Return-Path: Received: from [24.25.9.102] (HELO ms-smtp-03-eri0.southeast.rr.com) by logan.com (CommuniGate Pro SMTP 4.2.5) with ESMTP id 595292 for flyrotary@lancaironline.net; Fri, 07 Jan 2005 21:55:23 -0500 Received-SPF: none receiver=logan.com; client-ip=24.25.9.102; envelope-from=eanderson@carolina.rr.com Received: from edward2 (cpe-069-132-111-212.carolina.rr.com [69.132.111.212]) by ms-smtp-03-eri0.southeast.rr.com (8.12.10/8.12.7) with SMTP id j082sokd010312 for ; Fri, 7 Jan 2005 21:54:52 -0500 (EST) Message-ID: <000c01c4f52d$6ffd6f30$2402a8c0@edward2> From: "Ed Anderson" To: "Rotary motors in aircraft" References: Subject: Re: [FlyRotary] Re: Oil Pump Drive Key was Re: [FlyRotary] Re: Some things to check Date: Fri, 7 Jan 2005 21:54:56 -0500 MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_0009_01C4F503.86D66100" 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 X-Virus-Scanned: Symantec AntiVirus Scan Engine This is a multi-part message in MIME format. ------=_NextPart_000_0009_01C4F503.86D66100 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Wendel, One suggestion I have is to bend a paper clip so that an leg is = sticking straight out (or any other such) then insert it into the = keyway. I forget now but I think it should not go in much more than = 1/4" IF the key is present, I'll check on a pump I have in the shop = tomorrow. If you find the paper clip going in more than 1/2" (I'll = check tomorrow) you key is likely missing. Further amplification on what Leon said about the key - it is easier = than you may think to put the key in the keyway and slide the sprocket = on the shaft and push the keyway out. Normally when that happens you = hear the "ping" as the metal key hits the floor. But in this case, It = appears that when I push the key out the back side as I slid on the = sprocket, I actually clamped the key between the sprocket and the pump = housing. The reason I am confident that is what happened is the mark of = the key was impressed into the soft aluminum housing. The first spin = of the sprocket then threw the key into the bottom of the pan. Fortunately I had torqued the nut to the books specs (which many think = is a bit high for that small a nut) and flew with it for 10 hours. One = evening when I was at Tracy's we were looking into the throttle bodies = and I had push my throttle in all the way to open the butterfly. Forgot = to close it. Next more was cool and when I started the engine it = immediately (wide open throttle ) fired and zoomed to 5000 rpm with cold = 50 weight oil. That broke the clamp of the nut and it started to turn = the sprocket faster than the shaft and actually wore a small circular = place around the sprocket shaft as it rubbed against the shoulder of the = shaft. Tracy, Finn and I were going flying. A very lite breeze from the north, = but Tracy and Finn elected to take off to the south. Unless an unusual = situation exists, I always take off into the wind, so I elected to taxi = to the south end for my up wind take off. One the way taxing I noticed = that my oil pressure was only reading 20 psi when it normally reads 30 - = 50 psi.=20 I tried telling myself it must be a bad sensor or gauge and nothing was = really wrong, but I just couldn't ignore that anomaly and decided to = abort the take off and taxied back to the hangar. Fortunate decision as = I doubt the oil pressure would have stayed as high as 20 psi had I = decided to fly. After much "try this, try that" it finally because apparent the engine = would have to come off. Tracy's is the best place in the world (other than perhaps your home = hangar) to have a problem. He had a replacement oil pump and helped me = get it all back together using his hangar for my repair. A great place = to have to spend time down for repair. FWIW. Ed Anderson ----- Original Message -----=20 From: Wendell Voto=20 To: Rotary motors in aircraft=20 Sent: Friday, January 07, 2005 7:22 PM Subject: [FlyRotary] Re: Oil Pump Drive Key was Re: [FlyRotary] Re: = Some things to check ----- Original Message -----=20 From: Leon=20 To: Rotary motors in aircraft=20 Sent: Friday, January 07, 2005 2:46 PM Subject: [FlyRotary] Oil Pump Drive Key was Re: [FlyRotary] Re: Some = things to check=20 Wendell, Ed Anderson had a problem where the oil pump Wooodruff key wasn't in = the keyway. The drive was just taken by the friction of the tensioned = nut. Worked for a while. Sooner or later, the sprocket will slip on the = shoulder of the pump shaft. The symptom is intermittent loss of oil = pressure, which gets worse as the sprocket wears on the shaft shoulder. So, as I said in the post below, always make sure that the key is = actually in the keyway before fitting to nut & lockwasher. The key = itself is very tiny, and it requires a bit of juggling to get it in the = keyway in the sprocket. I normally gently stake the keyway in the shaft = so that the key can't slip out. Hope this makes sense! Leon Thanks Leon, can proper installation be checked by inspection or = do you have to remove the pump and start over? Wendell ------=_NextPart_000_0009_01C4F503.86D66100 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable
Wendel,  One suggestion I have is = to bend a=20 paper clip so that an leg is sticking straight out (or any other such) = then=20 insert it into the keyway.  I forget now but I think it should not = go in=20 much more than 1/4" IF the key is present, I'll check on a pump I have = in the=20 shop tomorrow.  If you find the paper clip going in more than 1/2" = (I'll=20 check tomorrow) you key is likely missing.
 
