Better M14P Power Settings

[Ted Waltman]

I flew 2.5 hours at 3,500' today and experimented with various power
settings. I started off by multiplying the listed RPM #'s off of the
Murphy Air page by .67, assuming that folks are right in saying I'm
seeing prop, rather than engine, RPM on my engine monitor.

knot fuel MP RPM Oil EGT CHT OAT
indic Centigrade
97 15.9 24.3 1500 66 863 160 13
90 17.6 28.1 1340 64 833 160 13
95 15.6 25.9 1400 59 854 160 12

Bottom line seems to be that I was previously running to low MP and too
high prop RPM. On the MAM website, the last line in the chart shows
1730 on the RPM, which would equate to 1159 prop rpm (for the Cruise II
setting). I tried pulling the prop rpm below 1400 with even higher MP
than above but the engine just did not sound right at all. Hence, I did
not run at any lower RPM than 1400 for more than perhaps 30 seconds or
so--not long enough for parameters to stabilize where I thought I was
getting a valid measurement.

At takeoff, max rpm seems to be 2130 (quick glance mind you), which is
close to the 1943 one gets when multiplying 2900 by .67.

I still haven't gotten around to quickly undoing the cowl and looking
inside the oil tank after landing to see what if any froth there might
be. I'll try to get to that project in the next few flights.

Ted


-----Original Message-----
From: Ryan Mowat [mailto:RMowat@forge-industrial.com]
Sent: Thu 6/3/2004 2:23 PM
To: 'Scott & Leere' Aldrich'
Cc: Ted Waltman
Subject: RE: M14 Power settings
The RPM is geared to the engine by 0.67 - how are you measuring the rpm
- the mags? If so 2150/.67 = 3208 RPM which would mean your over RPM
the prop - very dangerous.

Consider asking local shop for hand held tach to make sure you do not
exceed rated RPM.

Ryan Mowat, P.Eng.
30528 1A Greatnorthern Ave
Abbotsford, BC V2T 6H4
(604) 556-7222 (ext 307), (604) 556-7215 (Fax)
-----Original Message-----
From: Scott & Leere' Aldrich [mailto:flynski@mwutah.com]
Sent: Thursday, June 03, 2004 9:39 AM
To: Ryan Mowat
Cc: Ted Waltman
Subject: M14 Power settings

Hi Ryan, how's it going?

I am attaching in this email a note from another Moose owner (Ted
Waltman). He didn't build it but just purchased it about a week ago.
It has the same engine as your and the same prop. I (we) are just
curious as to what kind of MP and RPM you are able to get with yours.

It just occurred to me to ask Ted if it is reading prop rpm or engine
rpm??

Thanks,
Scott

I'll forward this to Ryan Mowat and see what he is getting for power
settings. He has the same engine and he also has the same engine
monitor but has it hooked up to all nine.

-----Original Message-----
From: Ted Waltman [mailto:tedwaltman@i1ci.com]
Sent: Thursday, June 03, 2004 9:41 AM
To: Scott & Leere' Aldrich
Cc: rebel-builders@dcsol.com
Subject: engine monitor

It only monitor's one cylinder (I'll have to look to see which one). As
I recall, it was something about Brent commenting about monitoring the
one that typically is the hottest. I agree that a 9-cylinder model is
preferred; I'm going to be looking for such at Oshkosh.

I didn't check the frothing issue at my one intermediate fuel stop, as I
was trying to beat an after-dark arrival in Iowa. I got in just after
the sun set as it was. Had to use my hiking headlamp to see the
switches and such after shutdown.

Here are prelim power #'s (I'll do a lot more experimenting in the
coming days and report more to the list):
Indicated
Altitude Speed (knots) fuel (gph) Manifold RPM
13,500 82 18.2
17.6 1790
13,500 80 15
16 1710
3,500 83 17.1
20.1 1770
3,600 78 15.3
18.9 1770
3,500 85 16.5
20.1 1800
3,500 92 17.9
22.4 1800
3,500 98 18.7
23.9 1810

There's no way I'm seeing any RPM anywhere even remotely close to 2,900.
Highest I've seen so far is something like 2150; I'll have one my
passengers look at the RPM gauge at takeoff power tomorrow and report on
maximum RPM then.

Ted







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