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1. 11:21 AM - Re: LOP Article (Jef Vervoort)
2. 07:41 PM - Re: LOP Article (Tim Farrell)
Message 1
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Dean,
My prop is an MT 3 blade.
I also should correct myself: I do not have an AFP, but a Precision
Airmotive Silverhawk EX5 VA1.
The roughness in my case is best experienced after start-up when it turns
some 1000-1200 RPM; I try to stabilize the RPM and then lean and see the RPM
rise with some 200 to 250 RPM until I hear the engine is turning smooth and
is at its maximum RPM.
I did not have a real problem in the sense of the engine quit in the 40
hours of flying of the all new RV9A.
I found the reading of the article by Peter Garrison very interesting, and
understandable.
What I also did is reading the complete instructions of Precision Airmotive,
and I realize now that, apart from the installation instructions that I
studied and followed with great care, I did not pay enough attention to the
appendix that explains the Idle Speed and Mixture Adjustments.
I will work on that one as soon as possible.
Thanks for your reply and best wishes,
Jef Vervoort, Antwerp County, Belgium.
---Oorspronkelijk bericht----- or
Van: owner-rv-list-server@matronics.com
[mailto:owner-rv-list-server@matronics.com] Namens DEAN PSIROPOULOS
Verzonden: maandag 29 april 2013 7:21
Aan: rv-list@matronics.com
Onderwerp: RV-List: LOP Article
--> <dean.psiropoulos@verizon.net>
What prop do you have on the engine Jeff? I have an 0-360 with AFP
conversion and I was using a wood prop for first flights. The thing had
trouble with off idle acceleration and idling when hot. After 5 months of
tinkering I finally discovered it was the flow divider. Don fixed it for
free and things worked well for a few months. The airplane ran great, idled
great and then seemed to revert to its prior condition but, after
rechecking, it wasn't the flow divider and I never did figure out what
exactly it was. When I was at 35 hours I installed a Sensenich FP metal
prop which is at least 25 pounds heavier with a lot more inertia than the
wood prop. The engine didn't have any more problems with quitting after
landing because the inertia of the metal prop kept the engine turning
through the roughness that would normally cause the engine to quit with the
lighter wood prop installed. I finally messed with the idle mixture on the
servo enough that the engine would idle smooth without the rough running
cycles but that seemed to be a little too lean for off idle acceleration.
When I would push the throttle in during a recovery from a power off stall
or during touch and gos, the engine would sputter and run rough for the
first 1/4 throttle and then smooth out and run well. It never quit under
these conditions but it did bother me so I decided to richen the idle
mixture a bit to stop that from happening. When I did that, the old rough
running idle cycles reared their ugly head again but, at least no more
sputtering off idle when hot.
These rough running idle cycles occur after the engine has warmed up. When
I start the engine (cold) it idles solidly at Don's suggested RPM (750)
until CHTs get over 150 and the under cowl temps get warm. Then, suddenly
it goes into this mode where the prop will spin several blades at 750 RPM
and then the RPM will drop to apppx 600 for a few blades and then back to
750 RPM and, the cycle repeats itself. I think these RPM drops are caused
by the engine loading up after it is warmed up but I can't be sure. When I
first discovered the flow divider was sticking, it was acting that way but
when Don repaired it, it was rock solid (after a mixture adjustment) at 750
RPM for a couple months, even with low inertia wood prop in the middle of a
hot Florida summer. Then it reverted to its old self and caused some
nuisance engine quitting after landing and taxiing. I checked the flow
divider again but that was not the problem. When I've got the cowl off I
always check the intake tube bolts and hose clamps to make sure they aren't
loose and letting the idle go lean (but if my hypothesis is that the engine
is loading up with excess fuel then an intake leak is not likely to be the
problem so go figure). Bottom line is that if I leave the mixture full rich
while idling and taxiing it is not nearly as big an issue with the metal
prop due to inertia. But when I hear the engine start into the rough idle,
that's my clue to lean the mixture and things smooth right out. I've been
going to fly up to Don's and have him look at it and try adjusting it but
haven't had the time. Leaning at idle works well and I would rather have to
do that than have the engine sputtering during a stall recovery or go
around. Just my observations after flying with the setup for four years.
Regards
Dean Psiropoulos
RV-6A N197DM
Tarpon Sprgs, FL (25 Meters MSL)
________________________________ Original Message
_____________________________________
From: "Jef Vervoort" <jef.vervoortw@telenet.be>
Subject: RE: RV-List: LOP Article - FLYING magazine
RV9A with XIO-320 and Airflow Performance, needs leaning on the ground, near
sea level.
Jef Vervoort, Belgium.
Message 2
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Jef,
Sorry to jump in here, and honetly I haven't had time to read all the
thread, but if you are getting a 200-250 rpm rise when you pull back the
mixture, you are running very very rich. You need to lean the mixture
at the mixture screw. At sea level you should be set up slightly rich
at full mixture, but not that rich. When you pull the throttle back
(very slowly) while at idle (around 800 rpm) you should see a 25-50 rpm
rise, right before the engine cuts out. Once you have the mixture
leaned, then you can set the idle speed. Before that, back the idle
speed screw off and just adjust with the throttle. We do this with two
people, with the engine running. After each adjustment we clear the
engine by running it up to 1500 rpm. Obviously, unless you are around
competent airplane people who are comfortable working around a spinning
propeller, you should probably shutdown between adjustments. One tip,
to set the idle speed after you have everything dialed in, set the rpm
to your desired idle rpm and pull the mixture, but don't touch the
throttle. Then all you have to do is set the idle screw to touch the
idle arm in that position.
