Today's Message Index:
----------------------
1. 06:08 AM - Re: OV Protection and AEC 9004-1 module (merlewagner2)
2. 09:02 AM - Re: Lycoming Knock Sensor ()
3. 09:40 AM - Re: Lycoming Knock Sensor (chris)
4. 10:47 AM - Re: Lycoming Knock Sensor (skywagon185guy)
5. 12:43 PM - Re: Lycoming Knock Sensor ()
6. 03:39 PM - Re: Lycoming Knock Sensor (chris)
7. 04:08 PM - Re: Lycoming Knock Sensor (Deems Herring)
Message 1
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| Subject: | Re: OV Protection and AEC 9004-1 module |
Thanks for the info Bob. Any idea if you will come out with the 9004 module in
the future? I will go with the warning lite and B&C OV module for now.
Regarding the Grumman - can't remember that one. I have trouble remembering my
name occasionally.. Serious case of CRS.
Merle
--------
KC1DNJ
General Radiotelephone
Commercial SEL
A&P
Building scale P51, rebuilding Tailwind W10
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=483536#483536
Message 2
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| Subject: | Lycoming Knock Sensor |
Gentlemen,
Thank you for your reply and sorry for the delay in my reply as I was flying
all day yesterday.
Firstly...THANK YOU for your assistance on this...GREATLY APPRECIATED!!!
I have a Lycoming TIO-540 and I run LOP with balanced injectors.
I understand the concept of one sensor per cylinder and I also understand
that the cylinders on the air-cooled aircraft engine is not as tightly
connected to the engine block as a water cooled engine however sound travels
through metal quite quickly and I would think that the sound would move from
each cylinder head to the block.
Would not one sensor mounted on the crankcase "hear" the pings?
I can see if I only installed one sensor on the head of cylinder #1 and a
pinging in cylinder #6 would have a long way to travel and the sound would
distort so the sensor would be unreliable for any cylinder other than its
installed #1 position.
The Knocksense unit that Bob posted is precisely the one that I was looking
at. I was thinking of buying two units and install them at the top of the
engine with one closer to the front and the second closer to the back. On
the Lyco-Saurus the bottom of the engine has the intake and oil pan so I
imagine the liquid and distance from the source of the sound would dampen
out the sound. When you order them they ask you for your cylinder diameter
so they can tune the sensor to your engine.
The next question is.how do you test to see if the darn thing is working?
.
Thanks,
Bill Hunter
From: owner-aeroelectric-list-server@matronics.com
<owner-aeroelectric-list-server@matronics.com> On Behalf Of Robert L.
Nuckolls, III
Sent: Monday, October 1, 2018 10:23 AM
Subject: Re: AeroElectric-List: Lycoming Knock Sensor
At 11:51 PM 9/30/2018, you wrote:
I have never heard of a knock sensor on a Lycoming, even one with electronic
mags. I don't see why you couldn't install one in any of the 1/8 NPT primer
ports though.
Knock sensors are specialized microphones
mounted to some sturdy feature of the
crankcase. The device is optimized to
detect 'knock tones' in the 4-6 Khz range
(determined by cylinder bore diameter).
There are no plug-n-play sensors . . . i.e.
devices that will light a bulb when knocking
is detected. They all require some degree
of signal conditioning to separate noises
of interest from the rest. Here's on example
of a product paired with a sensor that
will illuminate an annunciator when knocking
is detected.
https://tinyurl.com/y79tde7s
There is a constellation of Arduino based
sensor detection projects including sample
software
https://tinyurl.com/hsq4mee
This brings to mind another knowledge nugget
I was offered at a Burlington CO fly-in about
15 years ago. The legacy oxygen sensors used
on automobiles have been demonstrated to function
as advertised in 100LL engines. Met a fellow
with an O2 sensor paired with a millivoltmeter
on the panel. He asserted that the sensor had
several hundred hours on it and had not succumbed
to the predicted 'lead fouling' that discouraged
use on aircraft engines.
One might consider an automotive O2 sensor as
an adjunct for achieving consistent mixture
settings. Here's a short article on how they
work:
https://tinyurl.com/ybm74fvh
Bob . . .
