700N headspeed OS91HZ

[machasm]

Hi guys,
I was under the impression that it was good practise to get the engine to run in its power band where possible.
I have an OS91HZ in the 700 and the specs show that it develops its max HP when running at 15000 rpm.
On the 700 with a 8.2:1 gear ratio this equates to a headspeed of 1829 rpm.
Having spoken to others it would seem that most run their HS around the 1900 to 1950 mark.
So my question is which is right?
Ade.

[robgt]

You want to run it a bit above the power band so when you load it up it will drop into the power band and pull you through a manoeuvre.

I generally run around 2000 to 2050 on my 90's.
Cheers,
Rob

[Mojo]

Hi Ade,

Running the engine above its peak rpm means that when you load the engine it drops into its power band and not come out of it.. If that makes any sense

Mo

[Mojo]

And i am too slow again!!

[millerman]

dont know but i would sure be interested to know as im running 1950 and it bogs doing tick tocks

[machasm]

1950 sounds OK millerman. Perhaps its a tuning issue.
Ade.

[millerman]

yep i think its too rich roll on the sunny weather eh

[Tim Procter]

I generally run around 2000 to 2050 on my 90's.
Cheers,
Rob

You animal.

[chris jones2.4]

im running my 700 t the same as rob, 2050rpm, it seems to have plenty of power here

[Rotorhead]

Mine is set at 2050, I've seen people run them even higher, 2150.

[0h5h1t]

I have been running my 700's at 2050 for a while but am going to reduce the head speed now due to having piston and ring problems on my 91HZ's.. I don't know if the high speeds have been causing issues but am going to see how it goes at lower headspeed, say 1900.

[Made2Fade]

I have been running my 700's at 2050 for a while but am going to reduce the head speed now due to having piston and ring problems on my 91HZ's.. I don't know if the high speeds have been causing issues but am going to see how it goes at lower headspeed, say 1900.

Funny you should say this but i used to run 2050 ++ headspeeds on my 700 when i first got it. I had similar problems and put it down to the higher headspeeds i was running. I have no explanation of it other than this also. I have now reduced headspeed to 1900/1950 and everything seems to be running okay since the piston/ring change.

[millerman]

just for refrence as im gonna have a tuning session on saturday how many turns out are people on the high needle and medium needle and have you altered the mixture screw anoyingly i can tune a nitro/petrol car engine but not sure of the sound for helis yet as the 700 is my first nitro any hints tips would be great

[machasm]

just for refrence as im gonna have a tuning session on saturday how many turns out are people on the high needle and medium needle and have you altered the mixture screw anoyingly i can tune a nitro/petrol car engine but not sure of the sound for helis yet as the 700 is my first nitro any hints tips would be great

It depends a lot on nitro content and even varies between manufacturers of the same nitro content. (I had to go in 9 clicks when running a tank of rapicon 30 from my usual wildcat 3LDV!).
Just go with what the manual says and then tune from there.
Ade.

[Geek]

Ade which governor you running?
If your using a Align one what sort of figures you running in you transmitter?
also which tranny you running?

Thanks just going to start building mine