Further amplification on what Leon said = about the=20 key - it is easier than you may think to put the key in the keyway and = slide the=20 sprocket on the shaft and push the keyway out. Normally when that = happens=20 you hear the "ping" as the metal key hits the floor.  But in this=20 case, It appears that when I push the key out the back side as I = slid on=20 the sprocket, I actually clamped the key between the sprocket and the = pump=20 housing.  The reason I am confident that is what happened is the = mark of=20 the  key was impressed into the soft aluminum housing.  The = first spin=20 of the sprocket then threw the key into the bottom of the = pan.
 
Fortunately I had torqued the nut to = the books=20 specs (which many think is a bit high for that small a nut) and flew = with it for=20 10 hours.  One evening when I was at Tracy's we were looking into = the=20 throttle bodies and I had push my throttle in all the way to open the=20 butterfly.  Forgot to close it.  Next more was cool and when I = started=20 the engine it immediately (wide open throttle ) fired and zoomed to 5000 = rpm=20 with cold 50 weight oil.  That broke the clamp of the nut and it = started to=20 turn the sprocket faster than the shaft and actually wore a small = circular place=20 around the sprocket shaft as it rubbed against the shoulder of the=20 shaft.
 
Tracy, Finn and I were going = flying.  A very=20 lite breeze from the north, but Tracy and Finn elected to take off to = the=20 south.  Unless an unusual situation exists, I always take off into = the=20 wind, so I elected to taxi to the south end for my up wind take = off.  One=20 the way taxing I noticed that my oil pressure was only reading 20 psi = when it=20 normally reads 30 - 50 psi.
I tried telling myself it must be a bad = sensor or=20 gauge and nothing was really wrong, but I just couldn't ignore that = anomaly and=20 decided to abort the take off and taxied back to the hangar.  = Fortunate=20 decision as I doubt the oil pressure would have stayed as high as 20 psi = had I=20 decided to fly.
 
  After much "try this, try that" = it finally=20 because apparent the engine would have to come off.
 
Tracy's is the best place in the world = (other than=20 perhaps your home hangar) to have a problem.  He had a replacement = oil pump=20 and helped me get it all back together using his hangar for my = repair.  A=20 great place to have to spend time down for repair.
 
FWIW.
 
Ed Anderson
 
 
 
 
 
----- Original Message -----
From:=20 Wendell = Voto=20
Sent: Friday, January 07, 2005 = 7:22=20 PM
Subject: [FlyRotary] Re: Oil = Pump Drive=20 Key was Re: [FlyRotary] Re: Some things to check

 
----- Original Message -----
From:=20 Leon=20
To: Rotary motors in = aircraft=20
Sent: Friday, January 07, = 2005 2:46=20 PM
Subject: [FlyRotary] Oil Pump = Drive Key=20 was Re: [FlyRotary] Re: Some things to check

Wendell,
 
Ed Anderson had a problem where the = oil pump=20 Wooodruff key wasn't in the keyway.  The drive was just taken = by the=20 friction of the tensioned nut. Worked for a while. Sooner = or=20 later,  the sprocket will slip on the shoulder of the pump = shaft. =20 The symptom is intermittent loss of oil pressure,  which gets = worse as=20 the sprocket wears on the shaft shoulder.
 
So,  as I said in the post = below, =20 always make sure that the key is actually in the keyway before = fitting to=20 nut & lockwasher.  The key itself is very tiny,  and = it=20 requires a bit of juggling to get it in the keyway in the = sprocket.  I=20 normally gently stake the keyway in the shaft so that the key can't = slip=20 out.
 
Hope this makes sense!
 
Leon
Thanks Leon, can proper = installation be=20 checked by inspection or do you have to remove the pump and start=20 over?
Wendell
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