X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from EXHUB003-3.exch003intermedia.net ([207.5.74.110] verified) by logan.com (CommuniGate Pro SMTP 5.2.10) with ESMTPS id 3325083 for flyrotary@lancaironline.net; Mon, 01 Dec 2008 10:31:31 -0500 Received-SPF: none receiver=logan.com; client-ip=207.5.74.110; envelope-from=jwhaley@datacast.com Received: from EXVMBX003-5.exch003intermedia.net ([207.5.74.45]) by EXHUB003-3.exch003intermedia.net ([207.5.74.110]) with mapi; Mon, 1 Dec 2008 07:30:55 -0800 From: Jeff Whaley To: Rotary motors in aircraft Date: Mon, 1 Dec 2008 07:30:56 -0800 Subject: RE: [FlyRotary] Hot first flight Thread-Topic: [FlyRotary] Hot first flight Thread-Index: AclTw8vDoeZ3GBZiRiCfWmucp4iZdAABWB5w Message-ID: References: In-Reply-To: Accept-Language: en-US Content-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: acceptlanguage: en-US Content-Type: multipart/alternative; boundary="_000_C03ABB0A7362B84BB53D544B3C305E0ED132CD4C11EXVMBX0035exc_" MIME-Version: 1.0 --_000_C03ABB0A7362B84BB53D544B3C305E0ED132CD4C11EXVMBX0035exc_ Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: quoted-printable Thanks Lynn for the technical info; I had not seen been to that website bef= ore ... Racing Beat I am well aware of. Actually I bought one of their doub= le alternator pulleys, which they claim reduces rpm by 20% ... other than a= luminum instead of steel it is same diameter of existing pulley. I'd like t= o change it anyway for the small weight gain and what-if due to belt breaka= ge ... but I can't get the nut off ... any hints? Jeff From: Rotary motors in aircraft [mailto:flyrotary@lancaironline.net] On Beh= alf Of Lynn Hanover Sent: Monday, December 01, 2008 9:46 AM To: Rotary motors in aircraft Subject: [FlyRotary] Hot first flight Thanks to you all for the congratulatory comments ... attached is a picture= of expansion tank and preflight roll-out ... the orange line is fuel retur= n; the brass is pressure gauge pickup and snifter valve installation. After reading Eds' email I now know why the water temperature was so high. = I installed a thermostat with the onset of cold weather, but I couldn't us= e the original Mazda thermostat because my temperature bulb protrudes acros= s the bypass hole. Originally the bypass hole was plugged and there was no= thermostat; however, I removed the bypass plug and used a non-Mazda thermo= stat !! ... so that's why the underside of the Mazda thermostat is so long!= Thanks Ed for setting me straight and based on your comment about 20% loss= of efficiency, I could possibly see 230F x 0.8 or as low as 184F on next f= light ... that would be great! For now the thermostat is gone and bypass is= re-plugged. Closer examination of the belt and rubber deposits on underside of top cowl= ing suggests the belt got jammed in the pulley and cut by friction. I tried again last night to remove the alternator pulley nut ... what's the= secret? Left-hand thread? Loctite or what? It's so tight I'm afraid of dam= aging something trying to get it off. Jeff Belt failures are in modern times, a very rare occurrence. Dual or multiple= belt installations are generally found where a single belt would be operat= ing at close to maximum capability and so are servicing the same pulleys. M= ultiple belts servicing some different pulleys are not in this class. For same pulley installations multiple belts need to be matched sets. The G= overnment uses thousands of sets of matched belts for large diesel trucks. = Some with 3 or 4 belts each.This is not a redundant system designed for rel= iability. In any case where a belt is run to death, or rock damaged, the re= maining belt(s) will often fail in the same instant by ingesting pieces of = the failing belt, it that is not the case, the remaining belt(s) will fail = just from operating close to their load limit. In every case, one must assu= me that the companion belt has suffered some damage, and it wont match the = length of any single belt installed along side it, so it (they) remaining b= elts should be discarded. If there is not an obvious FOD cause for the failure, the installation shou= ld be checked carefully for alignment, tension and stiffness (rigidity) at = high RPM. Also with accessories loaded and unloaded. The crank nose on the rotary is a weak point, and can fail right at the fro= nt main bearing if the belts are over tensioned. Note the mass of pulleys f= ound on some years of the cars. The single or double pulley in small diamet= er mounted close to the front cover, is less prone to failure just from the= lever arm difference. On assembly it is common to torque the pulley bolt t= o 95 foot pounds as this stiffens the stack of items clamped in place by th= e bolt. You must then check crank end play at the same torque, as some end = play is used up when this is done. There is a belt length that fits between= the water pump and crank pulley with the race pulley set, that fits perfec= tly with no idler. I discarded the first such belt after three years, altho= ugh there was no sign of wear at all, other than the writing was gone. The Racing Beat catalogue is the owners manual for rotary engines. Chuck fu= ll of things you should know. http://www.google.com/search?hl=3Den&ie=3DISO= -8859-1&q=3DRacing+Beat Also: From Mazda Competition, http://www.mazdamotorsports.com/webapp/wcs/stores/servlet/Info?catalogId=3D= 10001&storeId=3D10001&langId=3D-1&subject=3DtechInfo Lynn E. Hanover --_000_C03ABB0A7362B84BB53D544B3C305E0ED132CD4C11EXVMBX0035exc_ Content-Type: text/html; charset="us-ascii" Content-Transfer-Encoding: quoted-printable

