Mailing List flyrotary@lancaironline.net Message #43341
From: David Leonard <wdleonard@gmail.com>
Subject: Re: [FlyRotary] Re: Running lean of peak
Date: Thu, 26 Jun 2008 20:07:34 -0700
To: Rotary motors in aircraft <flyrotary@lancaironline.net>
Hi Al,

I would confirm your experience.  It will continue to run 200 LOP, but even at 100 LOP it is starting to have significant misses.  Even 50-60 LOP  has a much rougher feel than ROP, but the EGT's really start to fall off and fuel consumption drops.

I have noticed that much of the problem is rotor balance.  If one rotor is 20 ROP, the other may be well LOP.  If I carefully work to match the rotors then I run much smoother well LOP.  The problem for me is that my rotor balance is very dependent on RPM.  If I get them matched at 5000 RPM, then they are WAY different at 6000 RPM and vise versa. (evidence of a very poor manifold design?!)

For my next turbo destruction cycle, I plan to really focus on EGT (like cert engine pilots have to).  I will balance the rotors at a particular RPM and only run LOP at that RPM.  Otherwise, I will run ROP.  If I can get the turbo to 500 hrs,  that would be less than $2/hr and it would be worth it.  Keep 2 turbos in cycle to the rebuild shop, and always the means to fly around n.a.....  I'll let you know how it goes  :-)

Dave Leonard

On Thu, Jun 26, 2008 at 7:25 PM, Al Gietzen <ALVentures@cox.net> wrote:

 

Al,

 How many hours are on your sparkplugs and are you useing auto fuel or 100LL.........Something to

consider before a 2000 mile trip.........Could be possible indication before the dreaded "SAG"..........

 

I don't recall (have to check the engine log), but I'd guess maybe 20 hrs; only 10 ga 100LL; all the rest unleaded mogas.  I took a leading and trailing out yesterday to look at them and they look fine.

 

Al

 

-------------- Original message from "Al Gietzen" <ALVentures@cox.net>: --------------

I'm finding that at about 100F LOP I sense that the engine is starting to not like it – like it doesn't seem to be entirely smooth; maybe an occasional miss here and there.  Am I right that some of you guys run as much as 200 LOP; or is it my imagination – in both cases.

 

Would timing setting have much of anything to do with running LOP?

 

Just past by the 100 hr mark on the engine near the end of a 500 mile trip on Monday.  I plan to leave next Monday on a round trip of over 2000 nm over the following week.  That'll rack up a few hours.

 

Al




--
David Leonard

Turbo Rotary RV-6 N4VY
http://N4VY.RotaryRoster.net
http://RotaryRoster.net
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