Return-Path: Received: from wb1-a.mail.utexas.edu ([128.83.126.134] verified) by logan.com (CommuniGate Pro SMTP 4.2b3) with ESMTP-TLS id 3220089 for flyrotary@lancaironline.net; Fri, 07 May 2004 11:14:36 -0400 Received: (qmail 11126 invoked from network); 7 May 2004 15:14:34 -0000 Received: from dhcp-191-101.per.utexas.edu (HELO benefits3.mail.utexas.edu) (146.6.191.101) by wb1.mail.utexas.edu with RC4-SHA encrypted SMTP; 7 May 2004 15:14:34 -0000 Message-Id: <5.1.1.5.2.20040507101032.022c0908@localhost> X-Sender: msteitle@mail.utexas.edu@localhost X-Mailer: QUALCOMM Windows Eudora Version 5.1.1 Date: Fri, 07 May 2004 10:13:51 -0500 To: "Rotary motors in aircraft" From: Mark Steitle Subject: Re: [FlyRotary] Re: E-shaft pulley diameters In-Reply-To: Mime-Version: 1.0 Content-Type: multipart/alternative; boundary="=====================_64015968==.ALT" --=====================_64015968==.ALT Content-Type: text/plain; charset="us-ascii"; format=flowed Al, That's probably good advice. Do you know what other 20B guys are doing? I only know of Tom Parkes that has actually flown. I think I have his e-mail address and can ask him about his pulley arrangement. Thanks, Mark At 07:55 AM 5/7/2004 -0700, you wrote: > > >Subject: [FlyRotary] Re: E-shaft pulley diameters > > > >Now this is beginning to make sense to me. The stock 20B e-shaft pulley is > >5.5", and the wp pulley is 4". I guess Mazda did this in the Cosmo since > >it was a luxury car (with an automatic trans) and not subject to as high of > >rpms as the RX-7's. Another probability is that the Cosmo's electrical > >demands were greater, and therefore required the alternators to be spun > >faster. I need to find (or build) a 4" multi-V e-shaft pulley, or change > >everything to a dual V-type so I can use undersize after-market pulleys. > > > >Mark S. > > > >I my opinion, using a speed reduction pulley on the alternator may make >some sense, because you can get plenty of charging at a lower speed; but I >wouldn t slow down the water pump unless I knew I had excess cooling >capacity in the system. > > > >Al --=====================_64015968==.ALT Content-Type: text/html; charset="us-ascii" Al,
That's probably good advice.  Do you know what other 20B guys are doing?  I only know of Tom Parkes that has actually flown.  I think I have his e-mail address and can ask him about his pulley arrangement. 

Thanks,
Mark


At 07:55 AM 5/7/2004 -0700, you wrote:

 

Subject: [FlyRotary] Re: E-shaft pulley diameters

 

Now this is beginning to make sense to me.  The stock 20B e-shaft pulley is

5.5", and the wp pulley is 4".  I guess Mazda did this in the Cosmo since

it was a luxury car (with an automatic trans) and not subject to as high of

rpms as the RX-7's.  Another probability is that the Cosmo's electrical

demands were greater, and therefore required the alternators to be spun

faster.  I need to find (or build) a 4" multi-V e-shaft pulley, or change

everything to a dual V-type so I can use undersize after-market pulleys.

 

Mark S.

 

I my opinion, using a speed reduction pulley on the alternator may make some sense, because you can get plenty of charging at a lower speed; but I wouldn t slow down the water pump unless I knew I had excess cooling capacity in the system. 

 

Al
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