O.S. 55AX on Q500
 

I'm wondering if anyone has tried the O.S. 55AX on a Q500 airframe. It's lighter than most .46 engines and I bet it would give a nice boost in speed.
http://www2.towerhobbies.com/cgi-bin...?&I=LXNMD1&P=0

RE: O.S. 55AX on Q500
 

The O.S 55AX is better at pulling large props at lower rpms. Great fo 3D & sport, but it's the last engine I'd put on a viper. As for O.S.'s line up for a viper (#1) 50fx (#2) 46fx (#3) 46ax.

RE: O.S. 55AX on Q500
 

The Thunder Tiger 46 pro with Ultra Thrust or Jett muffler is a great bang for the buck. If you need something more, try a Webra 55 (it's lighter than most 46's) with a Jett muffler, Fox standard long glow plug on 15% turning an APC 9x10 at 16,300, but in 3 minutes the fuel is near gone, so set up for landing. Here are two 55's in the appropriate rides. The Webra in a Viper and an O.S in a Tiger II.

RE: O.S. 55AX on Q500
 

I've had quite a bit of experience with both the OS. .46 FX and OS. 46 AX, and without a doubt, the AX is a stronger motor on a quickie airframe. When I say stronger, I am not saying more RPM, as it does like bigger, lower pitched props. It is very happy with a sport APC 10x7 turning 14,200 rpm on the ground. The .46 FX liked higher REVS, like a 8 3/4" x 8.75 turning 16,500. Top Speed with either motor is very close to being equal, but the AX pulls through the turns without loosing nearly as much speed.

Not sure about the .55 AX, I've not heard a lot of good things about it, but it may just like a different prop than what others have tried, I would think a 10x8 might work well, as you won't have ground clearance for anything larger than 10".

RE: O.S. 55AX on Q500
 

Jeff....

the 55AX is just not designed to be an rpm engine. Would take some innovation and testing with prop selection to find speed on a quickie.

If you have one ...... use it... my guess is that with a 8.8x9.25 up front you might find the right engine load and power match.

If you are looking at buying an engine.....

The other engines mentioned are much better suited.

I tend to prefer the TT46pro and jett-stream combo as a good econo-speed setup. Even with the stock muffler, the TT46 with a 9x7 is good for 120mph+ in level flight on a Q-500 airframe. For most, it would be the fastest thing they have flown.

The OS46AX is described well by DaveN. That is a bit of a different animal, but with the right setup and prop selection it can indeed work well for speed.

Bob

RE: O.S. 55AX on Q500
 

i am no expert but here is what I know. i have a well used 55ax we started playing with. We strapped it to a golgberg hot stik 40 with a tuned pipe made for an os46. i am not sure of the brand as it was a friends pipe but it was turning an apc 12x7 at 15400 with 30% fuel. Hope this helps.

RE: O.S. 55AX on Q500
 

You mean a 10x7, right?

RE: O.S. 55AX on Q500
 

If that motor can turn a 12-7 at 15,400, I'll take ten right away!

MJD

RE: O.S. 55AX on Q500
 

If you're looking to buy a motor. My vote is for the TT40 or .46. My .40 is pinching up to 16,900 on a standard C-2 9x6 Bone stock (recommended by Bob27). The plane is fast! These motors run great and allow for a great boost with a Jett pipe. Cheap combo's

RE: O.S. 55AX on Q500
 

I bought a GP viper 500 and put my OS 55AX on it. It was what I had on hand (Jett 50 ordered for it). Like previously stated the 55 likes bigger props. I had a 10X6 on it (grass mower due to short landing gear) went to a 9x8 and now using a 9x9 APC. It turns 15,100 RPM and the ground running 15% nitro and a stock muffler. I have no idea of how fast it goes but it really scoots, great excelleration even going stright up. The only problem is that the engine dosen't idle low enough with the 9x9 prop to make the low drag air frame slow down enough to land with out a long, long, approach, it just keeps on going and going and going. Prop RPM combo may be bad for the engine. I'm new to this sport so what would I know?

RE: O.S. 55AX on Q500
 

I always land the Viper "dead stick". With the plane slowed down to idle, I kill the engine about 300' from the end of the runway. Try a 9 X 10 apc.
The OS 55 AX on a stock muffler&baffle is one the best idling engines made, but you would still need a 7000' runway to land the Viper engine on.:)