Ernest Christley wrote:

wrote:

I'm getting set to do the ground runs on my engine and intend to run
it throughout the summer at high power settings. I don't understand
people who just bolt an engine, any engine, to the airframe and then
try to go flying without any test runs.

Corky Scott

And don't just run it on the ground. You've got to instrument that
baby. Get a bunch of temperature probes and stick one to everything you
can. Add a handful of accelerometers to measure vibration at multiple
points if you can get your hands on them. I've read that the biggest
advances in aviation power during the second world war came about due to
improvements in instrumentation. It makes sense. You won't know what
to strengthen or cool if you don't know what's hot or under harmonic
vibrations.

Someone here mentioned an adjustable strobe light at night to look for
harmonics.

--
http://www.ernest.isa-geek.org/
"Ignorance is mankinds normal state,
alleviated by information and experience."
Veeduber


Good point. Excellent point, in fact.

My engine is a VW. Not a certified aircraft engine.

Quite a bit less then $1,000,000 has been spent on detailed engineering,
testing, analysis, etc to convert this into a safe aircraft engine.

Even though haven't spent much of that million on engineering, I don't
seem to have much left for instrumentation I suspect the coffee
fund).

Accelerometers struck out - cost, complexity, and I wouldn't know what
to do with them anyway.


One thing I would like to instrument is the carburetor temperature.

Not a permenant gauge on the panel (I have one - but there's no space).
Just a low buck way of monitoring the carb temp in flight for a while to
see whazzappenin and see if pulling the carb heat knob is really doing
anything.


The carb is below the engine (KR2 style intakes manifold from GPAS)
where it is not warmed much from engine heat.

One of these days I want to make new exhaust pipes with a proper
carb heat muff.

But for now, I wonder if the air passing thru the cylinder fins would
be hot enough (too hot enough?) to work well - or not?

Only way to know for sure is to measure it.

Isn't there supposed to be a way to do that with a digital multimeter
and thermosistor, or thermocouple (what)?

Richard


PS: thanks for remembering the harmonics thread, Robert. (:it was fun

I remember thinking(back then) that I wanted to take a real good look
a the engine installation on the new plane for harmonic reactions.

I even asked around and found someone who have an old variable speed
disco strobe for the job.

But the engine wasn't ready to run back then, and I forgot about it.
Until now.

Thanks.

Richard