X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from cdptpa-omtalb.mail.rr.com ([75.180.132.121] verified) by logan.com (CommuniGate Pro SMTP 5.2.0) with ESMTP id 2750379 for flyrotary@lancaironline.net; Wed, 20 Feb 2008 19:26:39 -0500 Received-SPF: pass receiver=logan.com; client-ip=75.180.132.121; envelope-from=eanderson@carolina.rr.com Received: from edward2 ([75.191.190.141]) by cdptpa-omta06.mail.rr.com with SMTP id <20080221002558.JMEQ13780.cdptpa-omta06.mail.rr.com@edward2> for ; Thu, 21 Feb 2008 00:25:58 +0000 Message-ID: <002f01c87420$58f8e060$2402a8c0@edward2> From: "Ed Anderson" To: "Rotary motors in aircraft" References: Subject: Oil pump nut torque [FlyRotary] Re: Rebuild kit Date: Wed, 20 Feb 2008 19:26:05 -0500 MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_002C_01C873F6.6FEE5AE0" X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 6.00.2900.3138 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2900.3198 This is a multi-part message in MIME format. ------=_NextPart_000_002C_01C873F6.6FEE5AE0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Good point, Jim Also the nut on the sprocket takes a lot more torque per spec than you = might think from its size. Do torque it to specs - When I rebuilt my = engine, I unknowingly pushed the shaft key out and pinned it between = the sprocket and the aluminum pump housing - so it did not fall to the = floor and warn me. I flew 10 hours with the key missing - the proper = torque kept the sprocket from spinning on the shaft. However, at Tracy Crooks, Finn Lassen and I were comparing intakes and I = left my throttle pushed full open. Next morning we were going to = measure exhaust loudness - you guessed it - when I fired up on this = cool 50F morning my engine immediately revved to 5000 rpm before I could = get it shut down. Did I mention I use 50 weigh oil?? During taxi to the far end of the runway (because I was a wimp and would = not take off down wind even thought it was only a less than 5 mph = breeze) I noticed my oil pressure was on the low side like around 20 = psi. That caught my attention. Even when I revved the engine it did = not go much above that - must be the sensor or the gauge - right? = Well, I could not bring my self to take off even though I "knew" it has = to be the sensor or gauge. Well, you know the answer, when I disassembled the engine at Tracys I = found the beat up key in the bottom of the oil pan. I also discovered = the impression in the soft aluminum oil pump housing where tightening = the sprocket nut had pushed it - until after I had buttoned up the = engine and ran it the first time. The immediate zoom to 5000 rpm on a = cool morning undoubtedly was too much torque for the nut alone to hold = against. When I examined the sprocket, the shoulder of the pump shaft = had started to wear a grove in the sprocket. A few more turns and I = probably would not have been able to get 20 psi. Fortunately, Tracy = had a lot of replacement parts including an oil pump. Soooo the message is make certain that key is in there. I use a paper = clip bending out one leg - if it goes in more than 1/4" that key is not = in the slot. It turns out I was not the first to have this happen - for = the key to get pushed out. But, apparently no body else flew that way = {:>)_ Ed ----- Original Message -----=20 From: James Maher=20 To: Rotary motors in aircraft=20 Sent: Wednesday, February 20, 2008 6:34 PM Subject: [FlyRotary] Re: Rebuild kit Ernest, While you have the oil pump drive exposed it would be a good idea to = assure that the nut that holds the drive sprocket on the pump has the locking = washer installed properly. Mine did not, and it only took about 8 hours of run time for the = sprocket to fall off and chew a hole in the cover. Jim Ernest Christley wrote: Lehanover@aol.com wrote: > So now the chain is too long, but it has no affect on performance. = The spec=20 > is for droop when the chain is off the engine and held side ways = to check for=20 > wear in the link joints. Still doesn't matter. Even warn out they = work just=20 > fine. Up to 115 pounds of oil pressure. There is a tiny hole in = the pump that=20 > sprays lube oil into the pulley to lube the chain. Have never seen = one break=20 > since 1980. >=20 > Lynn E. Hanover > >=20 Thanks, Lynn.=20 Woohoo! One part down. 64 more to go 8*) --=20 http://www.ronpaultimeline.com -- Homepage: http://www.flyrotary.com/ Archive and UnSub: = http://mail.lancaironline.net:81/lists/flyrotary/List.html ------=_NextPart_000_002C_01C873F6.6FEE5AE0 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable
Good point, Jim
 
