X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from fmailhost06.isp.att.net ([204.127.217.106] verified) by logan.com (CommuniGate Pro SMTP 5.2.10) with ESMTP id 3287630 for flyrotary@lancaironline.net; Wed, 12 Nov 2008 13:49:10 -0500 Received-SPF: none receiver=logan.com; client-ip=204.127.217.106; envelope-from=keltro@att.net Received: from fwebmail07.isp.att.net ([207.115.11.157]) by isp.att.net (frfwmhc06) with SMTP id <20081112184834H0600rsvn7e>; Wed, 12 Nov 2008 18:48:34 +0000 X-Originating-IP: [207.115.11.157] Received: from [65.255.87.167] by fwebmail07.isp.att.net; Wed, 12 Nov 2008 18:48:33 +0000 From: "Kelly Troyer" To: "Rotary motors in aircraft" Subject: IVO Props, etc. Date: Wed, 12 Nov 2008 18:48:33 +0000 Message-Id: <111220081848.16806.491B2500000BC204000041A622230706129B0A02D29B9B0EBF019D9B040A05@att.net> In-Reply-To: X-Mailer: AT&T Message Center Version 1 (Oct 30 2008) X-Authenticated-Sender: a2VsdHJvQGF0dC5uZXQ= MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="NextPart_Webmail_9m3u9jl4l_16806_1226515713_0" --NextPart_Webmail_9m3u9jl4l_16806_1226515713_0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable Doug, Did Ross state his "IVO" diameter and if 2 or 3 blades !!...............= =20 -- Kelly Troyer=20 "Dyke Delta"_13B ROTARY Engine=20 "RWS"_RD1C/EC2/EM2=20 "Mistral"_Backplate/Oil Manifold=20 -------------- Original message from DLOMHEIM@aol.com: --------------=20 Ross Farnham, who posts in the Van's Airforce "alternative engine" forum (a= nd who if he wasn't a Subie guy would most likely be a regular on this list= ); has done quite a bit of testing with the IVO Magnum "high pitch" version= on his RV-6A, turbo Subie. The best "top speed" (for what that's worth in= this day and age) I could find in his data was at a DA of 17,000 ft. and "= 34 inches 5000 rpm, mixture -10%, 181 knots TAS". That really isn't too b= ad for the price you pay for an IVO in my opinion. See this link for his I= VO testing information: http://www.sdsefi.com/rv13.htm His web pages also fully document the many cooling modifications he went th= rough with his installation until it finally was "right", much like those w= ho have gone before on this list have had to do. This also is well documen= ted and makes for interesting reading if you haven't checked out his site b= efore. http://www.sdsefi.com/rv12.htm I plan on using an IVO on my RV-9A installation since it appears from Ross'= s data that it should provide more than adequate climb performance and will= also cruise well in the 150-160 mph range (where I plan on spending most o= f my time). An MT would be nice, but the cost is prohibitive on my budget.= Here is a summary of Ross's IVO conclusions from his web page: 07/21/04 At the 90 hour engine/prop time mark we have some more observations on the = IVO Magnum: 1. We have had no issues with bolts or blades coming loose. 2. The in-flight adjustment works well. We use a 0-20 amp ammeter to judge = blade position. 3. After the first set of brushes laid down carbon on the slip rings, brush= life now exceeds 30 hours between changes 4. Despite having too low a reduction ratio for our airframe, the Magnum of= fers good takeoff and climb performance. Medium speed cruise performance is= comparable to other certified aircraft propellers. High speed performance = also seems comparable although we'd like to have a lower reduction ratio to= turn the prop faster and absorb more hp. 5. Given the speed vs. fuel flow considerations on our turbocharged RV6A, t= his prop is matched well and is a viable alternative to expensive constant = speed, certified propellers. A fixed pitch prop on the turbocharged engine = would degrade performance considerably, especially in the takeoff, climb an= d high altitude cruise regimes. 6. A slight vibration is set up if the propeller is coarsed out too much fo= r the flight speed, likely due to the blade being partially stalled. 7. Ambient temperature and altitude (density altitude) affect pitch angles = required for a given hp and rpm. For takeoff using 38 inches MAP, 4800 engine rpm/ 2182 prop rpm we set pitc= h at 3 amps fine of neutral pitch. This is at a hp of around 170, prop torq= ue is 409 ft./lbs. Density altitude 3500-4500 MSL. For climb at 35 inches MAP, 4500-4800 engine rpm/ 2045-2182 prop rpm we set= pitch at 2 amps fine to neutral. This is at an IAS of 80-95 knots. Hp is 1= 50-155, torque at prop is about 374 ft./lbs. Density altitude around 6000 M= SL. For cruise at 30 inches MAP, 4200 engine rpm/ 1909 prop rpm we set pitch at= 13 amps coarse. This is at an IAS of 130 knots. HP is around 114, torque a= t prop about 314 ft./lbs. Density altitude 11,000 MSL. We don't run the pitch past 15 amps coarse and figure that this results in = a pitch of 95 to 100 inches. (note: italics are mine...) Doug Lomheim RV-9A; 13B/ FWF Get the Moviefone Toolbar. Showtimes, theaters, movie news & more! --NextPart_Webmail_9m3u9jl4l_16806_1226515713_0 Content-Type: multipart/related; boundary="NextPart_Webmail_9m3u9jl4l_16806_1226515713_1" --NextPart_Webmail_9m3u9jl4l_16806_1226515713_1 Content-Type: text/html; charset="utf-8" Content-Transfer-Encoding: quoted-printable
Doug,
   Did Ross state his "IVO" diameter and if 2 or 3 blades !!= ............... 
--
Kelly Troyer
"Dyke Delta"_1= 3B ROTARY Engine
"RWS"_RD1C/EC2/EM2
"Mistral"_Backplate/Oil Manifol= d



