Received-SPF: none
 receiver=logan.com; client-ip=204.127.131.116; envelope-from=keltro@att.net
From: keltro@att.net (Kelly Troyer)
To: "Rotary motors in aircraft" <flyrotary@lancaironline.net>
Subject:  Re: Short intake manifolds
Date: Mon, 20 Dec 2004 05:00:48 +0000
Message-Id: <122020040500.22148.41C65C800004FDA2000056842158766720019D9B040A05@att.net>
MIME-Version: 1.0
Content-Type: multipart/alternative; boundary="NextPart_Webmail_9m3u9jl4l_22148_1103518848_0"


--NextPart_Webmail_9m3u9jl4l_22148_1103518848_0
Content-Type: text/plain
Content-Transfer-Encoding: 8bit

Paul,
   How about a photo of the new setup after you fly and are able to 
get the grin off your face !!
--
Kelly Troyer 
Dyke Delta/13B/RD1C/EC2 


-------------- Original message from "Paul" <sqpilot@bellsouth.net>: -------------- 


Tracy Crook wrote:

Should be an interesting experiment Paul,  can't wait to hear results.

 I tried a very short and now a medium-short manifold and find that it works well IF it is very "clean" (proper diameter runners, no change in cross sectional area, well matched to ports, etc, etc)  The very short runners gave up some power at climb rpm (FP prop) but did OK at cruise & top end.  The Medium-short version works about as well as my long (so-so clean) manifold (~17" runners)  and real good at top end.

FWIW, my guess about your dripping throttle body is condensation on the runners & throttle body walls.  Gravity does the rest.  Agravating the problem is the "cool side injectors".  Someone called this arrangement the "Holy Grail" of intake design.   I'd call it the "Sacred Cow".

Tracy   ( eat sacred cow for lunch).
Cut

Hi, Tracy....I have tried the short manifold, and I love it.  I left everything undisturbed except the manifold, a shorter throttle cable, and longer wires to the injectors/throttle position sensor.  The engine started fine (as it did with the longer intake runners). That's where the comparison ended.  With the same factory default settings on the ECU, the transition from idle to midrange was oh, so smooth. I used to think the long intake manifold had a smooth transition...until I tried the short Atkins intake manifold. A world of difference.  With the long intake runners, I could not advance above 1/2 throttle without the engine bogging down. Now, I can go to full throttle, and the brakes will not hold.  Smooth from idle to full power.   The best part....no after shutdown fuel drips at all.   With my 3 blade 64 x 78 prop, on three trials, my static rpm's were 4800, 5000 and 4800 rpm's.  Don't know what rpm I will get once the prop unloads in flight, but it is such an improvement over my long intake runners that always dripped fuel after shutdown.  I am finally excited about this aircraft.  It's climb performance was more like a Cessna 150 with the 4200 rpm's I was able to obtain on it's first flight, and downwind only provided 140 knots (didn't retract the nosegear).  I am optomistic that the additional static rpm's I am now getting should make a pleasant increase in performance. I have to run a few more wires around and away from the alternator belt, put adel clamps on the new fuel lines and finish installing a shorter throttle cable, then I will be able to fly it and see how much of an improvement I get.  There is no doubt that I have a lot more power (since I can now go to full throttle).  Take care....Paul Conner
--NextPart_Webmail_9m3u9jl4l_22148_1103518848_0
Content-Type: text/html
Content-Transfer-Encoding: 8bit

<html>
<!-- BEGIN WEBMAIL STATIONERY -->
<head></head>
<body>
<!-- WEBMAIL STATIONERY noneset -->
<DIV></DIV>
<DIV>Paul,</DIV>
<DIV>&nbsp;&nbsp; How about a photo of the new setup after you fly and are able to </DIV>
<DIV>get the grin off your face !!</DIV>
<DIV class=signature id=signature>--<BR>Kelly Troyer <BR>Dyke Delta/13B/RD1C/EC2 <BR><BR><BR><BR></DIV><BR>
<BLOCKQUOTE style="PADDING-LEFT: 5px; MARGIN-LEFT: 5px; BORDER-LEFT: #1010ff 2px solid">-------------- Original message from "Paul" &lt;sqpilot@bellsouth.net&gt;: -------------- <BR>
<BLOCKQUOTE style="PADDING-RIGHT: 0px; PADDING-LEFT: 5px; MARGIN-LEFT: 5px; BORDER-LEFT: #000000 2px solid; MARGIN-RIGHT: 0px"><BR>Tracy Crook wrote:<BR>
<BLOCKQUOTE cite=midlist-568561@logan.com type="cite">
<STYLE></STYLE>

