X-Virus-Scanned: clean according to Sophos on Logan.com From: "William Jepson" Received: from mail-vk0-f50.google.com ([209.85.213.50] verified) by logan.com (CommuniGate Pro SMTP 6.2c1) with ESMTPS id 9499492 for flyrotary@lancaironline.net; Thu, 23 Feb 2017 19:25:31 -0500 Received-SPF: pass receiver=logan.com; client-ip=209.85.213.50; envelope-from=wrjjrs@gmail.com Received: by mail-vk0-f50.google.com with SMTP id k127so4300657vke.0 for ; Thu, 23 Feb 2017 16:25:33 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=mime-version:in-reply-to:references:from:date:message-id:subject:to; bh=Jz08zyjRLEYVymZkiiP8ge1rMi8lI3R/gZwVQNZbaY8=; b=mQbAt7N/odOitNSUygAdNOW2w9bO+TGmfRBBGZv8z7v54Nw5CBwREfFNu0k6yMka+M CCnEbL+VEZUFgXrxUwqWU2dEmR8aMWEV3s/u45ArqB+FtZ/BK9SHFbGtmM+R45mvISbh ul4hzsO/xZTKr30ManppgESgjrSj5HYPEzIkPIjhlI7d+XkHsD8E7wGMyE/RXkN3oZQb OVjwBB1MVLHw6vstY2n85+KtVCa82h0ub+JWNxIAt5XxXbCIOFJ8ipjUPwGYHnLp8qOc BfFW9kDlOLdzT+1z897QVJcC9s5y4kn+HWimNDvbn2s/ejn4jMFZuEtbB7+OtFUttqy1 QNgA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:in-reply-to:references:from:date :message-id:subject:to; bh=Jz08zyjRLEYVymZkiiP8ge1rMi8lI3R/gZwVQNZbaY8=; b=kah6WjJJ+oBxyCAHypMEkhd69K5uO6CzAWqfefD/TOU9F75VAQK1OHtQPERsTKhEpE uXiQKl0D3+tnOSXT91iS9qT+DnpNYJSx+kY0bH2Kp1e3C454A9j+BIMm/rI2pjGgMK9A cRMmIpG93V6I04A334Pi2YodBNBX2D0moGAJh8jzF4E657+k7jQ2urPeNwW2GAH7yMjX T8Sn3xlguLdoXlXondQrZKWMSuWZ8X/aEd35HAh/JW0XVbgLfelTZv7igbe/PZJNFpt8 WhRdHslqbWZSgFKPouYPHVRvOMe3SgRkvUwMlKdxwZ7B9LHY/y7h0c84YUn9txnp91rl 83gg== X-Gm-Message-State: AMke39kfzHx3Doa73UcG9woypcjCigaYJbjBuPi6u2R9sH8NV9NdL11IqUyIul/nmIUBf35iImyd+9CYfwDQhw== X-Received: by 10.31.150.134 with SMTP id y128mr18065130vkd.102.1487895915035; Thu, 23 Feb 2017 16:25:15 -0800 (PST) MIME-Version: 1.0 Received: by 10.31.56.18 with HTTP; Thu, 23 Feb 2017 16:25:14 -0800 (PST) In-Reply-To: References: Date: Thu, 23 Feb 2017 16:25:14 -0800 Message-ID: Subject: Re: [FlyRotary] Boost Port Carb Efficiency To: Rotary motors in aircraft Content-Type: multipart/alternative; boundary=001a1141d6007a84ee05493bc36c --001a1141d6007a84ee05493bc36c Content-Type: text/plain; charset=UTF-8 Brock, For aircraft use anyway it is best to use all the ports. Don't forget that the "boost" port opens in the car at about 3K RPM and in aircraft use you would rarely be below that! I also am sure that the best configuration for aircraft is Peripheral port period. Much more efficient at the higher outputs needed for aircraft use. Bill Jepson On Thu, Feb 23, 2017 at 2:26 PM, durabol35@yahoo.com < flyrotary@lancaironline.net> wrote: > Dear FlyRotary Group > > My name is Brock and I've recently joined this group. I am working on a > original design Rotary Powered WIG (Wing In Ground-Effect) vehicle that > flies in the cushion of air between then wing and water. Eventually I would > like to build a plane (LSA like) I can take up in the air but for now want > to focus on this. I'm still in the research phase (for the last 15 years!) > but hope to start building shortly. I'm presently reading through RWS > literature: Magazine articles, the Aviator's Guide to Mazda Rotary > Conversion and the Mazda Papers and have learned a bunch. > > I've recently obtain a running 1986 RX-7 13B rotary engine. For simplicity > I'm considering converting to carbs and aftermarket ignition since I'm > worried about getting the wiring sorted out for the stock ECU since it > seems complicated and RWS says it is not suitable for airplane use. I've > gotten the impression that a properly adjusted carbs will perform similar > to EFI (that doesn't use direct injection) for spinning a propeller and RWS > reports only 10% worse mileage. I had a look at the RWS website but didn't > see the ignition system that uses the stock crank angle indicator and coils > so I'm wondering if it is still available or a suitable replacement? > > I was planning to use separate carbs and fuel pumps for each rotor for > redundancy so I can shut down one rotor and limp home in an emergency like > an ignition or fuel system failure. I know this type of redundancy > increases the number of parts that could potentially fail but it still > seems like a good idea to me. The engine has a 6 port intake with the two > center ports feeding both rotors while the outer ports each feed one rotor. > I was planning to seal the 2 center ports and just use the outer ports but > that was before I read that they are "boost" port and close much later than > the center ports. Like the name suggests I assume that the boost ports are > for high power output but I'm worried about fuel efficiency just using the > boost ports. I've read in the "Aviator's Guide to Mazda Rotary Conversion" > the author used a 3 carb setup and 2 fuel pump and in normal operation all > three carbs are used and for an emergency the engine can run on either the > outer two carbs or the center carb. Based on this example the center ports > should be used but the engine does run (in an emergency) on just the outer > boost ports. I suspect the center ports are important or Mazda wouldn't > have made the engine that way, but perhaps just for low power levels or > emissions? > > Brock > --001a1141d6007a84ee05493bc36c Content-Type: text/html; charset=UTF-8 Content-Transfer-Encoding: quoted-printable
Brock,
For aircraft use anyway it is best to use all t= he ports. Don't forget that the "boost" port opens in the car= at about 3K RPM and in aircraft use you would rarely be below that! I also= am sure that the best configuration for aircraft is Peripheral port period= . Much more efficient at the higher outputs needed for aircraft use.
<= div>Bill Jepson

