Thanks Lyn
So PP’ing a Renesis 4 port provide significantly better breathing.
Is there a porting option for the Renesis 4 port that yields significant improvement, say 10% hp or is there too little material to play with?
Cheers
Steve Izett
>
> A Periphery ported side exhaust is better than both intake and exhaust being periphery ported. Neither the intake or exhaust port ever closes. So, there is exhaust dilution of the intake flow based on the amount of exhaust back pressure. Up to the point where RPMs do not allow enough time for this to occur.Then it sort of steps up on the cam and the power comes on as if by an electric switch. The full periphery engine tunes like a dirt bike. The intake length and diameter and the exhaust length and diameter tune like a trombone.
> A periphery ported 12-A can do 310 HP at 10,000 RPM. A 13-B can do 330 HP at 10,000 RPM. We have to be under 105Db at 50 feet at full throttle. The Renesis has zero overlap. But it had a Micky Mouse intake with 2 different tuned lengths.
> There was a builder at Sun&Fun years ago who had a RX-7 transmission for speed reduction. It worked fine. Later he had the idle too slow and it shook the gears of of 2nd gear. I forgot his name but he died of cancer.
> LEH
>
> Mat,
>
> It will only idle hot at that rpm. (1800). Cold it is 2000 plus. Yes P ported and the advance seems to vary little from 20 degrees. Running Fueltech ECU. And running cheapest gas.
>
> Neil.
>
>
> Sent: Wednesday, October 21, 2020 1:38 AM
> Subject: [FlyRotary] Re: Tuning
>
>
> Steve = Using Megasquirt for ECU. How is your flight testing going?
>
> Jeff = I meant prop rpm. Using Neil's PSRU, which is 3.17. I just bumped up my idle to around 800prop (2500engine). I forgot to add, I am P-Port which causes a need for higher idle.
>
> Lynn = Idle can be that high? Usually I see rotary idle around the 10-18 range, but that is for a car. Little different with a prop on 100% of the time.
>
>
> Neil = That is a nice idle. I forget, are you P-Port? What is your timing at?
>
> Dave = 35 all time? Doesn't that seem really high for rotary. Pump gas? Lynn was saying 24 degrees for 87 octane.
>
>
> - Matt Boiteau
>
>
>
>
> Hi there Matt and all
>
> What computer is controlling your fuel and spark Matt?
>
> Ive left the timing of the EC2 on the Renesis 4 port at Tracy’s default and haven’t changed it but was wanting to do some experimenting.
> I take it that the timing setting in the EC2/3 will vary the whole timing curve over the rpm/load envelope.
>
> Cheers
>
> Steve Izett
> Renesis 4 port EC2 EM3 RD1-C
>
>
>
>
> >
> > Split table.
> >
> > - Matt Boiteau
> >
> >
> >
> > What AFR and timing are people running for idle, taxi, takeoff, climb, cruise, descent?
> >
> > idle = 11afr, 20 timing
> > I seem to have to be around 11afr for it to stay alive. Still trying to get it to idle around 600rpm, maybe bump it up to 700rpm to be smoother without dieing and shaking apart.
> >
> > taxi / takeoff / climb = 13.2afr, 28 timing
> >
> > cruise - not sure aft, 28 timing
> >
> > decent - not sure aft, 32 timing
> > Not sure what the plane likes. I tried 14afr, but the MAP really get's low and engine shakes. Guessing it should be more rich?
> >
> > I attached the timing table and split rotary table (second email). Not sure how to tune timing, I just want safe values for now.
> >
> >
> > - Matt Boiteau
> > --
> > <split.JPG>--
>
>
> --
>
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