<META content="MSHTML 6.00.2900.2523" name=GENERATOR><!--[gte IE 5]><?xml:namespace prefix="v" /><?xml:namespace prefix="o" /><![endif]-->
<DIV>
<DIV>Should be an interesting experiment Paul,&nbsp; can't wait to hear results.</DIV>
<DIV>&nbsp;</DIV>
<DIV>&nbsp;I tried a very short and now a medium-short manifold and find that it works well IF it is very "clean" (proper diameter runners, no change in cross sectional area, well matched to ports, etc, etc)&nbsp; The very short runners gave up some power at climb rpm (FP prop) but did OK at cruise &amp; top end.&nbsp; The Medium-short version works about as well as my long (so-so clean) manifold (~17" runners)&nbsp; and real good at top end.</DIV>
<DIV><FONT face=Arial size=2></FONT>&nbsp;</DIV>
<DIV>FWIW, my guess about your dripping throttle body is condensation on the runners &amp; throttle body walls.&nbsp; Gravity does the rest.&nbsp; Agravating the problem is the "cool side injectors".&nbsp; Someone called this arrangement the "Holy Grail" of intake design.&nbsp;&nbsp; I'd call it the "Sacred Cow".</DIV>
<DIV>&nbsp;</DIV>
<DIV>Tracy&nbsp;&nbsp; (&nbsp;eat&nbsp;sacred cow for lunch).</DIV>
<BLOCKQUOTE style="PADDING-RIGHT: 0px; PADDING-LEFT: 5px; MARGIN-LEFT: 5px; BORDER-LEFT: rgb(0,0,0) 2px solid; MARGIN-RIGHT: 0px">
<DIV><FONT face=Arial size=2>Cut</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT>&nbsp;</DIV>
<DIV><FONT face=Arial size=2>Hi, Tracy....I have tried the short manifold, and I love it.&nbsp; I left everything undisturbed except the manifold, a shorter throttle cable, and longer wires to the injectors/throttle position sensor.&nbsp; The engine started fine (as it did with the longer intake runners). That's where the comparison ended.&nbsp; With the same factory default settings on the ECU, the transition from idle to midrange was oh, so smooth. I used to think the long intake manifold had a smooth transition...until I tried the short Atkins intake manifold. A world of difference.&nbsp; With the long intake runners, I could not advance above 1/2 throttle without the engine bogging down. Now, I can go to full throttle, and the brakes will not hold.&nbsp; Smooth from idle to full power.&nbsp;&nbsp; The best part....no after shutdown fuel drips at all.&nbsp;&nbsp; With my 3 blade 64 x 78 prop, on three trials, my static rpm's were 4800, 5000 and 4800 rpm's.&nbsp; Don't know what rpm I will get once the prop unloads in flight, but it is such an improvement over my long intake runners that always dripped fuel after shutdown.&nbsp; I am finally excited about this aircraft.&nbsp; It's climb performance was more like a Cessna 150 with the 4200 rpm's I was able to obtain on it's first flight, and downwind only provided 140 knots (didn't retract the nosegear).&nbsp; I am optomistic that the additional static rpm's I am now getting should make a pleasant increase in performance. I have to run a few more wires around and away from the alternator belt, put adel clamps on the new fuel lines and finish installing a shorter throttle cable, then I will be able to fly it and see how much of an improvement I get.&nbsp; There is no doubt that I have a lot more power (since I can now go to full throttle).&nbsp; Take care....Paul Conner</FONT></DIV></BLOCKQUOTE></DIV></BLOCKQUOTE></BLOCKQUOTE></BLOCKQUOTE>
<!-- END WEBMAIL STATIONERY -->

</body>
</html>

--NextPart_Webmail_9m3u9jl4l_22148_1103518848_0--