On Thu, Feb 23, 2017 at 2:26 PM, durabol35@yahoo.com <flyrotary@lancaironline.net&= gt; wrote:
Dear FlyRotary Group

My name is Brock and I've recently joined this group. I am working on a original design Rotary Powered WIG (Wing In Ground-Effect) vehicle that flies in the cushion of air between then wing and water. Eventually I would like to build a plane (LSA like) I can take up in the air but for now want to focus on this. I'm still in the research phase (for the last 15 years!) but hope to start building shortly. I'm presently reading through RWS literature: Magazine articles, the Aviator's Guide to Mazda Rotary Conversion and the Mazda Papers and have learned a bunch.

I've recently obtain a running 1986 RX-7 13B rotary engine. For simplicity I'm considering converting to carbs and aftermarket ignition since I'm worried about getting the wiring sorted out for the stock ECU since it seems complicated and RWS says it is not suitable for airplane use. I've gotten the impression that a properly adjusted carbs will perform similar to EFI (that doesn't use direct injection) for spinning a propeller and RWS reports only 10% worse mileage. I had a look at the RWS website but didn't see the ignition system that uses the stock crank angle indicator and coils so I'm wondering if it is still available or a suitable replacement?

I was planning to use separate carbs and fuel pumps for each rotor for redundancy so I can shut down one rotor and limp home in an emergency like an ignition or fuel system failure. I know this type of redundancy increases the number of parts that could potentially fail but it still seems like a good idea to me. The engine has a 6 port intake with the two center ports feeding both rotors while the outer ports each feed one rotor. I was planning to seal the 2 center ports and just use the outer ports but that was before I read that they are "boost" port and close much later than the center ports. Like the name suggests I assume that the boost ports are for high power output but I'm worried about fuel efficiency just using the boost ports. I've read in the "Aviator&#= 39;s Guide to Mazda Rotary Conversion" the author used a 3 carb setup and 2 fuel pump and in normal operation all three carbs are used and for an emergency the engine can run on either the outer two carbs or the center carb. Based on this example the center ports should be used but the engine does run (in an emergency) on just the outer boost ports. I suspect the center ports are important or Mazda wouldn't have made the engine that way, but perhaps just for low power levels or emissions?

Brock

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