Message 3
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| Subject: | Re: Lycoming Knock Sensor |
Look up efi101.com. This web site has multiple posts on knock or
detonation. Will have to do a search to find posts on knock. A very
good site. csmale@bak.rr.com
On 10/02/2018 09:01 AM, billhuntersemail@gmail.com wrote:
>
> Gentlemen,
>
> Thank you for your reply and sorry for the delay in my reply as I was
> flying all day yesterday.
>
> Firstly...THANK YOU for your assistance on this...GREATLY APPRECIATED!!!
>
> I have a Lycoming TIO-540 and I run LOP with balanced injectors.
>
> I understand the concept of one sensor per cylinder and I also
> understand that the cylinders on the air-cooled aircraft engine is not
> as tightly connected to the engine block as a water cooled engine
> however sound travels through metal quite quickly and I would think
> that the sound would move from each cylinder head to the block.
>
> Would not one sensor mounted on the crankcase hear the pings?
>
> I can see if I only installed one sensor on the head of cylinder #1
> and a pinging in cylinder #6 would have a long way to travel and the
> sound would distort so the sensor would be unreliable for any cylinder
> other than its installed #1 position.
>
> The Knocksense unit that Bob posted is precisely the one that I was
> looking at. I was thinking of buying two units and install them at
> the top of the engine with one closer to the front and the second
> closer to the back. On the Lyco-Saurus the bottom of the engine has
> the intake and oil pan so I imagine the liquid and distance from the
> source of the sound would dampen out the sound. When you order them
> they ask you for your cylinder diameter so they can tune the sensor to
> your engine.
>
> The next question ishow do you test to see if the darn thing is working?
>
>
>
> Thanks,
>
> Bill Hunter
>
> *From:* owner-aeroelectric-list-server@matronics.com
> <owner-aeroelectric-list-server@matronics.com> *On Behalf Of *Robert
> L. Nuckolls, III
> *Sent:* Monday, October 1, 2018 10:23 AM
> *To:* aeroelectric-list@matronics.com
> *Subject:* Re: AeroElectric-List: Lycoming Knock Sensor
>
> At 11:51 PM 9/30/2018, you wrote:
>
> I have never heard of a knock sensor on a Lycoming, even one with
> electronic mags. I don't see why you couldn't install one in any
> of the 1/8 NPT primer ports though.
>
>
> Knock sensors are specialized microphones
> mounted to some sturdy feature of the
> crankcase. The device is optimized to
> detect 'knock tones' in the 4-6 Khz range
> (determined by cylinder bore diameter).
>
> There are no plug-n-play sensors . . . i.e.
> devices that will light a bulb when knocking
> is detected. They all require some degree
> of signal conditioning to separate noises
> of interest from the rest. Here's on example
> of a product paired with a sensor that
> will illuminate an annunciator when knocking
> is detected.
>
> https://tinyurl.com/y79tde7s
>
> There is a constellation of Arduino based
> sensor detection projects including sample
> software
>
> https://tinyurl.com/hsq4mee
>
> This brings to mind another knowledge nugget
> I was offered at a Burlington CO fly-in about
> 15 years ago. The legacy oxygen sensors used
> on automobiles have been demonstrated to function
> as advertised in 100LL engines. Met a fellow
> with an O2 sensor paired with a millivoltmeter
> on the panel. He asserted that the sensor had
> several hundred hours on it and had not succumbed
> to the predicted 'lead fouling' that discouraged
> use on aircraft engines.
>
> One might consider an automotive O2 sensor as
> an adjunct for achieving consistent mixture
> settings. Here's a short article on how they
> work:
>
> https://tinyurl.com/ybm74fvh
>
>
> Bob . . .
>
Message 4
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| Subject: | Re: Lycoming Knock Sensor |
. . .wouldn't you want to mount the sensors such that their sense axis is
in the same plane as the knock vibration; namely line up with the piston
rods and not on top pf the engine case...?
On Tue, Oct 2, 2018 at 9:09 AM <billhuntersemail@gmail.com> wrote:
> Gentlemen,
>
>
> Thank you for your reply and sorry for the delay in my reply as I was
> flying all day yesterday.
>
>
> Firstly...THANK YOU for your assistance on this...GREATLY APPRECIATED!!!
>
>
> I have a Lycoming TIO-540 and I run LOP with balanced injectors.
>
>
> I understand the concept of one sensor per cylinder and I also understand
> that the cylinders on the air-cooled aircraft engine is not as tightly
> connected to the engine block as a water cooled engine however sound
> travels through metal quite quickly and I would think that the sound woul
d
> move from each cylinder head to the block.
