ORIGINAL: rotccapt
well i got it reinstalled on the plane after making my new carb spacer and i got some static thrust numbers. i am getting 8.2 lbs of thrust off my current setup. i know this engine can do better and i dont realy feal comfortable flying an 11 lb plane with 8 lbs of thrust i know i would be ok, but i like to have get outa trouble power and at those numbers i dont have it. so i decided to order a wt-456-1 to see if i get a bit more performance out of the engine. i know that when i ran the glow carb i was getting 8600rpm so right now i am almost 1000 rpm slow. so hopefully i can get my power back.
pullup can you post a pic of your counter spring that you installed to help the servo? also would it be possible to use the throttle shaft that is on my wt-340 in the 456? i ask this because i soldered a ball link to the throttle arm to attach my linkage to and it would be nice to re use it. i know i can just de solder it but if that is not required it would be nice. other than this my plane is ready to fly
Here's a belated response to ROTCCAPT's request for a picture of the Stearman with it's Saito 150 (WT456-1) gas conversion showing the throttle helper spring to counteract the constant servo pulling by the accelerator pump spring. Sharp folks out there will figure out this is a compromise at best because at idle, the accelerator pump spring is more relaxed just when the helper spring's force it at it's maximum. Likewise, when the throttle is a full and the accelerator pump spring is at maximum force, the helper spring is unfortunately relaxed. HOWEVER, I fly at mid throttle a lot with this powerful setup, so at that point there is benefit to the servo.