Engines are really expensive. I highly suggest paying a professional to
give you a few hours of training on how to set them up, monitor them,
check them, etc. It's money well spent.
All the best.
Tim
On 4/29/2013 11:20 AM, Jef Vervoort wrote:
>
> Dean,
>
> My prop is an MT 3 blade.
> I also should correct myself: I do not have an AFP, but a Precision
> Airmotive Silverhawk EX5 VA1.
> The roughness in my case is best experienced after start-up when it turns
> some 1000-1200 RPM; I try to stabilize the RPM and then lean and see the RPM
> rise with some 200 to 250 RPM until I hear the engine is turning smooth and
> is at its maximum RPM.
> I did not have a real problem in the sense of the engine quit in the 40
> hours of flying of the all new RV9A.
>
> I found the reading of the article by Peter Garrison very interesting, and
> understandable.
> What I also did is reading the complete instructions of Precision Airmotive,
> and I realize now that, apart from the installation instructions that I
> studied and followed with great care, I did not pay enough attention to the
> appendix that explains the Idle Speed and Mixture Adjustments.
> I will work on that one as soon as possible.
>
> Thanks for your reply and best wishes,
>
> Jef Vervoort, Antwerp County, Belgium.
>
> ---Oorspronkelijk bericht----- or
> Van: owner-rv-list-server@matronics.com
> [mailto:owner-rv-list-server@matronics.com] Namens DEAN PSIROPOULOS
> Verzonden: maandag 29 april 2013 7:21
> Aan: rv-list@matronics.com
> Onderwerp: RV-List: LOP Article
>
> --> <dean.psiropoulos@verizon.net>
>
> What prop do you have on the engine Jeff? I have an 0-360 with AFP
> conversion and I was using a wood prop for first flights. The thing had
> trouble with off idle acceleration and idling when hot. After 5 months of
> tinkering I finally discovered it was the flow divider. Don fixed it for
> free and things worked well for a few months. The airplane ran great, idled
> great and then seemed to revert to its prior condition but, after
> rechecking, it wasn't the flow divider and I never did figure out what
> exactly it was. When I was at 35 hours I installed a Sensenich FP metal
> prop which is at least 25 pounds heavier with a lot more inertia than the
> wood prop. The engine didn't have any more problems with quitting after
> landing because the inertia of the metal prop kept the engine turning
> through the roughness that would normally cause the engine to quit with the
> lighter wood prop installed. I finally messed with the idle mixture on the
> servo enough that the engine would idle smooth without the rough running
> cycles but that seemed to be a little too lean for off idle acceleration.
> When I would push the throttle in during a recovery from a power off stall
> or during touch and gos, the engine would sputter and run rough for the
> first 1/4 throttle and then smooth out and run well. It never quit under
> these conditions but it did bother me so I decided to richen the idle
> mixture a bit to stop that from happening. When I did that, the old rough
> running idle cycles reared their ugly head again but, at least no more
> sputtering off idle when hot.
>
>
> These rough running idle cycles occur after the engine has warmed up. When
> I start the engine (cold) it idles solidly at Don's suggested RPM (750)
> until CHTs get over 150 and the under cowl temps get warm. Then, suddenly
> it goes into this mode where the prop will spin several blades at 750 RPM
> and then the RPM will drop to apppx 600 for a few blades and then back to
> 750 RPM and, the cycle repeats itself. I think these RPM drops are caused
> by the engine loading up after it is warmed up but I can't be sure. When I
> first discovered the flow divider was sticking, it was acting that way but
> when Don repaired it, it was rock solid (after a mixture adjustment) at 750
> RPM for a couple months, even with low inertia wood prop in the middle of a
> hot Florida summer. Then it reverted to its old self and caused some
> nuisance engine quitting after landing and taxiing. I checked the flow
> divider again but that was not the problem. When I've got the cowl off I
> always check the intake tube bolts and hose clamps to make sure they aren't
> loose and letting the idle go lean (but if my hypothesis is that the engine
> is loading up with excess fuel then an intake leak is not likely to be the
> problem so go figure). Bottom line is that if I leave the mixture full rich
> while idling and taxiing it is not nearly as big an issue with the metal
> prop due to inertia. But when I hear the engine start into the rough idle,
> that's my clue to lean the mixture and things smooth right out. I've been
> going to fly up to Don's and have him look at it and try adjusting it but
> haven't had the time. Leaning at idle works well and I would rather have to
> do that than have the engine sputtering during a stall recovery or go
> around. Just my observations after flying with the setup for four years.
> Regards
>
> Dean Psiropoulos
> RV-6A N197DM
> Tarpon Sprgs, FL (25 Meters MSL)
>
> ________________________________ Original Message
> _____________________________________
>
> From: "Jef Vervoort" <jef.vervoortw@telenet.be>
> Subject: RE: RV-List: LOP Article - FLYING magazine
>
> RV9A with XIO-320 and Airflow Performance, needs leaning on the ground, near
> sea level.
>
> Jef Vervoort, Belgium.
>
>
>
>
>
--
Tim Farrell -
Aircrafters -
Owner/Manager -
(831) 722-9141 -
www.aircraftersLLC.com
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