>
>
> Would not one sensor mounted on the crankcase =9Chear=9D the
pings?
>
>
> I can see if I only installed one sensor on the head of cylinder #1 and a
> pinging in cylinder #6 would have a long way to travel and the sound woul
d
> distort so the sensor would be unreliable for any cylinder other than its
> installed #1 position.
>
>
> The Knocksense unit that Bob posted is precisely the one that I was
> looking at. I was thinking of buying two units and install them at the t
op
> of the engine with one closer to the front and the second closer to the
> back. On the Lyco-Saurus the bottom of the engine has the intake and oil
> pan so I imagine the liquid and distance from the source of the sound wou
ld
> dampen out the sound. When you order them they ask you for your cylinder
> diameter so they can tune the sensor to your engine.
>
>
> The next question ishow do you test to see if the darn thing is
working?
>
>
>
> Thanks,
>
> Bill Hunter
>
>
> *From:* owner-aeroelectric-list-server@matronics.com <
> owner-aeroelectric-list-server@matronics.com> *On Behalf Of *Robert L.
> Nuckolls, III
> *Sent:* Monday, October 1, 2018 10:23 AM
> *To:* aeroelectric-list@matronics.com
> *Subject:* Re: AeroElectric-List: Lycoming Knock Sensor
>
>
> At 11:51 PM 9/30/2018, you wrote:
>
> I have never heard of a knock sensor on a Lycoming, even one with
> electronic mags. I don't see why you couldn't install one in any of the 1
/8
> NPT primer ports though.
>
>
> Knock sensors are specialized microphones
> mounted to some sturdy feature of the
> crankcase. The device is optimized to
> detect 'knock tones' in the 4-6 Khz range
> (determined by cylinder bore diameter).
>
> There are no plug-n-play sensors . . . i.e.
> devices that will light a bulb when knocking
> is detected. They all require some degree
> of signal conditioning to separate noises
> of interest from the rest. Here's on example
> of a product paired with a sensor that
> will illuminate an annunciator when knocking
> is detected.
>
> https://tinyurl.com/y79tde7s
>
> There is a constellation of Arduino based
> sensor detection projects including sample
> software
>
> https://tinyurl.com/hsq4mee
>
> This brings to mind another knowledge nugget
> I was offered at a Burlington CO fly-in about
> 15 years ago. The legacy oxygen sensors used
> on automobiles have been demonstrated to function
> as advertised in 100LL engines. Met a fellow
> with an O2 sensor paired with a millivoltmeter
> on the panel. He asserted that the sensor had
> several hundred hours on it and had not succumbed
> to the predicted 'lead fouling' that discouraged
> use on aircraft engines.
>
> One might consider an automotive O2 sensor as
> an adjunct for achieving consistent mixture
> settings. Here's a short article on how they
> work:
>
> https://tinyurl.com/ybm74fvh
>
>
> Bob . . .
>
Message 5
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| Subject: | Lycoming Knock Sensor |
>. . .wouldn't you want to mount the sensors such that their sense axis
is in the same plane as the knock vibration; namely line up with the
piston rods and not on top pf the engine case...?
I was kinda wondering the same thing.
If I had the money I would buy six knock detection systems and have one
sensor per cylinderand if I did the questions would be:
-Should one knock sensor be installed on the sidewall of each cylinder?
-Or should one knock sensor be installed at the top of the cylinder head
near the rocker cover?
I am realistically only going to install one or two knock sensors so
does the ping sound get transmitted through the metal of the engine to
be heard practically everywhere? If so then I imagine only one sensor
installed on the crankcase split somewhere in the middle would be
sufficient. Yes if you only have one sensor then you really do not know
what cylinder is pinging however for my purposes I simply want to halt
detonation ASAP and I do not really know care what cylinder.
Thanks,
Bill Hunter
From: owner-aeroelectric-list-server@matronics.com
<owner-aeroelectric-list-server@matronics.com> On Behalf Of
skywagon185guy
Sent: Tuesday, October 2, 2018 10:47 AM
Subject: Re: AeroElectric-List: Lycoming Knock Sensor
. . .wouldn't you want to mount the sensors such that their sense axis
is in the same plane as the knock vibration; namely line up with the
piston rods and not on top pf the engine case...?
