X-Mozilla-Keys:                                                                                 
Ken Powell wrote:

     First of all, I would like to give my thanks to Alan Tolle for sharing
     this info with us.  He really made an impression on me.  The following
     is  a summation of how I remember his posts on this issue.

     Todays messages on RV-4 cooling reminded me of the W & B posts of
     about 6 months ago where Alan stated that a rotary engine needs to be
     mounted about 6.5 inches further forward (from firewall to prop
     flange) than a o-320 Lyncoming.  I don't have my notes with me at the
     office, but the following is what I remember of Alan's post.  Alan
     included the oil, oil cooler, hoses, and engine mount in his
     calculations.  I definitely remember Alan stating that if the rotary
     is mounted with the same prop flange location as the o-320 the center
     of gravity moved aft 3.5 INCHES.  If the airplane were fully loaded (I
     don't remember how he defined this) then the center of gravity would
     be behind the aft limit after a long cross country flight (I think he
     said a 3.5 hr flight).  This is known to be a very dangerous condition
     for the RV's that Van's often warns against.

     I am rather puzzled why we have not had more builders state that they
     were going to move the engine forward.  Alan is an experienced builder
     who knows what he is talking about.  I did my own weight and balance
     and I came out with a move of 6 inches forward.  I think that I
     allowed 30 lbs for radiators, hoses and coolant located an average of
     14 inches forward of the firewall.  I realize that the cowling will
     need to be extended, but the advantages should make it worth it.
     1.  bring the weight and balance within range
     2.  give lots of extra room

     If I have this info wrong, someone please correct me.  The above is
     only what I think that I remember, not what was actually posted.  If I
     ever get to the firewall forward, this is how I'm going to configure
     the mounting of the engine.

     Thanks,
     Ken Powell

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