September - October - The Recreational Aircraft Association

a year. I borrowed units, which did not work that
great and more often than not, I did not inspect every
filter.
Filter inspection is a cheap and easy way to have
a look and see what is going on in your engine. I did
not feel good about not doing this essential job and as
I did not like the commercial cutters that are available
I decided to see if I could make one to use myself.
Most tools work on a pipe cutter principal with a
little cutting wheel that gets progressively tightened
with each spin around the filter. These work ok but it
takes a bit of time.
To build one I used a slightly different approach;
I use lever action rather than a thumb screw to apply
pressure to the cutting wheel. What I discovered
was, that with this method the cutting wheel breaks
through the metal within about an inch of movement
and then once around the filter cuts the top off
cleanly.
The tool worked so well I showed it to a number
of mechanic friends who were very impressed with
how easy the cutter worked. With this encouragement
I had a computer model drawn up and parts laser cut
Push or Pull?
Eustace Bowhay on
Fuel Injection vs. Carbuettors
I’d like to pass on my experience with fuel systems
over the years and as related to my RV-6.
All of my flying with horizontally opposed
engines since the sixties had been with fuel injection
until my RV-6. At the time of building the -6 I didn’t
think I had a choice, with Van recommending only
the 0-320 and 0-360 Lycomings.
My choice was the 0-360. With most of our flying
here over hostile terrain and sparsely settled areas,
I decided to install the Gem graphic display. This
would give me advance warning of any valve problems,
as well as mixture and ignition info. This is
when the wide spread in mixture to the four cylinders
showed up, and having to lean to the leanest
cylinder wasn’t really the most efficient.
Carb icing was a bit of a concern, with the difficulty
of getting what I felt was adequate hot air
for carb heat. Turned out to be a non-issue, with the
crossover exhaust system located over the alternate
air door.
and heat treated so that I could offer this simple tool
to other aircraft owners at a economical price of $53.
Cleveland Tools will be retailing this tool as well as
myself.
Almost all Lycoming filters have an insert that
protrudes from the filter and my Tool spins around
this threaded insert. For those filters that do not have
inserts, such as most Continental and Rotax filters, I
include a threaded bolt that will provide this pivot
point. I have also incorporated a second lever hole so
that the Tool can be used to cut open the small filters
that fit the popular 912 Rotax series of engines.
I also provide instruction pages that describe not
only how to cut open a filter but also how to actually
inspect a filter. The whole process takes about fifteen
minutes and should be done each and every time you
remove a filter.
For further information contact
Tom Martin 519-631-1369
email: fairlea@amtelecom.net
On the web: www.cleavelandtoolstore.com
Technical Stuff
I had my engine overhauled in 1996, and decided
to give the Bendix Fuel Injection a try- a system I
was familiar with. This is a big change, requiring
a change in both the engine driven pump. and the
boost pump, because of the higher pressure and the
extra plumbing required. This was another reason
for moving the gascolator into the wing root (so that
the gascolator would not be pressurized). I mounted
the Weldon pump on the fuselage side of the firewall
above the rudder pedals. That wasn’t ideal, because
of the lift, but didn’t want it in the engine compartment
because of the heat and starting problems
associated with fuel injection on short turnarounds.
This problem was completely solved with the installation
of an AirFlow Performance purge valve this
year.
Flying with the fuel injection system is a real
treat, to see the EGTs straight across, and the CHTs
almost the same. The leaning is now the same on all
four cylinders. Carb ice is a thing of the past.
So which system is the best? Here again I think
it is a matter of personal choice. Cost is certainly a
major factor with fuel injection. I believe fuel injection
is more reliable but can honestly say I haven’t
September - October 2007 Recreational Flyer 33