On Tue, Oct 2, 2018 at 9:09 AM <billhuntersemail@gmail.com
<mailto:billhuntersemail@gmail.com> > wrote:
Gentlemen,
Thank you for your reply and sorry for the delay in my reply as I was
flying all day yesterday.
Firstly...THANK YOU for your assistance on this...GREATLY APPRECIATED!!!
I have a Lycoming TIO-540 and I run LOP with balanced injectors.
I understand the concept of one sensor per cylinder and I also
understand that the cylinders on the air-cooled aircraft engine is not
as tightly connected to the engine block as a water cooled engine
however sound travels through metal quite quickly and I would think that
the sound would move from each cylinder head to the block.
Would not one sensor mounted on the crankcase =9Chear=9D the
pings?
I can see if I only installed one sensor on the head of cylinder #1 and
a pinging in cylinder #6 would have a long way to travel and the sound
would distort so the sensor would be unreliable for any cylinder other
than its installed #1 position.
The Knocksense unit that Bob posted is precisely the one that I was
looking at. I was thinking of buying two units and install them at the
top of the engine with one closer to the front and the second closer to
the back. On the Lyco-Saurus the bottom of the engine has the intake
and oil pan so I imagine the liquid and distance from the source of the
sound would dampen out the sound. When you order them they ask you for
your cylinder diameter so they can tune the sensor to your engine.
The next question ishow do you test to see if the darn thing is
working?
Thanks,
Bill Hunter
From: owner-aeroelectric-list-server@matronics.com
<mailto:owner-aeroelectric-list-server@matronics.com>
<owner-aeroelectric-list-server@matronics.com
<mailto:owner-aeroelectric-list-server@matronics.com> > On Behalf Of
Robert L. Nuckolls, III
Sent: Monday, October 1, 2018 10:23 AM
<mailto:aeroelectric-list@matronics.com>
Subject: Re: AeroElectric-List: Lycoming Knock Sensor
At 11:51 PM 9/30/2018, you wrote:
I have never heard of a knock sensor on a Lycoming, even one with
electronic mags. I don't see why you couldn't install one in any of the
1/8 NPT primer ports though.
Knock sensors are specialized microphones
mounted to some sturdy feature of the
crankcase. The device is optimized to
detect 'knock tones' in the 4-6 Khz range
(determined by cylinder bore diameter).
There are no plug-n-play sensors . . . i.e.
devices that will light a bulb when knocking
is detected. They all require some degree
of signal conditioning to separate noises
of interest from the rest. Here's on example
of a product paired with a sensor that
will illuminate an annunciator when knocking
is detected.
https://tinyurl.com/y79tde7s
There is a constellation of Arduino based
sensor detection projects including sample
software
https://tinyurl.com/hsq4mee
This brings to mind another knowledge nugget
I was offered at a Burlington CO fly-in about
15 years ago. The legacy oxygen sensors used
on automobiles have been demonstrated to function
as advertised in 100LL engines. Met a fellow
with an O2 sensor paired with a millivoltmeter
on the panel. He asserted that the sensor had
several hundred hours on it and had not succumbed
to the predicted 'lead fouling' that discouraged
use on aircraft engines.
One might consider an automotive O2 sensor as
an adjunct for achieving consistent mixture
settings. Here's a short article on how they
work:
https://tinyurl.com/ybm74fvh
Bob . . .
Message 6
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|
| Subject: | Re: Lycoming Knock Sensor |
knock sensing is quite complex. Search efi101.com forums for posts on
knock sensing. It will give you and idea of how to go about doing your
proposal. csmale@bak.rr.com
On 10/02/2018 12:42 PM, billhuntersemail@gmail.com wrote:
>
> >. . .wouldn't you want to mount the sensors such that their sense
> axis is in the same plane as the knock vibration; namely line up with
> the piston rods and not on top pf the engine case...?
>
> I was kinda wondering the same thing.
>
> If I had the money I would buy six knock detection systems and have
> one sensor per cylinderand if I did the questions would be:
>
> -Should one knock sensor be installed on the sidewall of each cylinder?
>
> -Or should one knock sensor be installed at the top of the cylinder
> head near the rocker cover?
>
> I am realistically only going to install one or two knock sensors so
> does the ping sound get transmitted through the metal of the engine to
> be heard practically everywhere? If so then I imagine only one sensor
> installed on the crankcase split somewhere in the middle would be
> sufficient. Yes if you only have one sensor then you really do not
> know what cylinder is pinging however for my purposes I simply want to
> halt detonation ASAP and I do not really know care what cylinder.