Thanks Lynn for the technical info; I had not seen been to t= hat website before … Racing Beat I am well aware of. Actually I bought on= e of their double alternator pulleys, which they claim reduces rpm by 20% … othe= r than aluminum instead of steel it is same diameter of existing pulley. I’d= like to change it anyway for the small weight gain and what-if due to belt breakage= … but I can’t get the nut off … any hints?

Jeff

 

From: Rotary motors= in aircraft [mailto:flyrotary@lancaironline.net] On Behalf Of Lynn Hano= ver
Sent: Monday, December 01, 2008 9:46 AM
To: Rotary motors in aircraft
Subject: [FlyRotary] Hot first flight

 

Thanks to you all for the congratulatory comments … attached is a picture of= expansion tank and preflight roll-out … the orange line is fuel return; the bra= ss is pressure gauge pickup and snifter valve installation.

After reading Eds' email I now know why the water temperature was so high.  = I installed a thermostat with the onset of cold weather, but I couldn't use t= he original Mazda thermostat because my temperature bulb protrudes across the bypass hole.  Originally the bypass hole was plugged and there was no thermostat; however, I removed the bypass plug and used a non-Mazda thermos= tat !! … so that's why the underside of the Mazda thermostat is so long! = Thanks Ed for setting me straight and based on your comment about 20% loss of efficie= ncy, I could possibly see 230F x 0.8 or as low as 184F on next flight … th= at would be great! For now the thermostat is gone and bypass is re-plugged.

Closer examination of the belt and rubber deposits on underside of top cowling sug= gests the belt got jammed in the pulley and cut by friction.

I tried again last night to remove the alternator pulley nut … what's t= he secret? Left-hand thread? Loctite or what? It's so tight I'm afraid of damaging something trying to get it off.

Jeff

Belt failures are in modern times, a very rare occurrence. D= ual or multiple belt installations are generally found where a single belt woul= d be operating at close to maximum capability and so are servicing the same pull= eys. Multiple belts servicing some different pulleys are not in this class.

 

For same pulley installations multiple belts need to be matc= hed sets. The Government uses thousands of sets of matched belts for large dies= el trucks. Some with 3 or 4 belts each.This is not a redundant system designed= for reliability. In any case where a belt is run to death, or rock damaged, the remaining belt(s) will often fail in the same instant by ingesting pieces o= f the failing belt, it that is not the case, the remaining belt(s) will fail = just from operating close to their load limit. In every case, one must assume that the companion belt has suffered some damage, and it wont match = the length of any single belt installed along side it, so it (they) remaining b= elts should be discarded.  

 

If there is not an obvious FOD cause for the failure, the installation should be checked carefully for alignment, tension and stiffness (rigidity) at high RPM. Also with accessories loaded and unloaded= .

 

The crank nose on the rotary is a weak point, and can fail r= ight at the front main bearing if the belts are over tensioned. Note the mass of pulleys found on some years of the cars. The single or double pulley in sma= ll diameter mounted close to the front cover, is less prone to failure just fr= om the lever arm difference. On assembly it is common to torque the pulley bol= t to 95 foot pounds as this stiffens the stack of items clamped in place by the bolt. You must then check crank end play at the same torque, as some end pl= ay is used up when this is done. There is a belt length that fits between the water pump and crank pulley with the race pulley set, that fits perfectly w= ith no idler. I discarded the first such belt after three years, although there= was no sign of wear at all, other than the writing was gone. <= /o:p>

 

The Racing Beat catalogue is the owners manual for rotary engines. Chuck full of things you should know. http://www.google.com/search?hl=3Den&ie=3DISO-8859-1&q= =3DRacing+Beat

 

Also: From Mazda Competition,

 

 

Lynn E. Hanover  

 

 

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