Hirobo Freya 90 into Gas

[monkeyking]

Hi to all!
I am planning to convert my Hirobo Freya 90 into Gas.
I am from Argentina and here one galon of 15% nitro costs U$S40, its really killing me! I am wasting about U$S50 each time that I go to the field...

So...I have to select some things to start..
ENGINE
I was thinking to buy this from heliworld http://www.heli-world.com/detail.aspx?ID=8513 , I think that it is a good option (price/product), It seems to be a modified engine, somebody kwnos who mods them?
I am looking for an engine to have a performance like the ones that I have now with my OS 91 SX-H w/Pump.
The datasheet of this Zenoah says that it has 3.1 hp...so it has the same power of the OS, but I suppose that it is at lower rpm..here I have the first problem..

MUFFLER
I will use the Hatori that I have im my OS now, I now that is not the best, but its what I have now.

GEAR RATIO
I am thinking to use the 88T/13T from Century to get 1800 rpm in the main rotor at +/- 12000 rpm

Questions...
CLUTCH
Do you think that I can use the same that I am using now?

Suggestions about engine, gear ratio, other stuff????

I will post the advances

Thanks!

PS: sorry for my bad english :(

[Eyefly]

First may I ask: Why reinvent the wheel. If a gasser is what you want, sell the Freya and get a gasser. I will be much easier than a conversion.

[monkeyking]

Simple...I can sell my heli for $1200 complete here, and I have to spend that money to get the cheapeast Predator Gasser.... + main and rear blades + servos + gyro + muffler + governor..that its about $800 more...

Any other idea?

Thanks!

PS: here you have a link where you can see a guy that did a very good job and he is selling the kit...but he dont want to ship it to Argentina :(
http://www.modellhelischule.de/jmla/index.php?option=com_content&task=view&id=21&Itemid=54