Another reason to fly 2-cycle - OS 1.60's

[Bill Pritchett]

Eric:
Thanks for all the info and research that you so willingly pass along to all of us...... You've really got it going on..... except for one little thing.......
Go Colts!!

  ----- Original Message ----- 
  From: Henderson,Eric 
  To: discussion at nsrca.org 
  Sent: Monday, January 12, 2004 6:29 PM
  Subject: Another reason to fly 2-cycle - OS 1.60's


  (Jimbo, I wonder what the dB's are on that set up.??)

  In the absence of a rear exhaust 1.60 or 1.80 from OS many of us have turned to the 1.60 FX side exhaust. A stainless steel bearing is readily available, so fly and drain is the order of the day. It is also a big bearing and handles the prop loads very well.

  Most of you know that I have been running them along side YS L's DZ's Webra's,  Mintor 1.70s and OS 1,40's. I also have a couple of OS 1.60 FI versions that are trouble free. No injector issues so far. Many contests were flown with a Focus because the header fitted inside. Lately I flew my Temptation with the Mueller-special elbow exposed a la YS.

  The std OS 1.60FX uses exhaust pressure and I just could not bring myself to tap a hole, for a low pressure feed, in my CF pipes. Success was achieved with the Perry pump and in particular with the Cline regulator. Did need some extra plumbing and finger over the carb for 1st start of the day fuel draw.

  Through most of the end of 2003 I flew my OS 1.60's with an OS 1.40 pump fitted to the backplate. It was easily the easiest system to operate. Just like 1,40RX. There is no pressure in the tank which is personally preferable in hot weather conditions. The modification did require my Sherline mill and lathe. It is not just a simple case of machining the out the backplate. A 1/8" stand-off ring is required and some judicious 2.5 tapping.

  The engine ran just like the FI but I would have liked a slightly richer top end without fattening the carb too much in the mid range. The engine never faltered, but it used more fuel when set the that way. The 1.60 FI lets you tune the middle and top end. The 1.40 RX carb will fit the 1.60FX and is reported to do better. I think that I will go the way of Jeff Carrish and Earl Vincent. They fitted OS MC carbs to their planes. It is so much more effective to set seven points on a 10X.

  From a weight point of view you save weight using this integral pump versus the FI electronics module and wiring etc. You can also save 1-2 oz on the prop driver and the prop washer. (Sherline again). I could save more if I could drill and tap the prop-shaft for the spinner nut. This gets the engine close to the DZ in weight. In the power dept., most of the engines mentioned above will be good up to a 17 x 12, The OS 1.60 can handle the 17 x 13 and is very quiet. Less than 90 db over hardtop.

  This season will be 2-c's for me unless of course there is a YS 1.60 DZ. They only thing that could draw me a way from this plane would be a YS 1.80 rear exhaust  

  Go Pat's and Eagles,,,,

  Eric.

  P.S. The twin plug head OS 1.60 FX experimental version was a pain. It ate the OS "F" plugs and many A3's and A 5's. Was just a reliable and idled slow with one F. I use it now with one dead plug.  

  P.P.S. There is a website out there in Sweden, I think, who also has done this. Mounts his engine sideways> Uses a  more regular header etc. Pretty neat set-up in a German Rhapsody.

  -----Original Message-----
  From: discussion-request at nsrca.org [mailto:discussion-request at nsrca.org]On Behalf Of Woodward James R Civ 412 TW/DRP
  Sent: Monday, January 12, 2004 5:46 PM
  To: discussion at nsrca.org
  Subject: Another reason to fly 2-cycle


  OS 160 users, checkout this setup for $95.00!!!!  http://www.ohiomodelplanes.com/acc/

  I called and John said that it is "feather-weight."

  Jim W.




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