Considering replacing my Align 700N nitro engine with a gasoline engine, is there a gasoline engine for this?
Would this be a good idea?
What are the performance difference in 3D flying comparing the gasoline and nitro engines?

OS has come out with the OS15GTHZ gasoline engines for helicopters but from different gasser forums, it seems to have had a lot of teething problems. A flying mate had fought with one over the summer in his JR SG700. After sending it back to OS in Japan three times he finally gave up on it an got himself a Century Radikal G-30V2FBL with the HWC/Zenoah motor and is very happy with it.

Becides the OS, there is no other gasoline engine to replace with?

If I want to go with a gasoline heli, below $2,000, what would you guys recommand?

Another popular option is to get the HWC conversion for your T700N from Century Helicopters.

http://www.centuryheli.com/products/...tml?pageid=755

and mount one of these HWC tuned Zenoah engines:

http://www.centuryheli.com/products/...tml?pageid=348

But if it were me, I would sell the T700N and get a true 700 class gasser like the Century Radikal G30/V2 with one of the engines above - probably the 29 if you are into 3D and if not then the G231 Expert.

http://www.centuryheli.com/products/...tml?pageid=287

good idea, sell the nitro and buy the gasser.

I agree, sell the T700 and get the Radikal. I love both my Radikal 20 and Radikal 30.

Avoid the GT15, very problematic. There are 3 gas conversions for the 700n, HWC, helibug and HelixHeli. Im looking at ahelixheli myself for a second gas heli (already have a MinAir)

Zenoahs are very reliable, reccomend you look at a tuned motor from Hanson or ToxicAl.

I found the HWC tuned Zenoah G-20 engine more powerful and much smoother then the stock Zenoah on my Century Radikal G20. The EI unit that comes with the stock Zenoah took more then twice the battery power then did the one that came with the HWC.

how is the reputation of HWC? currently I'm living in overseas, I can only ask them to ship to me.

So far, I know of a few others that have them in different sizes, and all are very happy with them. Seeing this video when it was posted on HeliFreaks is what spurred me to try one.

http://www.centuryheli.com/products/...tml?pageid=287

That is the bigger G30 with the HWC modified G29 Zenoah engine and it looked to be a real great power system. So I thought I would try their smaller G20 version on my smaller Radikal G-20.

I converted my T-Rex 600 for gasser, I'm using zenoah RC 270. You should use the RC 290. Avoid the OS engine, it's problematic.

I will go with the HWC G29, that looks really great to me! Do you need to do bench run in for the engine? or how is the run in process like for a heli gas motor?

The HWC29 mated to their conversion kit for the T700 should work very well:

http://www.centuryheli.com/products/...tml?pageid=755

There are some great videos of them performing some exciting 3D on youtube.