J 160 cruise speed/rpm

[Guest Pioneer200]

I have been viewing the Jabiru site and read that they advertise the J 160 cruise speed of 100 knots @ 3050 rpm.

 

They also say fuel burn of between 13 - 16 litre an hour.

 

I fly a J160 here in NZ and our plane will do more than 100 knots at 3050 rpm, probably closer to 110 knots.

 

But @ that rpm I believe it burns way more than 16 litres an hour.

 

I work on 20 litre hour for cross countries @ 2900 rpm

 

Is cruising @ 3050 rpm to hard on the engine??

 

Cheers:big_grin::big_grin:

 

 

[sseeker]

We cruise at 2800rpm on our prop and we can get about 100kts. If you have a read through the J160 pilot operating handbook the aircraft has a max cruise of 112kts. If we cruised at 3000rpm we'd be getting around 112kts or above. There are about 4 different props for the 2200 engine 2 of which are approved for the J160C I think. As for fuel planning we go by 14/L an hour at 2800rpm. And I'm not sure where it says cruise at 3050rpm because I'm pretty sure that's what the engines maximum revs are.

 

 

[Vev]

If you take a look at the "JabChat News Letter" (July 2009) on the Jab site they have listed fuel burn per RPM for the recommended carby jetting ... the attached is a cut and paste from Jabchat.

 

 

 

 

 

 

 

 

 



RPM Litres/hour

 

 

 

 

 

 

2600 13.4

 

 

 

 

 



2700 14.1

 

 

 

 

 



2800 16.5

 

 

 

 

 



2900 17.4

 

 

 

 

 



3000 24.3

 

 

 

 

 

Full Power (3175) 28.5

 

 

 

In terms of max RPM, I beleive this to be 3300 RPM for the 2200/4 engine. The guys at Jab always tell you not to baby the engine and drive it hard, therefore I really wouldn't think 3050 rpm as being too hard on the engine.

 

 

 

Cheers

 

Jack

 

 

 

[sseeker]

Veverjg,

 

Correct me if I'm wrong, one of the props at our school was chipped. It was immediately replaced with another approved prop and I believe this was called a 'cruising prop'? And our engine usually sits at 3000-3300rpm (as said above) on takeoff but when this prop was put on we were getting 2800-2900rpm on takeoff full power, so really your maximum capable engine revs are down to the loading on the prop?

 

 

[Vev]

Yes you are right, but your take off and climb rpm will always be lower than max rpm in S&L flight.... in S&L flt you will see the engine speed increase if you held full power.

 

I have a varible pitch prop on my 160 and pull 2900 in static mode, 3000.3050 rpm in climb and 3300 in S&L flight at full power. I tend to cruise around 3000/3100 @ 100/105 knts.

 

Cheers

 

Jack

 

 

[sseeker]

Ah ok I see now, thanks for the explanation.