Best engine for the Sportster ?

Hello to all,

I apologize for not writing in your language, I do intend to learn it someday. I have been an enthusiast of this little airplane for a long time. Unfortunately it is no longer sold in the USA but I am willing to buy it from France and ship it if necessary. There is no other better performing aircraft on so little HP anywhere. My question to the forum group is this - is the Rotax 900 series still the best engine choice for this airframe ?  I see a few examples of the UL Power engine in a few pictures of a Sportster.  I believe this engine is heavier but also advertised to have more power.
What say all of you ?
Merci,
Randolph

Hi Randolph,

I am wondering where did you found the info about the UL Power being more powerfull than the Rotax; can you please clarify this point?

Many thanks,
Regards,

Luciano

Yes, I'm just going by advertised horsepower - 130hp vs. 100 or 115. Not at all scientific I know but I am giving the engine manufacturer the benefit of the doubt.

I see ...

Thanks for the info
Luciano

Hi Randolph,

My Sportster with its Rotax 912 S (100 hp) and its fix pitch propeller (pitch settable on ground), can cruise at 160 kts TAS, with a 20.5 l/h fuel flow. So, yes, you are probably right when you say that 'There is no other better performing aircraft on so little HP anywhere'... Note that in bumpy conditions this light bird becomes uncomfortable and you must reduce the speed to less than 143 kts and sometimes lesser. But nevertheless, it’s really a wonderful plane that gives its pilot very great feelings.

If you take in account its VNE (never exceed speed) of 173 kts without parachute and 143 kts with the BRS parachute, I don't think it would be reasonable to use a more powerful engine, but that’s only my own opinion…

Regards

Alain

Alain,
Thank you for your reply. I have an LSA airplane now with a Rotax 912uls and I am very comfortable with that engine. I have found it to be pretty much bullet-proof. Starts like a car and just runs no matter what. I am wondering though why the difference in VNE for parachute aircraft vs. non parachute ? Is this due to deployment of the chute ? I would like to have this option but not if it is going to cause me to have to fly slower. Could you not just use the higher VNE so long as you do not deploy the chute above 143 kts IAS ?
Thanks,
Randolph

About the VNE limitation:
First of all, I made a mistake: the limited VNE is not as I said 143 kts but 146 kts (or maybe 162 kts):

here is the sentence extracted from the French flight manual:

"La Vne de tout avion équipé d'un parachute BRS-5 1050 est limitée à 270 km/h – 146 knots (voir manuel d'utilisation BRS)."

and here is the sentence extracted from the English flight manual:

"Vne of all Aircraft equipped with BRS-5 1050 parachute is limited to 162 knots (refer to BRS user's manual)."

So, there is a limitation: 146 or 162 kts... I don't have the BRS manual for checking...

The limitation is due to max speed for the safe chute deployment.

Alain

We are in the process of editing a Service Bulletin that will give the same VNE to all Sportster models, with or without parachute, to around 167 knots (310km/h). This limitation was coming from the BRS parachute, but they have updated their limitations.

François,

What about the MCR-UL equiped with a parachute ?

tks

Luciano

Luciano,

the ULC will also be concerned by the SB!

François

Thanks a lot François.
Let's then wait for this/these SB
Luciano