X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from qw-out-2122.google.com ([74.125.92.26] verified) by logan.com (CommuniGate Pro SMTP 5.2.12) with ESMTP id 3523322 for flyrotary@lancaironline.net; Mon, 02 Mar 2009 10:09:21 -0500 Received-SPF: pass receiver=logan.com; client-ip=74.125.92.26; envelope-from=rwstracy@gmail.com Received: by qw-out-2122.google.com with SMTP id 8so1854316qwh.25 for ; Mon, 02 Mar 2009 07:08:44 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma; h=domainkey-signature:mime-version:sender:received:in-reply-to :references:date:x-google-sender-auth:message-id:subject:from:to :content-type; bh=eZYWq30c45AkDc2pIs6oIXfm7npWplSziSXycztHCA4=; b=RMU+nOoHkNvxeePm7QJRpqDEng0Qb+6/SV/MmLVo7wpBXZiml52h7tpuhP2TWJhlUx Hs/xf0sN0xYPCpdCrFs3GOKDU2jGCPFBGeu6K7EzV2/7VHXtlkoa5HQGjeTylPZzKU86 thK+pIBcRzces78710Q4mflapu5gghI5Yp5tk= DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=mime-version:sender:in-reply-to:references:date :x-google-sender-auth:message-id:subject:from:to:content-type; b=LJFjeKlTR1r66vD3OPzdScyVkFWJWGRboaeWFBRyw1xj60P/29UJY8rHcjBZFhUJTl PEfhKtpvZaTz5K+FhcsOl+wb3J2cEaCYOBhid0cvhFTXPP2jLTj96ZWWpe972s3KAfQ8 vJrqgV5ynR+Sz92jLpIegheUrDd0r2Vi0hsjs= MIME-Version: 1.0 Sender: rwstracy@gmail.com Received: by 10.224.89.75 with SMTP id d11mr7629869qam.274.1236006523962; Mon, 02 Mar 2009 07:08:43 -0800 (PST) In-Reply-To: References: Date: Mon, 2 Mar 2009 10:08:43 -0500 X-Google-Sender-Auth: e2eb3e3344701dc4 Message-ID: <1b4b137c0903020708t7f0b75earb95a76f99f848d05@mail.gmail.com> Subject: Re: [FlyRotary] Re: Missing Key From: Tracy Crook To: Rotary motors in aircraft Content-Type: multipart/alternative; boundary=0015175ccf2ecd05070464243111 --0015175ccf2ecd05070464243111 Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: quoted-printable Not sure how long that would take to set up but maybe super glue? Then, if you get the alignment of the key off even a little, the pump drive pulley won't fit. The pro engine builders I know put a little dimple in the key with a punc= h that makes it a light press fit in the groove. That way it doesn't slide out easily during assembly. Worked well for me on my last 20B assembly. Tracy On Mon, Mar 2, 2009 at 9:45 AM, Dale Rogers wrote: > Folks, > > Is there any good reason to _not_ locktite (red) the key > into the pump shaft groove? > > Dale R. > > Ed Anderson wrote: > >> >> Very good point, Tom. >> >> Don=92t know how I could have forgotten the problem I had with the key f= or >> the oil pump shaft. In fact, I flew for 10 hours with the key missing = =96 only >> the clamping force of the nut on the shaft holding the gear to the shoul= der >> of the shaft. While at Shady Bend (Tracy Crook), I unintentionally left = my >> throttle at full open after we had comparing throttle bodies and intakes= . >> >> The next morning was a bit cool and I was using 50 weight oil. I hopped >> into go do some flying with Tracy and Finn Lassen, when I fired up the >> engine (Having forgotten to close the throttle from the previous days >> inspection), the engine caught and immediately zoomed to 5000 rpm before= I >> could hastily pull the throttle back. I noticed lower than normal (aroun= d >> 20-25 psi) oil pressure while taxing to take off and just told myself it= was >> the cold weather, cranky sensor or gauge, but by the time I got to take = off >> position, I notice the oil pressure had never gotten above 25 psi when >> normally at taxi rpm I would have around 40-50 psi. >> >> Fortunately, I could not bring myself to take off with that condition >> (even though I kept telling myself there was nothing wrong). After much >> trouble shooting, I decided I had to pull the engine off (thankfully, Tr= acy >> Crook had a great facility to do that in) . I removed the oil pan and as= I >> took it over to wash it out, I hear a metallic clanking in the pan =96 y= es, >> you know what it was =96 a much battered key for the oil pump shaft. Whe= n I >> had pushed the sprocket on the shaft, I had pushed out the key but >> unfortunately, it did not drop down. It got trapped between the sprocket >> wheel and the soft aluminum oil pump housing (the indention was in the s= oft >> aluminum) from the force torquing the nut down. This had push the sprock= et >> against the trapped key which in turn had pushed the key against the hou= sing >> and trapped it there =96 probably until the first engine run. Fortunatel= y, I >> had torqued the nut down as specified =96 which some folks think is a bi= t high >> for that small a nut, but glad I had. I=92m also glad in hind sight I le= ft the >> throttle open and it was a cool morning =96 who knows when it might have= let >> go. >> >> So now when I rebuild an engine, I take a small paper clip and bend the >> end out so I can stick it in the keyway hole after putting the sprocket = on. >> If it goes in all the way =96 the key is not in its slot! >> >> Moral of the story, it can happen to any of us =96 so take time and chec= k. >> As Tom mentioned, it can be a bit of a hassle to get the keyway in the s= lot >> and sprocket on =96 if it falls out (as it will most of the time) and yo= u hear >> it/see it you are OK. But, if it gets trapped as my key did =96 you won= =92t get >> that clue. So use a paper clip, inspection or something to insure the ke= y is >> where you think it is. >> >> Also pay attention to your gauges and your gut they are both always >> telling you something =96 if you will only listen {:>) >> >> Ed >> >> > > > -- > Homepage: http://www.flyrotary.com/ > Archive and UnSub: > http://mail.lancaironline.net:81/lists/flyrotary/List.html > --0015175ccf2ecd05070464243111 Content-Type: text/html; charset=windows-1252 Content-Transfer-Encoding: quoted-printable Not sure how long that would take to set up but maybe super glue?=A0 Then, = if you get the alignment of the key off even a little, the pump drive pulle= y won't fit.