Also the nut on the sprocket takes a lot more = torque per=20 spec than you might think from its size.  Do torque it  to = specs -=20 When I rebuilt my engine, I unknowingly  pushed the shaft key out = and=20 pinned it between the sprocket and the aluminum pump housing - so it did = not=20 fall to the floor and warn me.  I flew 10 hours with the key = missing - the=20 proper torque kept the sprocket from spinning on the shaft.
 
However, at Tracy Crooks, Finn Lassen and I were = comparing=20 intakes and I left my throttle pushed full open.   Next = morning we=20 were going to measure exhaust loudness - you guessed it -  when I = fired up=20 on this cool 50F morning my engine immediately revved to 5000 rpm before = I could=20 get it shut down.  Did I mention I use 50 weigh oil??
 
During taxi to the far end of the runway = (because I was a=20 wimp and would not take off down wind even thought it was only a less = than 5 mph=20 breeze) I noticed my oil pressure was on the low side like around 20 = psi. =20 That caught my attention.  Even when I revved the engine it did not = go much=20 above that - must be the sensor or the gauge - right?    = Well, I=20 could not bring my self to take off even though I "knew" it has to be = the sensor=20 or gauge.
 
Well, you know the answer, when I disassembled = the engine=20 at Tracys I found the beat up key in the bottom of the oil pan.  I = also=20 discovered the impression in the soft aluminum oil pump housing where = tightening=20 the sprocket nut had pushed it - until after I had buttoned up the = engine and=20 ran it the first time.  The immediate zoom to 5000 rpm on a cool = morning=20 undoubtedly was too much torque for the nut alone to hold against.  = When I=20 examined the sprocket, the shoulder of the pump shaft had started to = wear a=20 grove in the sprocket.  A few more turns and I probably would not = have been=20 able to get 20 psi.   Fortunately, Tracy had a lot of = replacement=20 parts including an oil pump.
 
Soooo the message is make certain that key is in = there.  I use a paper clip bending out one leg - if it goes in more = than=20 1/4" that key is not in the slot.  It turns out I was not the first = to have=20 this happen - for the key to get pushed out.  But, apparently no = body else=20 flew that way {:>)_
 
Ed
----- Original Message -----
From:=20 James = Maher=20
Sent: Wednesday, February 20, = 2008 6:34=20 PM
Subject: [FlyRotary] Re: = Rebuild=20 kit

Ernest,
While you have the oil pump drive exposed it would be a good idea = to=20 assure
that the nut that holds the drive sprocket on the pump has the = locking=20 washer
installed properly.
Mine did not, and it only took about 8 hours of run time for the = sprocket=20 to fall off
and chew a hole in the cover.
Jim

Ernest Christley <echristley@nc.rr.com>= =20 wrote:
Lehanover@aol.com=20 wrote:
> So now the chain is too long, but it has no affect on = performance. The spec
> is for droop when the chain is off = the engine=20 and held side ways to check for
> wear in the link joints. = Still=20 doesn't matter. Even warn out they work just
> fine. Up to = 115 pounds=20 of oil pressure. There is a tiny hole in the pump that
> = sprays lube=20 oil into the pulley to lube the chain. Have never seen one break =
>=20 since 1980.
>
> Lynn E. Hanover
>
> =
Thanks,=20 Lynn.
Woohoo! One part down. 64 more to go 8*)

--=20 =

http://www.ronpaultimeline.com



--
Homepage:=20 http://www.flyrotary.com/
Archive and UnSub:=20 = http://mail.lancaironline.net:81/lists/flyrotary/List.html

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