70s Pete Callas figured this out and while many guys had more rpm on the ground, their engines didn't pull like Pete's.  Chip picked up on this and probably got more credit than Pete for going to the long pipe.
Jim
  ----- Original Message ----- 
  From: jghughes 
  To: discussion at nsrca.org 
  Sent: Thursday, April 01, 2004 6:14 PM
  Subject: Re: Mintor Review


  I normally agree with you guys on 2 stroke tuning, but as we lengthen the pipe to get a smoother transition, what is really happening is you are bringing the "resonance" rpm down and giving up top end power. If you go to Ed Hartley's two stroke page, You will see that there is not a lot of difference in rpm between the muffled OS1.40's and the tuned pipe ones. I agree that if you have an engine ported for a pipe and all's you care about is top end, a pipe makes a huge difference. But we care more about throttleability on these engines, so the HP is down. I'll loan one of you guys my 590 and you can test back to back if you want.

    ----- Original Message ----- 
    From: Dean Pappas 
    To: discussion at nsrca.org 
    Sent: Thursday, April 01, 2004 12:41 PM
    Subject: RE: Mintor Review


    Karl's right.
        Dean
      -----Original Message-----
      From: Karl G. Mueller [mailto:kgamueller at rogers.com]
      Sent: Thursday, April 01, 2004 3:37 PM
      To: discussion at nsrca.org
      Subject: Re: Mintor Review


      Steve,

      With proper exhaust port timing and setup with a good pipe you will
      loose that bet. My bet is that you will gain closer to 20% improvement
      in power, of course with more power comes a higher fuel consumption
      as well. Most engines are very conservatively ported in the exhaust
      timing to run on a muffler as well as on a pipe. Just an other compromise
      by the manufacturers.

      Karl G. Mueller
      kgamueller at rogers.com
           
        ----- Original Message ----- 
        From: Patternrules at aol.com 
        To: discussion at nsrca.org 
        Sent: Thursday, April 01, 2004 9:49 AM
        Subject: Re: Mintor Review


        In a message dated 4/1/2004 9:28:50 AM US Eastern Standard Time, d.pappas at kodeos.com writes:
          Mintor 140 article, how does it run on a muffler as
          opposed to a pipe. I would expect some loss in power
          but also a loss in cost.
         I don't use pipes on any on mine engines Jeff Hughes and I have been using the Bolly 590r which is a muffler, no tuning head aches, no midrange problems, if you change props, fuel or anything else NON PROBLEMS, I have been running the Mintor 140 with it and it runs super, don't know how much less power you get from just running a muffler but I'd bet it's not over 5%, I use Coolpower 15% fuel.


        Steve Maxwell
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