We had an oil system failure this morning running up the TTC engine. A
screw came out of the engine oil pressure pump part of the dry sump
pump. It doesn't take long at 150 psi to piss oil all over the air
plane and the ramp.
One would think paying $50,000 for this engine the screws would have
been safety wired. I bought 2 dozen NAS filister drilled head 10-24
screws from Aircraft Spruce for 27 cents each.
You must look at every detail in your home built aircraft and
consider what would happen if that detail (what ever it may be)
failed. Make a list of every nut and bolt in the entire aircraft.
That is what Van's Aircraft does.
We also cut the air going into the cooling system down to a slot 1.5
inches high by 20 inches wide and the engine temp went all the way up
to 140 F at 8300 RPM. ROFL.
We took the oil cooler off as well and the oil temp went up as well.
We don't need no stinking oil cooler when carrying 4 gallons of Mobil
One.
More on this later today when I get the logged data out of the
Motec.
BTW the gap in the iridium RX8 plugs is .021" inches.
Paul Lamar
Paul, It is acceptable to use automotive parts in an experimental,
but everyone must keep in mind to adapt standard aircraft practice to
those parts...... your screws being a great example! Keep it
safe..... self locking nuts, cotter pins or safety wire......
Larry Childs
Here is the test run screen captures of the data log.
The water temperature increased to 143 F but could go higher with a
longer run and the small rad opening. The oil reached 156.4 F with
no oil cooler. That too could go higher with a longer run at 8000 RPM
and more boost.
Note with the small prop the engine will do 8300 RPM with hardly any
manifold pressure. The manifold pressure never got over 55 inches of
HG at 8300 RPM with the small prop.
Paul Lamar
Paul,
Maybe it's time to have a second critical set of eyes look over the
all the
work that has been done..... something like a mini annual
inspection done by
an IA experienced 4with experimental aircraft.
Barry Bordes
Thats a good idea. IA's are rarely called upon to inspect
experimental's I
suspect :-) $500 for their signature alone :-)
Dry sump pumps are rather rare on aircraft so the screws were
overlooked by
our A&P licensed mechanic.
As far as the fuel injector mounting problem that was a very
unusual and
defective design. An IA would not know how to handle that as EFI
is rare
on certified engines. Maybe on light sport Rotax's.
It would take a mechanical engineer to spot the problem with the
bad design.
The pivot point was not on the center line of the injector
separating force
consequently the 150 psi force disjointed the extender from the
injector.
It was not obvious why it required safety wire to hold it in place
and it
was left off. It stems from the fact that the compact Bosch injectors
are not quasi standard length and extenders were used to make
them longer.
Probably because RB had injector holders for the longer injectors
and did
not want to redesign them for the short Bosch injectors.
We supply p-port mounting blocks for RX8 and Siemens injectors.
As you can tell from the number of pictures I have.... this was
discussed
many times in the past 18 years. If Jim M had read the newsletter
he would
have been aware of some of these things.
Paul Lamar
Here is the dry sump pump safety wired.
Working on this with the engine in the aircraft was a night mare.
It should have been done long before the engine was installed in the
airplane. It took about 16 man hours.
The TTC motor mount is horribly designed and gets in the way no
matter what.
The person that designed it did not have a clue about the rotary.
That person was fired but it was too costly and time consuming to start
over.
There are 17 titanium 1/2 inch bolts holding it together. The
motor mount
attachments at the rear of the engine are totally and completely
unnecessary. Here are several Reno Racer 3D's to show how it is
done with a
turbo.
All you really need are two bi-pods and a lateral brace under or
along side
the engine.
Paul Lamar
Paul,
The good news...... that mount will hold about 4000 HP!
Larry Childs
ROFL Maybe :-) some of the joints are suspect.
Paul Lamar
Just like the A&P licence, the IA certificate is just a card that makes
it legal for someone to sign certain maintenance documents.
Just like A&Ps there are good and bad IAs, there are experienced and
inexperienced IAs, and there are knowledgeable and 'stupid' IAs.
As mentioned before though, the legality of an IAs signature isn't
required for a homebuilt.
However....
Regardless of the legalities, when working on a project like this, it is
critical to have someone that is not 'close' to the project do a good
inspection/review of the work before flying. It doesn't have to be an
A&P or IA, but it does have to be someone that is both experienced and
knowledgeable, as well as or perhaps even more importantly, someone who
possesses common sense wisdom.
When working on a project for days, weeks, months, you are no longer
able to see some of those problems because you are too 'close' to it, it
really takes someone not personaly involved/invested to see some of
those blatantly obvious issues.
narfi
Just like the A&P licence, the IA certificate is just a card that
makes it legal for someone to sign certain maintenance documents.
Just like A&Ps there are good and bad IAs, there are experienced and
inexperienced IAs, and there are knowledgeable and 'stupid' IAs. As
mentioned before though, the legality of an IAs signature isn't
required for a homebuilt.
However.... Regardless of the legalities, when working on a project
like this, it is critical to have someone that is not 'close' to the
project do a good inspection/review of the work before flying. It
doesn't have to be an A&P or IA, but it does have to be someone that
is both experienced and knowledgeable, as well as or perhaps even
more importantly, someone who possesses common sense wisdom.
When working on a project for days, weeks, months, you are no longer
able to see some of those problems because you are too 'close' to it,
it really takes someone not personally involved/invested to see some
of those blatantly obvious issues.
narfi willem
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