Mintor

[AcrophobicFlyer]

Actually it's called "wake turbulance".  It's when the advancing blade is
passing through dirty turbulant air left from the previous blade.  The most
efficient prop only has one blade and a counter weight for balance.

Regards,
Adam Quennoz
AMA 383866
IMAC 2439
NSRCA 3546

----- Original Message -----
From: "David Lockhart" <DaveL322 at comcast.net>
To: <discussion at nsrca.org>
Sent: Tuesday, May 13, 2003 7:22 PM
Subject: Re: Mintor


> Given all other parameters are similar (airfoil, aspect ratios, etc),
> the 3 blade is never more efficient than an equivalent 2 blade.  More
> little wings are not as efficient as fewer big wings.  I'm sure one of
> the regular contributors to this list could provide more details in
> better form than I.
>
> So far as the 18-10 - a 170 isn't needed.  Any of the current 140s on a
> pipe should turn the APC 18-10 at 8000 - give or take.
>
> For the 3 blader - I've been running an APC 15.75-13 depitched to 11.25
> for about a year now (some may remember seeing it on my plane at the
> 2002 NATs, but you probably didn't hear it!! <G>).  RPM on the ground
> is typically 7,700 (slightly rich)- OS140 EFI, Asano pipe and header,
> 20% S+W fuel.  An APC 18-10 turns about 300 more (slightly rich) and is
> definitely louder - but still quiet compared to many of the setups
> currently used.
>
> I don't remember the exact numbers, but I think the stock 15.75-13 was
> about 500-600 RPM more load (than the 15.75-11).
>
> Regards,
>
> Dave Lockhart
>
> ----- Original Message -----
> From: wgalligan <wgalligan at cnbcom.net>
> Date: Tuesday, May 13, 2003 4:43 pm
> Subject: Re: Mintor
>
> > On the prop thing on the 3M 1.70. Bigger engines dont like to spin
> > as fast and usually are designed to develop more torque in a
> > certian range.  SO if this is true wouldnt you want to prop this
> > engine to be more usefull in the 4000-7800 rpm range?  I'm sure
> > this engine will be capable of turning an 18x10 prop but then the
> > tip speed will go sonic.  What 3 bladers out there do you
> > experienced guys think would work best in loading the engine and
> > giving the best performance?  How does one determine dia. and
> > pitch to load this size of engine? I think taking advantage of
> > this engines midrange transition and torque will be key in making
> > it perform.  Much like the 4c guys enjoy now.
> >
> > While on the subject of 3 blade props...  where does the efficency
> > of a 3 blade come in (rpm) or drop off?
> >
> > Cant wait to get mine bench run and flying.
> > Wayne
> >
> > > Hi Ihncheol,
> > >
> > > The rpms/props may look similar, but the 170 was noticeably more
> > powerful in
> > > the air.  The 140 runs VERY smooth and has good power.  The 170
> > shakes a
> > > little more at idle, but has more power.  With a 20 oz tank I
> > can fly 2
> > > masters patterns and a little more (170).  The engine will give
> > a burp when
> > > the tank is about out.  The 8100 rpm for the 170 might not make
> > it the rpm
> > > king on the ground, but it seemed very powerful in the air.
> > >
> > >
> > >
> > > As for how rich the engines are running?  I don't know.  I use the
> > > "pinch-the-fuel-line" technique for finding the peak, then I
> > back it off a
> > > few clicks, then I fly it.  If it sags on uplines, I land and
> > richen it 1
> > > click and try again.  After doing using method, the ground
> > running was in
> > > the 8100 range.  I would not characterize them as running rich.
> > If they
> > > are, the twin plugs is helping to hide the signs of it which
> > would usually
> > > show up in transition.  I played around with it this weekend and
> > went from a
> > > "rich" midrange to what I thought was about right.  If it gives
> > a loud pop
> > > with pushing from inverted flight while adding power, the
> > midrange is too
> > > lean.
> > >
> > >
> > >
> > > Jim
> > >
> > >
> > >
> > > -----Original Message-----
> > > From: Ihncheol Park [PatternFlyer at msn.com]
> > > Sent: Monday, May 12, 2003 9:15 AM
> > > To: discussion at nsrca.org
> > > Subject: RE: MINTOR
> > >
> > >
> > >
> > > Jim,
> > >
> > > I have a few questions,
> > >
> > > 140 turns APC 16.5 x 12W @ 8350
> > >
> > > 170 turns APC 17 x 12 @ 8100
> > >
> > > both with 15% Cool power?
> > >
> > >
> > >
> > > How rich are the engines running?
> > >
> > > I am not sure how the two props are loading when use on a same
> > engine, but
> > > the output figures sound like 140 is running better.
> > >
> > >
> > >
> > > How about fuel consumption of both engines?
> > >
> > >
> > >
> > > Thanks,
> > >
> > >
> > >
> > > Ihncheol Park
> > >
> > >
> > >
> > >
> > >
> > >
> > >
> > >
> >
> > =====================================
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> > # discussion-request at nsrca.org
> > # and put leave discussion on the first line of the body.
> > #
> >
> >
>
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