Al Gietzen wrote:

Dale Thomas wrote:

I will be building a Velocity XL-RG and was planning on
using a Lyc IO-540 300hp engine.  Is the Mazda engine
of that hp able to run in a pusher config?  Do you know
if anyone has ever tried it?

We have had two Velocity type airplanes fly with turbo three rotor
Mazda engines so far. Many other airplanes are in the works with
the turbo three rotor. The engine is good for about 350 HP no problem.
Nobody has run one very hard yet but I will guess and say 400 HP
should be no problem for take off. If you don't want to go turbo
270 HP is no problem. The bare engine weight is about 260 pounds.
My guess firewall forward with everything would be about 350 to 400
pounds.

Dale;

I think the 20B is an ideal choice for the XL.  I am installing a NA 20B in
my Standard Velocity RG.  Except for electrical and other details I have the
complete installation on the the airplane, and there is no problem with room
in the cowling.  In fact, I am making a custom cowling taking off the side
bulges that are there to accomodate the Lycoming 360.  With the larger
cowling on the XL you would have plenty of room for a turbo and intercooler
if you choose to go that route.

Paul is just a tad optimistic on the weight.  I went as light as possible
(custom intake and exhaust manifold, oil pan etc); and the all-up weight is
403 lbs including estimated weights for plumbing.  Add about 24 lbs for
coolant.  I have two custom radiators, one in the cowling and one in the
wing root.  The custom oil cooler is in the other wing root.

This is not much heavier than an IO360 installation, and I estimate the CG a
couple of inches further forward than the Lyc, resulting in a moment for the
engine package that is very close to being the same.  Definitely lighter
than IO 540.

Al Gietzen

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