[Votec Yak Guy]

I've been flying the crap out of my Votec lately with a 157CS and Biela 3D prop (31.5x14x8....virtual 3W 3D prop knock-off). Granted the airframes are different (Votec vs Yak), and my 157CS is fully broken in (probably 50 gallons through it), while the 170CS has only run 7 gallons through it, but both motors are equipped as follows:

same prop - Biela 3D
same oil - redline at 40:1
3W canisters - L90's for the 157CS and L90K's for the 170CS
both have light CF spinners - 6" for the 157CS and 5" for the 170CS
same carbs - Tillotson MP4's
same flying field elevation and atmospheric conditions


I think the 157CS has more power and torque as my 170CS in my Yak.

Anyone else having similar comparisons?

Greg

[Showtime]

Yes i have compared both planes with the same engine set up you have. I also had a 3w yak with a 157cs in it so i have that to compare also, Bottom line
157 is a power house. It runs smoother than the 170. Over all power I would still say the 170 has a little more grunt than the 157. The votec has such a slippery air foil compared to the yak.

So here is what i have come up with . If you have a Little on the heavy side air frame go with the 170. But if your plane is light and has good lines a 157 is more than you will ever need.

I still have 2 157 and 2- 170 and would not change them for the world.

[Votec Yak Guy]

Hey ST, I've had 2 157CS and 2 170CS's. Both of my 157CS's ran/run very smooth. My first 170CS (one of the first production runs) shook really bad, particularly at idle. My current 170CS runs as smooth as my 157CS's.

[Mithrandir]

Someone told me all the 3W 40% planes have the same wing....

Greg.... other then the root trim... compare the Votec wing to your Yak wing and let me know if they look the same!!!

[Votec Yak Guy]

Originally Posted by Mithrandir

Someone told me all the 3W 40% planes have the same wing....

Greg.... other then the root trim... compare the Votec wing to your Yak wing and let me know if they look the same!!!

My Yak wings have:

Thicker trailing edges (~5/16" vs 3/16")
Slightly reduced tip cord (more wing sweep leading and trailing edge - I can measure if you want?)
Bigger ailerons (I can measure if you want)
The airfoil appears to be identical....

Greg