View Full Version : Which OS engine for Stratus ?
simon109
05-30-2006, 02:07 PM
Hi,
Bit confused on what OS to put in a Stratus, not got my stratus yet still deciding etc.
I know I need 8.18 version but which OS should I put in ? I have read that some don't fit and need fins sanding, which one(s) drop straight in and is there anything that is required for the engine mounting that doesn't come with the kit ?
Thanks
Simon.
Gary O
05-30-2006, 04:02 PM
The new Stratus kits come with everything you need to put any of the OS 91's in them. When the SZ came out MA had to ammend the engine mounting plate and they've done that. As far as sanding fins, if you run the OMI Viperhead, and/or the OMI carb set up depending on whether or not you get the OS pumped SZ. If you run the Viperhead you don't have to do anything but bolt it in. If you run the OS head it won't fit in the MA fan shroud with cutting it, but as David H has said, if you sand the fins enough to get it to fit it's fine.
simon109
05-30-2006, 05:26 PM
Ok thanks so,
These one's won't fit without sanding the fins
OS.91SZ-H
OS.91SZ-H PS-Hyper Engine
OS.91SX-H 'C' SPEC
OS.91SX-H 'C' Spec PS
These one's fit straight in
OS.91SX-H C Spec - Viper
OS.91SX-H C SPEC PS - Viper
Simon.
Thats correct.
a SZ would fit with a Viper head with no mods too.
simon109
05-31-2006, 06:13 PM
Thanks.
Does the YS91 fit ok ? but I would need 8.45 ratio.
Simon.
Yes it does, and Yes you need 8.45 for YS. although some guys like 8.18 with YS too.
simon109
05-31-2006, 06:17 PM
Thankyou.
Simon.
TonyM
06-06-2006, 07:25 AM
With the 91 SZH it is producing its torque at a much higher rpm than the older C Spec,?
Whats the opinion of using 8.45 with the SZ
anyone doing that?
z11355
06-06-2006, 07:42 AM
It seems to work OK although general consensus is that 8.08-8.18 works better
than 8.45 for the SZ
Gary O
06-06-2006, 11:35 AM
The SZ with the 8.18 is a hoss. Loads of power to spare. I have Stratus helis with the C-Spec / OMI Kline setup, YS 91, and the SZ / OMI Kline. The SZ is the strongest of the 3. The YS is a good motor but you have to really watch your collective management to make sure you don't load it too hard. I fly the YS Stratus a lot and when I pick up the SZ Stratus it's like flying a different heli. I have noticed that the SZ seems to run slightly hotter than the C-Spec and quite a bit hotter than the YS, but when I tried to run it a little richer a lot of that power wasn't there.