>
>
>
> Thanks,
>
> Bill Hunter
>
> *From:* owner-aeroelectric-list-server@matronics.com
> <owner-aeroelectric-list-server@matronics.com> *On Behalf Of
> *skywagon185guy
> *Sent:* Tuesday, October 2, 2018 10:47 AM
> *To:* aeroelectric list <aeroelectric-list@matronics.com>
> *Subject:* Re: AeroElectric-List: Lycoming Knock Sensor
>
> . . .wouldn't you want to mount the sensors such that their sense axis
> is in the same plane as the knock vibration; namely line up with the
> piston rods and not on top pf the engine case...?
>
> On Tue, Oct 2, 2018 at 9:09 AM <billhuntersemail@gmail.com
> <mailto:billhuntersemail@gmail.com>> wrote:
>
> Gentlemen,
>
> Thank you for your reply and sorry for the delay in my reply as I
> was flying all day yesterday.
>
> Firstly...THANK YOU for your assistance on this...GREATLY
> APPRECIATED!!!
>
> I have a Lycoming TIO-540 and I run LOP with balanced injectors.
>
> I understand the concept of one sensor per cylinder and I also
> understand that the cylinders on the air-cooled aircraft engine is
> not as tightly connected to the engine block as a water cooled
> engine however sound travels through metal quite quickly and I
> would think that the sound would move from each cylinder head to
> the block.
>
> Would not one sensor mounted on the crankcase hear the pings?
>
> I can see if I only installed one sensor on the head of cylinder
> #1 and a pinging in cylinder #6 would have a long way to travel
> and the sound would distort so the sensor would be unreliable for
> any cylinder other than its installed #1 position.
>
> The Knocksense unit that Bob posted is precisely the one that I
> was looking at. I was thinking of buying two units and install
> them at the top of the engine with one closer to the front and the
> second closer to the back. On the Lyco-Saurus the bottom of the
> engine has the intake and oil pan so I imagine the liquid and
> distance from the source of the sound would dampen out the sound.
> When you order them they ask you for your cylinder diameter so
> they can tune the sensor to your engine.
>
> The next question ishow do you test to see if the darn thing is
> working?
>
>
>
> Thanks,
>
> Bill Hunter
>
> *From:* owner-aeroelectric-list-server@matronics.com
> <mailto:owner-aeroelectric-list-server@matronics.com>
> <owner-aeroelectric-list-server@matronics.com
> <mailto:owner-aeroelectric-list-server@matronics.com>> *On Behalf
> Of *Robert L. Nuckolls, III
> *Sent:* Monday, October 1, 2018 10:23 AM
> *To:* aeroelectric-list@matronics.com
> <mailto:aeroelectric-list@matronics.com>
> *Subject:* Re: AeroElectric-List: Lycoming Knock Sensor
>
> At 11:51 PM 9/30/2018, you wrote:
>
> I have never heard of a knock sensor on a Lycoming, even one
> with electronic mags. I don't see why you couldn't install one
> in any of the 1/8 NPT primer ports though.
>
>
> Knock sensors are specialized microphones
> mounted to some sturdy feature of the
> crankcase. The device is optimized to
> detect 'knock tones' in the 4-6 Khz range
> (determined by cylinder bore diameter).
>
> There are no plug-n-play sensors . . . i.e.
> devices that will light a bulb when knocking
> is detected. They all require some degree
> of signal conditioning to separate noises
> of interest from the rest. Here's on example
> of a product paired with a sensor that
> will illuminate an annunciator when knocking
> is detected.
>
> https://tinyurl.com/y79tde7s
>
> There is a constellation of Arduino based
> sensor detection projects including sample
> software
>
> https://tinyurl.com/hsq4mee
>
> This brings to mind another knowledge nugget
> I was offered at a Burlington CO fly-in about
> 15 years ago. The legacy oxygen sensors used
> on automobiles have been demonstrated to function
> as advertised in 100LL engines. Met a fellow
> with an O2 sensor paired with a millivoltmeter
> on the panel. He asserted that the sensor had
> several hundred hours on it and had not succumbed
> to the predicted 'lead fouling' that discouraged
> use on aircraft engines.
