Here are the prices of the parts you will need. None of the existing
  2.17 parts are usable.

  Prop Shaft - $670.00
  prop shaft front bearing 35.00
  prop shaft bearing keeper 18.00
  Planet carrier & gears 120.00
  sun gear 50.00
  sun gear shaft 55.00
  ring gear & bulkhead 70.00
  planet carrier thrust bearing 20.00
  input shaft thrust bearing 45.00
  input shaft pilot bearing 12.00
  shipping cost TBD

  I can not furnish directions for performing this conversion.

  Tracy Crook, RWS


  Tracey con I buy the needed parts as I have access to machine shop
  If I don't change I will have to change motor mount and prop
  Thanks Keith


  Keith,
  It is not easy to make this conversion since it is not just a
  matter of changing parts. I did one and it was simply too labor
  intensive to be practical. I flew the 2.17 drive for many years
  on my RV and it worked nicely so it is not absolutely necessary
  to make this change.

  All the best,
  Tracy Crook, RWS


  Laura or Tracey I have a 2.17 redrive can I get the parts to
  convert to 2.8 I am building RV7 with 13B Mazda Need help
  Thanks Keith Menard

  Paul Lamar
  Sorry for the long time for me to get back as work keeps me away Here
  is list of parts Tracey said I will need do you think I can safely lock
  ring gear or am I wasting my time and money and just buy new 2.85
  redrive or has anyone done such conversion?

  Next question does your plans for engine mount give tube length to help
  setting up to cut as all I have read I should scrap my engine mount
  because of heat on engine mount ?

  Thanks Keith


  I think it is doable. It may take a sleeve pressed and welded
  in the main casting to lock the ring gear. I don't recall anybody doing
  it so far however. You might have trouble selling the 2.i7 due to the
  economy right at the moment. It is more important to have a 2.85 if
  you also have a p-port engine. If not your engine RPM will be limited
  anyway due to prop diameter.

  What kind of engine mount do you have now?

  Yes our dwgs give the tube lenght. It is best if you have something
  like 2D Q Cad so we can send you a dxf and you can then use Qcad to get
  any dimension. Try that approach first. If that does not work we can
  do something else.

  Here is the Schertz beam version MM for the RV7 which is your kit of
  chioce
  as I recall. I will revise it for Jeff's motor plate if you wish.

  Paul Lamar

  Paul Lamar  The mount I have is the plate between the engine and oil
  pan  I would like to change to Jeff's motor plate I should -might be
  able to remove all the forward tubes except for the nosewheel mount
  and build from that I can build a jig sim to firewall and motor
  position spaced off firewall for a jig
  I do not have Qcad or any sim program  Would be willing to pay
  shipping and for plans as needed
  Thank you Keith--

Well that will work.

OK I'll have to do a new mount for an RV7A. No problem.

BTW here is a refinement on the motor mount jig.
Use Jeff's plate amd mount a laser in the center of the hole
to put a spot on the firewall.

Paul Lamar