Return-Path: Received: from ms-smtp-01.southeast.rr.com ([24.93.67.82] verified) by logan.com (CommuniGate Pro SMTP 4.1b8) with ESMTP id 2436035 for flyrotary@lancaironline.net; Thu, 19 Jun 2003 15:01:53 -0400 Received: from o7y6b5 (clt78-198.carolina.rr.com [24.93.78.198]) by ms-smtp-01.southeast.rr.com (8.12.5/8.12.2) with SMTP id h5JIuBpN023203 for ; Thu, 19 Jun 2003 14:56:12 -0400 (EDT) Message-ID: <002201c33696$65f73540$1702a8c0@WorkGroup> From: "Ed Anderson" To: "Rotary motors in aircraft" References: Subject: Re: [FlyRotary] Ivo Magnum Pitch Question Date: Thu, 19 Jun 2003 15:10:07 -0400 MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 6.00.2800.1106 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2800.1106 Hi Tommy, Congratulations on the "caged animal". Regarding the prop, no nothing about the Ivo, however, you need to tune it for max thrust! Now there is a bit of helpful information. You do have a thrust meter , don't you? {:>) Not having a thrust meter, you need to balance power making with thrust making requirements (at least enough to get you safely off the ground). One thing you definitely do not want to do initially is tune the prop it for max rpm - while that may produce gobs of power, you will have your pitch set too low to produce a safe amount of thrust. First if you are only getting 25" MAP and you are near sea level, then you have airflow interference problems. I would not like less than 28" MAP at WOT. So either you throttle is not opening all the way or you have one hell of a filter or you are at 5000 feet elevation. Think about it, if you stop your engine with the throttle open the MAP will read 29.92" (if at sea level and standard day). So even if you run your engine out of power (prop load too heavy), you should still be able to get within 1" or so of 29.92". Now you stated that you thought you had some throttle left. I would suggest that go out fire that animal up again and advance the throttle 'till it won't advance any further and then check your MAP. If not close to 29.92 then start checking your intake. I am going to send an e mail to a friend of mine who has a rotary in a Glastar with an IVO prop and see if he can tell us what his is set at for take off. Will get back to you with what I find. Best Regards Ed Anderson ----- Original Message ----- From: "Tommy James" To: "Rotary motors in aircraft" Sent: Thursday, June 19, 2003 2:19 PM Subject: [FlyRotary] Ivo Magnum Pitch Question > Okay, here is a real test of this groups aeronautical acumen. > > On the front of my Glastar is a ground adjustable Ivo Magnum (3 blade). The > "destructions" advise that it is adjustable from 30" to 90" pitch by turning > a large adjustment screw which twists a cam in each blade. This screw has 5 > turns stop to stop, or 12" per full turn of the screw. The prop is > currently set at ~54" of pitch. I ran the engine this morning to ~4500rpm > and 25" MAP. While there was throttle left, the engine did not seem to want > to advance from there. > The plane was bouncing around like a caged animal... This is new ( and > exciting) to someone used to C152s. > > The test: > How would one determine the correct pitch for first flight and what is the > guesstimate of what that pitch should be? > > Regards, > Tommy James<>< > ps. no further starter problem > > > > >> Homepage: http://www.flyrotary.com/ > >> Archive: http://lancaironline.net/lists/flyrotary/List.html >