flyrotary@lancaironline.net Mailing List Archive

Will,

Note that we only have been running Peripheral Port in this discussion. For your stated needs you could run a somewhat "detuned" version. The small port version of the 13B would work fine, and you could even run a fairly restrictive muffler which would push the HP down into the 170-180 range. It would be much quieter, and absolutely reliable. Our small port engine becomes intake limited at about 6500 RPM. The exhaust also has an effect, but any good muffler design will work if the materials will handle the high exhaust temps of the rotary. On a P-ported engine the exhaust is very straightforward. The lowest back pressure wins. DO NOT NEGLECT THE MUFFLER ON YOUR ROTARY ENGINE! Mistral the Swiss based company trying to certify a rotary package crashed their test aircraft because of a muffler failure. We have used various mufflers some custom some OTC. The best purchased mufflers were Flowmaster mufflers which we still cut open and replaced the guts with 316 SS or Inconel of the same thickness. We are building and testing some custom mufflers which we are testing on both the aircraft dyno and on an RX7 vintage race car. DO NOT USE A CONVENTIONAL "GLASS PACK" TYPE MUFFLER ON YOUR ROTARY. The heat of the exhaust and the sonic impulses will gut a glass pack like a fish. Those mufflers will often fail in the span of 1 (one) flight. The packing will certainly be gone.

BILL

On Wed, Jan 24, 2018 at 5:30 AM, william Aldridge willja67@hotmail.com <flyrotary@lancaironline.net> wrote:

Bill,

Since you brought up p- port sizes I'd like to ask your recommendation. Having in the neighborhood of 250 hp would be nice for bragging rights (roughly same power to weight ratio as a corsair) but since my plane is a derivative of the 1/2 scale war replicas that were only designed for 100 hp I'm a little worried about ripping the wings off since my bird is a lot cleaner aerodynamically. So in terms of mission, simplicity and cost what are your recommendations for the induction system?

Thanks

Will Aldridge

Sent from my Verizon, Samsung Galaxy smartphone

-------- Original message --------

From: "William Jepson wrjjrs@gmail.com" <flyrotary@lancaironline.net>

Date: 1/24/18 12:25 AM (GMT-07:00)

To: Rotary motors in aircraft <flyrotary@lancaironline.net>

Subject: [FlyRotary] Re: Simple bullet proof Ignition systems?

Will,
The test engine uses the distributor from the early 13B but no high tension cap. If you look at the "cold" side of the engine in the video you can easily see it. It has a custom cap/cover. The ignition uses a old Mallory optically triggered ignition. It works like the 4 cylinder two coil dual lead wasted spark ignition. I'm not sure if it's even still available. The injection is a standard Airflow Performance aircraft mechanical fuel injection. I do plan to test a SDSEFI full engine management system. The test engine is the exact spec that the original Powersport was going to sell. As simple as possible. For $14,000 complete! I told Steve if Everett hadn't been killed in the crash they could have become a homebuilt engine standard. The cost will be higher now, if only because the parts prices have gone up. That engine makes as much as 195 HP. That is our small port engine! The other engine has 1-3/4" ports. The small port is 1-5/16" both are P port engines. I believe the big port engine will be about 240 HP at 7000 rpm. I wish there was a big enough base to sell to. If there was I would already be doing it full time. Right now it is a passionate hobby.

Bill Jepson

On Jan 23, 2018 10:40 PM, "william Aldridge willja67@hotmail.com" <flyrotary@lancaironline.net> wrote:

Thanks Bill,

That cpi looks pretty good. For right now at least it's on my short list. I've got a engine core that may or may not be useable, I'm about to start tearing it down. So I'm a ways from needing the ignition system but want to be ready and informed when the time comes.

Btw i saw your post looking for engines to test mount your psru. How's that coming? And i guess more appropriate to this thread what ignition system are you running on the engine in this video: https://youtu.be/EfreUJt-Fsk

Thanks,

Will Aldridge

Sent from my Verizon, Samsung Galaxy smartphone

-------- Original message --------

From: "William Jepson wrjjrs@gmail.com" <flyrotary@lancaironline.net>

Date: 1/23/18 3:56 PM (GMT-07:00)

To: Rotary motors in aircraft <flyrotary@lancaironline.net>

Subject: [FlyRotary] Re: Simple bullet proof Ignition systems?

