credence,

Thanks for the info.

Your info is great as you may be one of the few that not only has converted a 30 sized nitro heli to Electric, but you also have a Trex 600 to compare it to.

I have seen a Trex 600 in a shop and thought my nitro may have looked a bit sturdier. (just guessing though). Didnt think they may have built them that way to compensate for the vibration associated with operating single piston engines.

The fact that they are heavier than an original electric may actually put off many people converting their nitros to E unless the battery prices drop QUITE CONSIDERABLY, as even a Trex 600 only gives you 8 minute flight times with a $300USD battery.
Also Ive seen a Trex 600 for sale for around $500 - $600USD (Heli, ESC, Motor, BEC). So with the price of batteries so high You would be better off buying a Trex 600 than converting a 30 sized nitro.
Also Trex 600 parts are much cheaper than the nitro heli parts I believe.

Im surprised at the cost of batteries for these things. Also at the cost of ESC and motors. It may just be me, but Ive just bought an OS37SZ-H engine for around $150USD, which to me sounds a reasonable price for such an engine. But for some reason I just consider $200USD for a brushless ESC, or $150USD or for a brushless motor quite expensive. Why are they so expensive to produce, or are the prices inflated for some reason.
As you say you may be able to pick up an ESC and motor cheaper than those prices, but with a heli the size of a Trex 600, it would have to be reliable.

Thanks for the video link. Its certainly a bit noisier than my Trex 450.
So what sort of flight time do you get from your (30 Hawk conversion) and what capacity Lipos are you using. Are you using 2x 3S 4000MaH in series. I guess you would only get about 5 minute flight times.

Im happy with my decision to buy a new nitro engine rather than convert it to electric. But maybe in a year if prices fall it may be a different story.