Return-Path: Received: from frontend2.cwpanama.net ([201.225.225.168] verified) by logan.com (CommuniGate Pro SMTP 4.2.5) with ESMTP id 523541 for flyrotary@lancaironline.net; Mon, 08 Nov 2004 19:13:33 -0500 Received-SPF: none receiver=logan.com; client-ip=201.225.225.168; envelope-from=rijakits@cwpanama.net Received: from [201.224.93.110] (HELO usuarioq3efog0) by frontend2.cwpanama.net (CommuniGate Pro SMTP 4.2.1) with SMTP id 30296780 for flyrotary@lancaironline.net; Mon, 08 Nov 2004 19:13:00 -0500 Message-ID: <008e01c4c5f0$ad3ebf50$6e5de0c9@usuarioq3efog0> From: "rijakits" To: "Rotary motors in aircraft" References: Subject: Re: [FlyRotary] Re: EWP Date: Mon, 8 Nov 2004 19:11:35 -0500 MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_008B_01C4C5C6.C3B12720" X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 6.00.2741.2600 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2742.200 This is a multi-part message in MIME format. ------=_NextPart_000_008B_01C4C5C6.C3B12720 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable MessageLet's go green :)!! ----- Original Message -----=20 From: Russell Duffy=20 To: Rotary motors in aircraft=20 Sent: Sunday, November 07, 2004 7:09 PM Subject: [FlyRotary] Re: EWP Rusty I don't see, how more cooling flow at low rpm will cool better, = there is still no change in radiator-size/airflow/etc.=20 It's pretty well established that more flow equals better cooling. = I'm not qualified to explain it, but plenty of people here are, and you = can probably find ton's of info in the archives. =20 I believe that's where people are wrong: Most car radiators are way to = big for the average driving, so increased cooling flow will reduce = overheating at to low a speed. But in your aircraft you will have the = radiator sized to the minimum possible to reduce drag. Just because you = pump the water more often through the radiator (that what it comes down = to when you say more flow...) it will still not cool better if the = radiator cannot get rid of the heat. I think to improve this the only = way to go is to improve the radiator airflow. Your radiator should be = big enough to handle continous max power at minimum indicated airspeed = and AOA. If you have overheating problems at idle at taxi speeds, more = flow in the system will solve the problem without increasing the airflow = through the radiator......... no cavitation at high rpm: use underdrive pulleys=20 And make the low rpm overheating worse. see above... and maintain the belts in correct alignmentand tension and you will = never loose one..........:)=20 I'd be more or less willing to agree with this. If I had a factory = set of pulleys, accessory mounts, and adjustment arms, I wouldn't be as = worried. Unfortunately, many of us are forced to make our own accessory = mounts. I've even had to use a pulley that needed to be modified to fit = the shaft on my alternator. The chances of a failure with these added = variables is far more likely than stock, and as I mentioned, broken or = thrown belts have stranded me on two occasions, both in factory = applications. =20 (I have abour 5000 hrs flying time in front of belts double-v-typ as = the only means of powertransfer from the engine to the rotor....)=20 How much do you think Robinson spent developing that v-belt drive? It = had better work :-) Exactly! Now why would I not want to copy him?=20 Use a double-v-arrangement withat least double the capacity needed = with a constant tension idler pulley and you should never have any = problems. Cheers, Rusty (I hate belts, and they hate me)=20 DOn't get me wrong, I know there a a lot of factory pumps that are a = disgrace to pumps in general and should be called junk! What I say is the concept to use a waterpump with belt drive is about = as simple as it goes. Change for a good aftermarketpump, a good set of = pulleys adjusted for your rpm needs, align them as good as possible, use = aquality belt, a springloaded idler and you are done.=20 Somewhere in another post on this newsletter, same thread, someone = said that I am wrong concerning the need for a bigger battery wit a EWP. Well you don't need a bigger battery unless you would like to keep = your sparetime to engine shutdown the same as without the EWP. You also = will need a bigger alternator...about 4 to 7 amps bigger, according to = the numbers showing up on the list :)=20 Thomas J. ------=_NextPart_000_008B_01C4C5C6.C3B12720 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Message
Let's go green :)!!
----- Original Message -----
From:=20 Russell=20 Duffy
Sent: Sunday, November 07, 2004 = 7:09=20 PM
Subject: [FlyRotary] Re: = EWP

Rusty I don't = see, how more=20 cooling flow at low rpm will cool better, there is still no change in=20 radiator-size/airflow/etc. 
 
It's pretty well established that more = flow equals=20 better cooling.  I'm not qualified to explain it, but plenty = of=20 people here are, and you can probably find ton's of info in the=20 archives.  
I believe that's where people are wrong: = Most car=20 radiators are way to big for the average driving, so increased cooling = flow=20 will reduce overheating at to low a speed. But in your aircraft you = will have=20 the radiator sized to the minimum possible to reduce drag. Just = because you=20 pump the water more often through the radiator (that what it comes = down to=20 when you say more flow...) it will still not cool better if the = radiator=20 cannot get rid of the heat. I think to improve this the only way to go = is to=20 improve the radiator airflow. Your radiator should be big enough to = handle=20 continous max power at minimum indicated airspeed and AOA. If you have = overheating problems at idle at taxi speeds, more flow in the system = will=20 solve the problem without increasing the airflow through the=20 radiator.........
 
 no cavitation at high rpm: use = underdrive pulleys 
 
And make the low rpm overheating=20 worse.
see above...
 and maintain the belts in = correct=20 alignmentand tension and you will never loose = one..........:) 
 
I'd be more or less willing to agree with = this. =20 If I had a factory set of pulleys, accessory mounts, and = adjustment arms,=20 I wouldn't be as worried.  Unfortunately, many of us are = forced to=20 make our own accessory mounts.  I've even had to use a pulley=20 that needed to be modified to fit the shaft on my = alternator. =20 The chances of a failure with these added variables is far more likely = than=20 stock, and as I mentioned, broken or thrown belts have stranded=20 me on two occasions, both in factory=20 applications.   
 
 (I have abour 5000 hrs flying = time in=20 front of belts double-v-typ as the only means of powertransfer from = the engine=20 to the rotor....) 
 
How much do you think Robinson spent = developing=20 that v-belt drive?  It had better work=20 :-)
Exactly! Now why would I not want to copy = him?=20
Use a double-v-arrangement withat least = double the=20 capacity needed with a constant tension idler pulley and you should = never have=20 any problems.
 
Cheers,
Rusty (I hate belts, and they hate=20 me) 
 
DOn't get me wrong, I know there a a lot of = factory pumps=20 that are a disgrace to pumps in general and should be called=20 junk!
What I say is the concept to use a waterpump = with belt=20 drive is about as simple as it goes. Change for a good = aftermarketpump, a good=20 set of pulleys adjusted for your rpm needs, align them as good as = possible,=20 use aquality belt, a springloaded idler and you are done.=20
 
Somewhere in another post on this newsletter, = same=20 thread, someone said that I am wrong concerning the need for a bigger = battery=20 wit a EWP.
Well you don't need a bigger battery unless = you would=20 like to keep your sparetime to engine shutdown the same as without the = EWP.=20 You also will need a bigger alternator...about 4 to 7 amps bigger, = according=20 to the numbers showing up on the list :)
 
Thomas J.
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