o.s. 160 question

[Alan Hewson]

I am also running a Perry pump.
I found that after approx. ten flights that it suddenly started pumping more fuel. I then leaned out the pump about 1/12 of a turn and everything was fine again.
I think that possibly the Perry pump has a "break-in" period......don't know why, but just my observations.
And BTW, it draws fuel from 3 fuel tank plumbed in series.....no problem.
Alan Hewson


  ----- Original Message ----- 
  From: Bob Pastorello 
  To: discussion at nsrca.org 
  Sent: Sunday, June 20, 2004 10:52 PM
  Subject: Re: o.s. 160 question


  I can only share my "cookbook", the results of ideas/suggestions from many people...Gene Maurice, Matt Kebajian, Dave and Ron Lockhart, and many others...but...the OS 1.60 is ABSOLUTELY viable, and reliable...detailed info is on my website, but here's the short version.
      1.  15% fuel, synthetic is best
      2.  OS 8 or A5 plug (A5 gives better midrange, and a little bit on the top end)
      3.  Perry Pump, VP-30, using crankcase pressure from a backplate tap.  Mounted on the firewall.  Adjusted about 1/2 turn leaner than from factory, but adjust for optimal midrange on the ground.
      4.  "Wave Length" of the the tuned setup - I've now used 4 different kinds of pipes, and the "ball park", for 8000-8100 is about 24.5 inches, plug center, following header, down pipe to the reflector baffle.  On conventional pipes.  The Mac's 1092, a great setup, needs to be at 22 1/2, measured the same way, but it uses rings instead of baffles.
      5.  Current setup is the best I have - OS 1.60, Cool Power 15%, A5 plug, Mueller header, AeroSlave Pre-production CF pipe, VP 30 pump, APC 15.75 x 12 (Lockhart Re-twist), turning about 8100, pipe is at 24.5", plug to baffle (following curve of header length)  Needle is open One Turn + 2 clicks richer from closed.  Will idle all day, transitions linearly, doesn't load up, and has beau coup power....LOTS...(ask anyone at KC this weekend!!!)
      ** NO ** midrange problems.

  Feel free to email direct for more info...

  Bob Pastorello
  rcaerobob at cox.net
  www.rcaerobats.net


    ----- Original Message ----- 
    From: JonLowe at aol.com 
    To: discussion at nsrca.org ; flyintexan at houston.rr.com 
    Sent: Sunday, June 20, 2004 9:22 PM
    Subject: Re: o.s. 160 question


    In a message dated 6/19/2004 8:04:34 PM Central Daylight Time, flyintexan at houston.rr.com writes:
      I am running the OS in intermediate as well.  I used the iron bay with some
      success, until it locked open during a sequence, flooding out the motor.  My
      setup with the regulator and greve pipe always ran rich in the midrange.  It
      got better when I lengthened the pipe, but not perfect.  With that setup it
      flew the outside loop o.k., but I always throttled up just before the very
      bottom of the loop.  As it would come up through mid range, a bit of smoke,
      maybe a cough, and away we go.
    Thanks for the info.  I too am running a Greve.  I've tried an Iron Bay regulator with a Cline one way valve after the IB vavel failed, am unsatisfied with the midrange, and am ready to go to the Perry pump. What is the length you are running on your Greve, from the glowplug, around the header, to the end of the main body of the pipe?  What prop?  I have no one around me running a similar setup, so I'm looking for a "cookbook" formula that works.

    Thanks.

    Jon Lowe
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