Constant speed props

On Fri, 25 Jun 2004 14:09:20 -0400, charles.k.scott wrote:

On Fri, 25 Jun 2004 11:44:30 -0500, Greg Copeland
wrote:

Well, keep in mind that it was the first article of his that I read. It
presumed that I had already been introduced to the LOP concept. I had
not. In fact, for some engines that I used (r/c nitro and car engines),
too lean is a great way to completely destroy an engine.

But Greg, you just described a situation worlds apart from what Deakin
advocates.

I know that. But, when you're ignorant of the details of what he's
prescribing and know only the scary details of your own universe, it's a
natural reaction. I'm not saying it's justified. I'm just saying, that
was my reaction.

Running a race engine, any race engine, at full power and
too lean is not anywhere near the LOP description for aviation
engines. Yup, running an engine like that probably would blow it up.

Yep. That's certainly a good point.


For takeoff, his recommendation is to use FULL RICH. Not only full
rich, he recommends those who are flying behind the large 6 bangers
check out the mixture setup to make sure that it is reaching the
proper full fuel pressure. If it's set a little too low, something
below the specified maximum pressure, *THAT* situation is worrisome
and could cause engine problems. That's because the engine needs to
have the full rich mixture at takeoff power to stay cool. Having the
mixture on the rich side of ideal slows the burning down enough to
keep the Peak Pressure Point at around 16 degrees past top dead
center.

I have read that article since my ignorant gut reaction was made known.
I think he makes a lot of sense! I think he makes a powerful argument. I
think he goes to lengths to describe when, what, why, and how. That's all
excellent. But, if it's my $20k+ engine on the line, that's a long hard
thought before I'd commit to it. After all, he makes it perfectly clear
that you have to have an engine monitor, which makes it a
hole-in-your-wallet type of commitment for many. Not to mention,
irrational whispers in your head can sometimes just be a bitch to get
past, no matter what data is telling you.

Needless to say, I'll certaily be looking more into it. It sounds very
interesting and it does seem to be well reseached, both presently and
historically. Just the same, I'd still like to be more educated on the
topic.


Cheers!

Greg