Os 105 hzr and os 91hzr 3d black head

[stunks]

Apart from the specks do u think there is really a huge difference in power.

91 specks

Specification
Displacement: 0.91 cu in (14.9 cc)
Bore: 1.09 in (27.7 mm)
Stroke: 0.98 in (24.8 mm)
Output: 3.6 hp @ 15500 rpm
Practical RPM Range: 2,000-16,500
Weight (w/o Muffler): 21.2 oz (603 g)


105 specks

Specification
OSMG1961 105HZ-R
Displacement: 1.048 cu in (17.17 cc)
Bore: 1.442 in (29 mm)
Stroke: 1.024 in (26 mm)
Practical RPM: 2.000-16,500
Output: 3.8 ps @ 15,000 rpm
105HZ Weight: 21.03 oz (596 g)
105HZ-R Weight: 21.46 oz (608 g)

all in all the 105 is only .2 of hp over the 91, so for those who had tried these engine what feedback can u give thanks.

[Stuart]

I came from an older version of the OS line so I'm expecting to see a bigger jump in hp I think its about .5hp for me....will find out more at the weekend I hope...

[jwatts007]

I saw the spec for the TT100 I think it was 3.91hp @ 14500rpm, I would not take too much notice to be honest............

[maxw]

Hi
I have the os speed 3D black and it has bags of power
I went from the HZ-R to the 3D and there is same diffence in HP from them as there is from the 3D to the 105 although you can feel more power it's not a huge diffence
So what I'm saying is really its down to cost

If the 3D is alot cheaper than the 105 go for the 3D very good engine


If interested I have a gallon old os 91HZ-R 3D for sale
It's mint and still needs running in
£240

Gone elec now so it's a spare as running 3 other 3D engines

[3d_willz]

I have only just brought the 91 3d engine and then we had the 105 come out. But if I was shopping for an engine now then I would go for the 105. I've never run a ys engine but this is only because back in the day the ys had a different crank so I would have to buy more parts to get the heli in the air. I dont know if this is still an issue but if not then I wouldn't mind trying the ys120 as I hear it runs better on 15% fuel lol

[steve_b]

One thing to consider for the 105 is that it's been designed to run on 15% - 20% nitro so even if it is a bit more expensive then the overall running costs will be less, because you don't have to use high % nitro fuel

[Guest]

The 91 HZ-R in my Flybarless Srimok on 20% SLV is more than enough. I put a YS 120 in it but took it out just didn't run as smooth for me and random bits started failing just sounded like my machine was having a hard time with it. On the HZ-R it just runs and pulls fine. If I were buying again I would buy the 105.

MJ

[stunks]

3.6 hp and 3.8 ps what does the hp And ps stands for and witch is better


Johnshrinks

[Guest]

Both measurements of power. Hp= Horsepower and PS= metric horsepower. Just compare like for like.

MJ

[jamiem]

3.8ps is 3.74hp, so the difference is seemingly even less than their misleading specs suggest

[stunks]

3.8ps is 3.74hp, so the difference is seemingly even less than their misleading specs suggest

so does the bore and stroke make any difference also?

[Guest]

You'll have more torque which is a good thing :-)

MJ

[Chris Boughton]

So what I'm saying is really its down to cost

If the 3D is alot cheaper than the 105 go for the 3D very good engine

The OS105 is £332.99 and the OS 91HZR 3D is £369.99!!!
The OS105 has to be the way to go!!!! Considering its designed to run on %15, jus makes it a great bonus!!

[steve_b]

The OS105 is £332.99 and the OS 91HZR 3D is £369.99!!!
The OS105 has to be the way to go!!!! Considering its designed to run on , jus makes it a great bonus!!

And the 105 with the regulator is £379.99, which for the extra £10 would be the one to got for.

[Paulice]

Like with all motors it is not just the HP alone it is the combination of HP and Torque, the 105 would have more Torque over the 91 and as Torque is the turning power even if they had the same HP the 105 would be less likely to bog down over the 91!

As they never post Torque figures with the HP you can't really tell if a motor is more powerful or not.