Trex 600 OS70 Big Block Conversion

[leckylee]

I know this maybe mad but has anyone done this conversion to the 600N.

I have an OS70 and a 600N and was hoping to find some info and maybe some pictures and instructions to do the conversion.

Thanks in advance

Lee

[sacko]

There is a thread on Helifreak where someone has put a 91 in a 600.

Prob worth a read.

[tonystevens]

Tim critchley at our club put a 90 in a 600, he might chip in if hes reading

[Chris Boughton]

Jesus a 91 in a 600!!!! I bet thts mental!!!!!!!!!!!!!!!!!!!!

[Steve]

Someone on here has done the 70 in a 600 conversion. I remember reading about it, but can't remember who. Quite a regular poster, so should chime up soon I'm sure.

[electricsceadu]

fitting an os 55, ys56 or rossi 57
or waiting for the ys60 (the new one based on the 50 size crank case)
will give better performance than the 70
and a lot less hassle

if you must try it
from what i remember reading you alter the 600 engine mounts and cut the crank length down (scrapping the 70/90 motor for its proper sized heli)

[Paulo uk]

I have an os70 in a 600. I have also modded a 600 for a 91hz. The 70 is a much better idea and really easy to do. I haven't looked at it for ages, but I will take a look over it and let you know the details. Iirc you just alter the bottom plate and engine mounts and of course cut the crank shaft down on the engine.

Paul

[trillian]

The thing is you'll need an unusual pinion size because the 70 revs a couple thousand RPM
less but you'll be aiming for a fairly high headspeed.

I have a Robbe Futura (.90 size airframe) with an OS70 and it's a very smooth engine. I would
imagine a 600 would be a rocket with that engine if you can get the right gearing.

[Paulo uk]

Trillian, you don't need to change the pinion it works very well on stock.

Paul

[Leo77]

The fan hub will have to be drilled and tapped out bigger as the thread on the crank of the 70 is bigger then the 50. I started this conversion ages ago but never finished it.

[Steve]

Just run it on a governor and the extra oomph should greatly reduce bogging.

[Bruinbear]

I have to ask Lee... Why ?
Have you considered running 550 size blades with a 50/55/57 motor.
Just go the whole hog and stick a 91 in it. It's bound to strip all the gears !

[Supercaptaincrash]

The power gained will be marginal against fitting a novarossi 57/os 55 and a lot less hassle! i bet you wouldnt even tell the difference!

[sacko]

...but he has an OS70 laying around, may as well use it instead of blowing £300 and gaining the same result

[leckylee]

I have to ask Lee... Why ?
Have you considered running 550 size blades with a 50/55/57 motor.
Just go the whole hog and stick a 91 in it. It's bound to strip all the gears !

LOL

Mike as you know I think the 600 N is quite underpowered for my useless collective management lol.

and just fancied the challenge, do you you fancy it with the raptor??