 
-------------- Original message from DLOMHEIM@aol.com: -----= ---------

Ross Farnham, who posts in the Van's Airforce "alternative engine= " forum (and who if he wasn't a Subie guy would most likely be a regul= ar on this list); has done quite a bit of testing with the IVO Magnum = "high pitch" version on his RV-6A, turbo Subie.  The best "top sp= eed" (for what that's worth in this day and age) I could find in his data w= as at a DA of 17,000 ft. and " 34 inches 5000 rpm, mixture -10%, = 181 knots TAS".  That really isn't too bad for the price you pay = for an IVO in my opinion.  See this link for his IVO testing= information:  http://= www.sdsefi.com/rv13.htm
 
His web pages also fully document the many cooling modifications = he went through with his installation until it finally was "= right", much like those who have gone before on this list have ha= d to do.  This also is well documented and makes for interesting = reading if you haven't checked out his site before.   http://www.sdsefi.com/rv12.htm
 
I plan on using an IVO on my RV-9A installation since it appears from = Ross's data that it should provide more than adequate climb performance and= will also cruise well in the 150-160 mph range (where I plan on spending m= ost of my time).  An MT would be nice, but the cost is prohibitiv= e on my budget.  Here is a summary of Ross's IVO conclusions from= his web page:
 
07/21/04

At the 90 hour engine/prop time mark we have some more observations on t= he IVO Magnum:

1. We have had no issues with bolts or blades coming loose.

2. The in-flight adjustment works well. We use a 0-20 amp ammeter to jud= ge blade position.

3. After the first set of brushes laid down carbon on the slip rings, br= ush life now exceeds 30 hours between changes

4. Despite having too low a reduction ratio for our airframe, t= he Magnum offers good takeoff and climb performance. Medium spe= ed cruise performance is comparable to other certified aircraft propellers<= /EM>. High speed performance also seems comparable although we'd l= ike to have a lower reduction ratio to turn the prop faster and absorb more= hp.

5. Given the speed vs. fuel flow considerations on our turbocharged RV6A= , this prop is matched well and is a viable alternative to expensive consta= nt speed, certified propellers. A fixed pitch prop on the turbocharged engi= ne would degrade performance considerably, especially in the takeoff, climb= and high altitude cruise regimes.

6. A slight vibration is set up if the propeller is coarsed out too much= for the flight speed, likely due to the blade being partially stalled.

7. Ambient temperature and altitude (density altitude) affect pitch angl= es required for a given hp and rpm.

For takeoff using 38 inches MAP, 4800 engine rpm/ 2182 prop rpm we set p= itch at 3 amps fine of neutral pitch. This is at a hp of around 170, prop t= orque is 409 ft./lbs. Density altitude 3500-4500 MSL.

For climb at 35 inches MAP, 4500-4800 engine rpm/ 2045-2182 prop rpm we = set pitch at 2 amps fine to neutral. This is at an IAS of 80-95 knots. Hp i= s 150-155, torque at prop is about 374 ft./lbs. Density altitude around 600= 0 MSL.

For cruise at 30 inches MAP, 4200 engine rpm/ 1909 prop rpm we set pitch= at 13 amps coarse. This is at an IAS of 130 knots. HP is around 114, torqu= e at prop about 314 ft./lbs. Density altitude 11,000 MSL.

We don't run the pitch past 15 amps coarse and figure that this results = in a pitch of 95 to 100 inches.

(note:  italics are mine...)

 

Doug Lomheim

RV-9A; 13B/ FWF

 




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