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High time Remaster engine

Dave Dugas
 


I discovered, for the second time, a broken wavy spring washer on the rocker shaft assembly. Both times the washers were in 2 pieces, and all the pieces were located. The first time it happened I replaced the broken washer with a used one, and ordered a new set along with the rocker shaft clips. While replacing them today I discovered that one more had broken in one spot, so it was still in one piece. All that I noticed in hindsight when flying while the broken washer was still undiscovered, was a very slight difference in the sound. Barely noticeable. So.... I would recommend that once you get up in hours, replace them and the clips. Cheap insurance as I suspect metal fatigue can eventually occur. All good now with the new parts for another 1000 hours. Hope to see everyone in Enid at the FOD reunion. Dave D...1250 hours.
Bruce Crain
 

Whew!  Good thorough check!
B


On Aug 25, 2021, at 12:42 PM, Dave Dugas via groups.io <davedq2@...> wrote:


<IMG_20210825_131254113.jpg>

I discovered, for the second time, a broken wavy spring washer on the rocker shaft assembly. Both times the washers were in 2 pieces, and all the pieces were located. The first time it happened I replaced the broken washer with a used one, and ordered a new set along with the rocker shaft clips. While replacing them today I discovered that one more had broken in one spot, so it was still in one piece. All that I noticed in hindsight when flying while the broken washer was still undiscovered, was a very slight difference in the sound. Barely noticeable. So.... I would recommend that once you get up in hours, replace them and the clips. Cheap insurance as I suspect metal fatigue can eventually occur. All good now with the new parts for another 1000 hours. Hope to see everyone in Enid at the FOD reunion. Dave D...1250 hours.

<IMG_20210825_131254113.jpg>
gmkonrad
 

Hi Dave, 
I lost a rocker arm clip on my Dragonfly years ago, flying from Kentucky to Michigan.  It was on an exhaust valve and the rocker arm was hammering on the valve spring retainer.  Still enough power to stay in the air, but it shook quite a bit.  Landed, was able to find a replacement part, and continued home.  I was able to machine my own spacers and end caps for the rocker arm shafts.  Also the shafts can be drilled and tapped on the ends for the retaining bolts.  No problems in several hundred hours since.  I highly recommend it.
 
Gary
Dragonfly N19GK
Dave Dugas
 

Hi Gary
Thanks for the reply. Fortunately I almost never noticed any vibration. It was one of the spring washers that keeps the rocker arms centered on the valve stem, not one of the clips. Maybe next time that you are working on it you could take a picture for me. Sounds like a solid fix. 
Dave D


On Thu, Aug 26, 2021 at 2:31 PM, gmkonrad via groups.io
<gmkonrad@...> wrote:
Hi Dave, 
I lost a rocker arm clip on my Dragonfly years ago, flying from Kentucky to Michigan.  It was on an exhaust valve and the rocker arm was hammering on the valve spring retainer.  Still enough power to stay in the air, but it shook quite a bit.  Landed, was able to find a replacement part, and continued home.  I was able to machine my own spacers and end caps for the rocker arm shafts.  Also the shafts can be drilled and tapped on the ends for the retaining bolts.  No problems in several hundred hours since.  I highly recommend it.
 
Gary
Dragonfly N19GK
One Sky Dog
 

Dave,


Here is your solution to broken wavy springs.

On Thursday, August 26, 2021, 9:07 PM, Dave Dugas via groups.io <davedq2@...> wrote:

Hi Gary
Thanks for the reply. Fortunately I almost never noticed any vibration. It was one of the spring washers that keeps the rocker arms centered on the valve stem, not one of the clips. Maybe next time that you are working on it you could take a picture for me. Sounds like a solid fix. 
Dave D


On Thu, Aug 26, 2021 at 2:31 PM, gmkonrad via groups.io
<gmkonrad@...> wrote:
Hi Dave, 
I lost a rocker arm clip on my Dragonfly years ago, flying from Kentucky to Michigan.  It was on an exhaust valve and the rocker arm was hammering on the valve spring retainer.  Still enough power to stay in the air, but it shook quite a bit.  Landed, was able to find a replacement part, and continued home.  I was able to machine my own spacers and end caps for the rocker arm shafts.  Also the shafts can be drilled and tapped on the ends for the retaining bolts.  No problems in several hundred hours since.  I highly recommend it.
 
Gary
Dragonfly N19GK
gmkonrad
 

Charlie has posted what I had been thinking about.  I thought I had included that link, put a computer issue messed with my comment.   I duplicated the store bought parts on my own.  As you have found, the wave washers are prone to breaking, eventually so are the spring clips.

Gary
Dave Dugas
 

Thanks Charlie and Gary. I'll order that high performance rocker shaft and see how it goes next time I change the oil and plugs. Looks like they eliminate the clips all together.
Dave D


On Fri, Aug 27, 2021 at 1:13 PM, gmkonrad via groups.io
<gmkonrad@...> wrote:
Charlie has posted what I had been thinking about.  I thought I had included that link, put a computer issue messed with my comment.   I duplicated the store bought parts on my own.  As you have found, the wave washers are prone to breaking, eventually so are the spring clips.

Gary
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