Mailing List flyrotary@lancaironline.net Message #30430
From: Chuck Dunlap <crayd@cableone.net>
Subject: RE: [FlyRotary] Re: Rotor identification
Date: Sat, 25 Feb 2006 20:23:36 -0700
To: 'Rotary motors in aircraft' <flyrotary@lancaironline.net>
Message
 
-----Original Message-----
From: Rotary motors in aircraft [mailto:flyrotary@lancaironline.net] On Behalf Of Russell Duffy
Sent: Saturday, February 25, 2006 6:09 PM
To: Rotary motors in aircraft
Subject: [FlyRotary] Re: Rotor identification

I bought this pair of used rotors to build up a new motor so I can retrieve my RV-6. They look different in the compression chamber "tub" area, otherwise they look identical. They both are marked "D" for the weight code. Can anyone identify these and verify if they are OK to use ? I am thinking if the compression ratio is different, it may run rough even if they weigh the same. I remember Ed posting something about a way to measure the depth, but I cannot find it in my sea of saved emails. 
 
Hi Chuck,
 
As you probably know, the rotors you use must also match the counterweights that you have.  What year, and CR rotors do you have in the current engine?
 
Overall weight of the rotors will tell the tale for counterweights, and will also narrow down the CR identification to only two choices per rotor weight.  Attached is the weight and CR chart that I "borrowed" from Mazdatrix's site.   
 
Do you have the old engine at home, or are you planning to build a new engine, then swap them in one trip? 
 
Good luck.  
 
Rusty (8 days RV-8 construction, finishing empennage kit tomorrow)  
 
Thanks for reminding of that, Rusty - I was thinking of using the high compression rotors but I will have to wait until I can find the late model counterweights to match, I will use the low compression ones instead. I have had two motors, both are 1986 series 4 with the 9.4 CR rotors. I plan to build up one motor out of the good parts that I have, and drive it to Texas and swap it out on site. I will hopefully fly the RV6 back, and my brother will drive the truck back with the bad motor. I have swapped motors enough times that I think I can easily do it in one day.
Chuck
Subscribe (FEED) Subscribe (DIGEST) Subscribe (INDEX) Unsubscribe Mail to Listmaster