=A0 The pro engine builders I know put a little di= mple in the key with a punch that makes it a light press fit in the groove.= =A0 That way it doesn't slide out easily during assembly.=A0=A0 Worked = well for me on my last 20B assembly.

Tracy

On Mon, Mar 2, 2009 at 9:45 AM,= Dale Rogers <dale.r= @cox.net> wrote:
Folks,

Is there any good reason to _not_ locktite (red) the key
into the pump shaft groove?

Dale R.

Ed Anderson wrote:

Very good point, Tom.

Don=92t know how I could have forgotten the problem I had with the key for = the oil pump shaft. In fact, I flew for 10 hours with the key missing =96 o= nly the clamping force of the nut on the shaft holding the gear to the shou= lder of the shaft. While at Shady Bend (Tracy Crook), I unintentionally lef= t my throttle at full open after we had comparing throttle bodies and intak= es.

The next morning was a bit cool and I was using 50 weight oil. I hopped int= o go do some flying with Tracy and Finn Lassen, when I fired up the engine = (Having forgotten to close the throttle from the previous days inspection),= the engine caught and immediately zoomed to 5000 rpm before I could hastil= y pull the throttle back. I noticed lower than normal (around 20-25 psi) oi= l pressure while taxing to take off and just told myself it was the cold we= ather, cranky sensor or gauge, but by the time I got to take off position, = I notice the oil pressure had never gotten above 25 psi when normally at ta= xi rpm I would have around 40-50 psi.

Fortunately, I could not bring myself to take off with that condition (even= though I kept telling myself there was nothing wrong). After much trouble = shooting, I decided I had to pull the engine off (thankfully, Tracy Crook h= ad a great facility to do that in) . I removed the oil pan and as I took it= over to wash it out, I hear a metallic clanking in the pan =96 yes, you kn= ow what it was =96 a much battered key for the oil pump shaft. When I had p= ushed the sprocket on the shaft, I had pushed out the key but unfortunately= , it did not drop down. It got trapped between the sprocket wheel and the s= oft aluminum oil pump housing (the indention was in the soft aluminum) from= the force torquing the nut down. This had push the sprocket against the tr= apped key which in turn had pushed the key against the housing and trapped = it there =96 probably until the first engine run. Fortunately, I had torque= d the nut down as specified =96 which some folks think is a bit high for th= at small a nut, but glad I had. I=92m also glad in hind sight I left the th= rottle open and it was a cool morning =96 who knows when it might have let = go.

So now when I rebuild an engine, I take a small paper clip and bend the end= out so I can stick it in the keyway hole after putting the sprocket on. If= it goes in all the way =96 the key is not in its slot!

Moral of the story, it can happen to any of us =96 so take time and check. = As Tom mentioned, it can be a bit of a hassle to get the keyway in the slot= and sprocket on =96 if it falls out (as it will most of the time) and you = hear it/see it you are OK. But, if it gets trapped as my key did =96 you wo= n=92t get that clue. So use a paper clip, inspection or something to insure= the key is where you think it is.

Also pay attention to your gauges and your gut they are both always telling= you something =96 if you will only listen {:>)

Ed




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