Chris Wilson wrote:

I have a friend that is putting a 20B turbo in a Lance Air ES and he has
talked me into a 13B fuel injected non turbo for a RV-9A.  I have
noticed the plugs up on some of the engines and some are mounted like
they sit in the car.  What is the advantage of a plugs up install?  The
cleanest install that I have seen was on a RV-6A (plugs up).  Thanks.

Fly Safe,
Chris Wilson

There are no advantages since the tall distributor was done away with
15 years ago. In fact there are many disadvantages. The engine was

designed

to be run upright.

Paul Lamar

 Ok Rotarians,

I'm sure that this is a well worn path on this news group, but since I
haven't been on here for that long, I would also like to see a discussion on
this subject. My personal understanding of the subject is that the plugs up
arrangement results in problems with oil return. I have also heard several
people talk about steam pockets. Given the recent discussion on this
subject, that seems less likely than air pockets which are hard to get out
of the system. This is a real issue, because when the engine is plugs up,
the air collects in the hottest part of the engine, the spark plugs!!

Given these problems, I have considered the plugs up arrangement for the
installations that I have looked at. The reason was that it would be nice to
put the turbo on the bottom for cooling and easy exhaust plumbing. (Turbo
exhaust facing aft in tractor would need a new manifold.) For a pusher the
exhaust faces in the proper direction without any additional bends, tubes
etc. The duct for the inlet air also is pointing in the right direction and
can be short simple and light. The turbo is not in the way of the main
engine mount supports, so that the supports can stay close to the block like
a turbine engine mount. One of the lateral braces does interfere with the
turbo, but is easier to deal with than the main support. There are not as
many convenient places to attach the engine mount to the block. The really
big drawback to this arrangement, is that you need a dry sump oil system to
pull it off. This adds $1500-2000 to the cost of the installation!!!
However, if done properly, and including the other appropriate systems, you
could fly any attitude that suited your mood with this setup.

So tell me what else I am missing guys.

Monty

I am all for the periodic re-confirmation of the laws of physics :-)
Bubbles rise and oil falls.

Paul Lamar
 
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