Use of Opal fuel in 912ULS

[Flyingphot]

Hi

 

Can anyone give me info on the use of Opal 91 fuel as available in communities in NT. Can it be used in 912 ULS engine and does octane booster work with it.

 

Cheers Bill

 

 

[Downunder]

Some info here.

 

Rotax 912 UL with Opal Fuel - Remote Communities

 

Probably best to mix with carried avgas at 3 to 1 I think, but have no personal experience.

 

I see octane booster as a last resort..... to get you out of trouble.

 

 

[Nobody]

BP claim that Opal fuel has a minimum octane rating (RON) of 91. It might be more but they don't guarantee it.

 

Rotax document SI-912-016 R4 says that for the 80hp 912 the minimum RON is 90 and for the 100hp 912s the minimum RON is 95.

 

On that basis you should not run the Opal fuel in the 100 HP engine but it would be ok in the 80hp engine. I know that people have used Opal in the 100 HP engine and not had issues but perhaps they were just lucky...

 

 

[cscotthendry]

BP claim that Opal fuel has a minimum octane rating (RON) of 91. It might be more but they don't guarantee it.Rotax document SI-912-016 R4 says that for the 80hp 912 the minimum RON is 90 and for the 100hp 912s the minimum RON is 95.

 

On that basis you should not run the Opal fuel in the 100 HP engine but it would be ok in the 80hp engine. I know that people have used Opal in the 100 HP engine and not had issues but perhaps they were just lucky...

I Agree, it might get you out of a pinch, but I wouldn't use 91 octane long term in the 100HP Rotax.

I would especially not use 91 octane in an engine that uses Evans coolant as you would almost guarantee that you'd get detonation (knock) in the engine due to the higher operating temps with Evans.