Jabiru power increase

[Yenn]

The Rotec injection system is not really an injection system. It is just letting the fuel out into the airflow, via a pipe with holes in it so that the lowered pressure around the pipe draws the fuel out.

If you look back many years on this forum, one member did describe how he built a proper injection system, but he was a design engineer for one of the big motor companies. Mitsubishi, if my memory serves me right.

The Sonex manufacturers also sell a similar TBI to Rotec and I know that works very well.

[RFguy]

again, there's no power increase for the Jabiru because there is no thermal headroom for a power increase. period.

 

a normalizing turbo is not much of a good idea either because the cooling performance at altitude is reduced because there is less air.... 

 

 

 

 

[meglin]

On 19/05/2021 at 8:17 PM, lee-wave said:

The only way you can gain a real increase in performance without modification or weight increase is to put on a more efficient propellor.  Fitting a 60X40 in place of a 60X42 results in static revs increasing from roughly 2670rpm to 2890rpm which is equivalent to a 7 % increase in horsepower (I think the maths is right) .Certainly the take off performance is blistering... but the offside is there is a reduction in cruise speed ...

I agree with you. We have successfully used wooden propellers with a diameter of up to 68" on non-high-speed aircraft. We have also developed and use especially strong carbon fiber blades, the propeller diameter is 1620 mm = 63.8". They have been in operation for more than five years. Unfortunately, none of the engines that work with us has worked out the assigned resource.