Return-Path: Received: from relay02.roc.ny.frontiernet.net ([66.133.182.165] verified) by logan.com (CommuniGate Pro SMTP 4.3c3) with ESMTP id 811322 for flyrotary@lancaironline.net; Sat, 19 Mar 2005 09:51:57 -0500 Received-SPF: pass receiver=logan.com; client-ip=66.133.182.165; envelope-from=canarder@frontiernet.net Received: from filter03.roc.ny.frontiernet.net (filter03.roc.ny.frontiernet.net [66.133.183.70]) by relay02.roc.ny.frontiernet.net (Postfix) with ESMTP id 36890370251 for ; Sat, 19 Mar 2005 14:51:11 +0000 (UTC) Received: from relay02.roc.ny.frontiernet.net ([66.133.182.165]) by filter03.roc.ny.frontiernet.net (filter03.roc.ny.frontiernet.net [66.133.183.70]) (amavisd-new, port 10024) with LMTP id 18151-01-6 for ; Sat, 19 Mar 2005 14:51:11 +0000 (UTC) Received: from [127.0.0.1] (67-137-85-150.dsl2.cok.tn.frontiernet.net [67.137.85.150]) by relay02.roc.ny.frontiernet.net (Postfix) with ESMTP id 904EB37016C for ; Sat, 19 Mar 2005 14:51:10 +0000 (UTC) Message-ID: <423C3C65.9060101@frontiernet.net> Date: Sat, 19 Mar 2005 08:51:17 -0600 From: Jim Sower User-Agent: Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.7) Gecko/20040514 X-Accept-Language: en-us, en MIME-Version: 1.0 To: Rotary motors in aircraft Subject: Re: [FlyRotary] BMW and EWP References: In-Reply-To: Content-Type: text/html; charset=us-ascii Content-Transfer-Encoding: 7bit X-Antivirus: avast! (VPS 0511-1, 03/17/2005), Outbound message X-Antivirus-Status: Clean X-Virus-Scanned: by amavisd-new-20040701 (2.0) at filter03.roc.ny.frontiernet.net But would the limit be EWP or radiator?  You seem to be presuming that the pump would be the limiting factor.  Is there a reason why the radiator wouldn't get maxed out first?  Automobiles seem to have radiator volume of around 1.0 - 1.5 in^3 / hp.  Airplanes 2.0 - 2.5 or better.
Appears my biases lie on the other side of the line from yours ... Jim S.

Al Gietzen wrote:

Just to keep you thinking; someone made the comment that the BMW would have to be capable of pulling up the mountain at 60 mph with its 4 passengers – or whatever.  Doing that with you 3000 lb car up a 15% grade would require about 21 more hp than driving on the level; which might take about 60, so 80 – 90 hp?  Design the cooling jacket for a low flow EWP and this is easy.

 

One of the most significant “torture tests” they do on the engines is WOT simulated acceleration through 3 gear changes up to equivalent of 70 mph; then decelerate back to zero and do it over again.  They do this for thousands of cycles.  It’s a tough test but again; average power is low; I don’t know what, but less then half rated power. 

 

Let’s say the rated hp is at 4800 rpm. The only time you approach rated power with this car is WOT at 4800 rpm at sealevel on a 60F day.  How long would you ever sustain that condition?

 

Al