While there is no question that P porting will provide more power and its reputation for poor idle (whether deserved or not) at low rpm  does not affect its suitability for our use, I think there are other considerations.  IF you can buy a properly make P port or have the knowledge and machinery to do it yourself correctly , it might be well worth doing.  However, I have found that approaches  designed from max power out put at high rpm may not always be compatible with longevity or reliability, factors of most importance in aircraft – so you need to check into that.  I tried a Rotary Racing manifold early on and while it was probably great for a rotary turning 9000+ rpm, it really performed poorly at 5000-6000 rpm.  Once I replaced it with an intake design from my engine’s actual operating range – power improved considerably.

 

I, for one, found that building my own aircraft and converting a pretty much stock 13B for aircraft use was about all I could handle back almost 15 years ago.  With the knowledge on this list that is now pretty much a straight forward thing - but still a lot of work.  I fly a 13B rotated 90 deg so that the Plugs are UP – so I am certainly not against experimenting with the rotary engine.

 

But, I have know of several folks who tried  P porting own their own and ran into a much bigger challenge than they had anticipated.  For one thing, it turns out the best P port parameters for aircraft use are different than that used by the all-out racers.  A second thing is some folks have run into challenges in sealing the coolant galley after cutting the hole in the rotor housing, the interface to the steel sheath inside the rotor housing also needs to be done correctly as well.  All challenges that can be overcome – but require time and $$.

 

So can it be done? – certainly it can be done. Is it the best approach for what you have in mind – only you can decide that.   But, the more different you are from the stock engine the more benefit and the more disadvantage you will encounter.  While some early experimenters – Everret Hatch comes to mind (whose project was sold to PowerSport) who put one in an Rv-4 that Allen Tole? Flew to a screaming take off and climb out at Sun & Fun – before blowing a bearing in the PSRU (NOT a RWS PSRU)- showed some initial promises for the P port in aircraft – But, I have not seen any follow up or growth in that area for aircraft.

 

The real question is the benefit worth the extra effort – I think many have decided the stock engine perhaps with turbo is the way to go.  I think the P port is an elegant approach to getting more power – but, more of a challenge than I’m interested in – and it would not do a thing for me given the way I fly.  Naturally the flight environment and needs of others will vary from my requirements. 

 

Bill Jepson already mentioned the simplification of the intake (at least space wise) of the intake.  It is also the lightest modification you can make to produce that kind of power as it should  end up weighing a bit less than a stock 13B and certainly less than a 13B with a Turbo.

 

So if you are up to the challenge – go for it, but be aware it is a challenge.

 

Best Regards

 

Ed

 

 

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