Will,
Ross doesn't generally list Rotary engines in his catalog, but he isn't against them. He has a injection that still lists rotary engines. To run his ignition only you would likely need to get an aluminum e-shaft pulley to install his magnets. He has his own Hall effect sensors. He used to sell both ignition units and full EMS systems. Don't know if he is still doing it individually. The advantage of his system is that he does do aircraft stuff. His business has in fact gravitated towards aircraft since so many cars now come with their own systems unless it is a full custom build they often don't need an EMS. BTW I don't work for them or get anything for recommending their products. I met Ross at Reno while crewing for a friend on a Sport Class entry. Ross was providing an EMS for a very fast Questair Venture running a turbo Lyc. Very good guy. A 4 cylinder unit with dual plug coils will run the rotary just fine. The timing is the same, except that the coil isn't wasting a spark in the exhaust, instead it is firing both plugs on a single rotor. Ross' site still lists his "coil pack ignition" for vehicles with mechanical injection or carburetors.

Bill

On Tue, Jan 23, 2018 at 12:24 PM, william Aldridge willja67@hotmail.com <flyrotary@lancaironline.net> wrote:

Looked over his site this morning and if i read It right there was only a fuel injection controller/ system, no ignition control. Out was here: http://www.sdsefi.com/prices.html

If I'm reading that chart at the top of the page right he doesn't supply ignition systems for the rotary.

Sent from my Verizon, Samsung Galaxy smartphone

-------- Original message --------

From: "William Jepson wrjjrs@gmail.com" <flyrotary@lancaironline.net>

Date: 1/23/18 12:14 PM (GMT-07:00)

To: Rotary motors in aircraft <flyrotary@lancaironline.net>

Subject: [FlyRotary] Re: Simple bullet proof Ignition systems?

Guys, I don't know if he is still offering it but SDSEFI (Simple Digital Systems, www.SDSEFI.com) has both an ignition only system and a full engine management system that will work for a 13B. His system doesn't have split firing, but most people running a high performance rotary do both plugs at once anyway. He has a newer dual in one box system, FOR AIRCRAFT that could be run simultaneously to do a split fire and be fully redundant.
Bill Jepson

On Tue, Jan 23, 2018 at 6:08 AM, Finn Lassen finn.lassen@verizon.net <flyrotary@lancaironline.net> wrote:

Maybe someone out there has a RWS original ignition controller they want to let go of. No programming required, uses 13-B standard pickup and ignition coils. Of course you'll have to use carburetor(s).

I have one, but really don't want to let go if it. Its simplicity is nice if just want to get 13-B running. (All you have to do is set timing and tune carburetors.)

Finn

On 1/22/2018 11:31 PM, william Aldridge willja67@hotmail.com wrote:

I'm building a one off experimental, therefore, i need a simple bullet proof Ignition system and am wondering what is currently available? I have the 2007 version of Tracy's conversion manual in which he gives the option of either using the stock distributor etc, or use a computerized ignition system with stock or Chevy ls coils.

To reiterate, since the airframe is unproven i only want to be worried about flying the plane not the engine. It's a small plane the size that would normally have 100hp installed (1200 lbs gross) so if I only have 150 hp I'll still be doing good. In other words I'm willing to sacrifice a little power for a lot of reliability and simplicity.

I don't like the idea of the stock distributor, since there isn't much room in the cowl and there's no redundancy. I also don't like the idea of electronic ignition. I've read enough stories of lengthy battles to get the computers to play nice with the engine and don't want to go that route. Again simplicity and reliability at the expense of power and fuel efficiency is what I'm after. Also planning on using a carb for the same reason. I can always upgrade the engine later if i want.

I figure there has to have been some other options come up in the last 10 years. I used to subscribe to the other guys list, but don't know if any of the ideas he put forth have merit.

Thanks,

Will Aldridge

Ps my build thread on hba here: http://www.homebuiltairplanes.com/forums/showthread.php?t=16831

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