>
> One might consider an automotive O2 sensor as
> an adjunct for achieving consistent mixture
> settings. Here's a short article on how they
> work:
>
> https://tinyurl.com/ybm74fvh
>
>
> Bob . . .
>
Message 7
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| Subject: | Re: Lycoming Knock Sensor |
Here is a link to a paper about setting up knock sensing with a link to an IC used
for processing.
http://www.ti.com/lit/an/slyt580/slyt580.pdf
Deems Herring
________________________________________
From: owner-aeroelectric-list-server@matronics.com <owner-aeroelectric-list-server@matronics.com>
on behalf of chris <csmale@bak.rr.com>
Sent: Tuesday, October 2, 2018 6:37 PM
Subject: Re: AeroElectric-List: Lycoming Knock Sensor
knock sensing is quite complex. Search efi101.com forums for posts on knock sensing. It will give you and idea of how to go about doing your proposal. csmale@bak.rr.com<mailto:csmale@bak.rr.com>
On 10/02/2018 12:42 PM, billhuntersemail@gmail.com<mailto:billhuntersemail@gmail.com> wrote:
>. . .wouldn't you want to mount the sensors such that their sense axis is in the
same plane as the knock vibration; namely line up with the piston rods and
not on top pf the engine case...?
I was kinda wondering the same thing.
If I had the money I would buy six knock detection systems and have one sensor
per cylinderand if I did the questions would be:
-Should one knock sensor be installed on the sidewall of each cylinder?
-Or should one knock sensor be installed at the top of the cylinder head near the
rocker cover?
I am realistically only going to install one or two knock sensors so does the ping
sound get transmitted through the metal of the engine to be heard practically
everywhere? If so then I imagine only one sensor installed on the crankcase
split somewhere in the middle would be sufficient. Yes if you only have one
sensor then you really do not know what cylinder is pinging however for my purposes
I simply want to halt detonation ASAP and I do not really know care what
cylinder.
Thanks,
Bill Hunter
From: owner-aeroelectric-list-server@matronics.com<mailto:owner-aeroelectric-list-server@matronics.com> <owner-aeroelectric-list-server@matronics.com><mailto:owner-aeroelectric-list-server@matronics.com> On Behalf Of skywagon185guy
Sent: Tuesday, October 2, 2018 10:47 AM
Subject: Re: AeroElectric-List: Lycoming Knock Sensor
. . .wouldn't you want to mount the sensors such that their sense axis is in the
same plane as the knock vibration; namely line up with the piston rods and not
on top pf the engine case...?
On Tue, Oct 2, 2018 at 9:09 AM <billhuntersemail@gmail.com<mailto:billhuntersemail@gmail.com>> wrote:
Gentlemen,
Thank you for your reply and sorry for the delay in my reply as I was flying all
day yesterday.
Firstly...THANK YOU for your assistance on this...GREATLY APPRECIATED!!!
I have a Lycoming TIO-540 and I run LOP with balanced injectors.
I understand the concept of one sensor per cylinder and I also understand that
the cylinders on the air-cooled aircraft engine is not as tightly connected to
the engine block as a water cooled engine however sound travels through metal
quite quickly and I would think that the sound would move from each cylinder
head to the block.
Would not one sensor mounted on the crankcase hear the pings?
I can see if I only installed one sensor on the head of cylinder #1 and a pinging
in cylinder #6 would have a long way to travel and the sound would distort
so the sensor would be unreliable for any cylinder other than its installed #1
position.
The Knocksense unit that Bob posted is precisely the one that I was looking at.
I was thinking of buying two units and install them at the top of the engine
with one closer to the front and the second closer to the back. On the Lyco-Saurus
the bottom of the engine has the intake and oil pan so I imagine the liquid
and distance from the source of the sound would dampen out the sound. When
you order them they ask you for your cylinder diameter so they can tune the
sensor to your engine.
The next question ishow do you test to see if the darn thing is working?
Thanks,
Bill Hunter
From: owner-aeroelectric-list-server@matronics.com<mailto:owner-aeroelectric-list-server@matronics.com> <owner-aeroelectric-list-server@matronics.com<mailto:owner-aeroelectric-list-server@matronics.com>> On Behalf Of Robert L. Nuckolls, III
Sent: Monday, October 1, 2018 10:23 AM
Subject: Re: AeroElectric-List: Lycoming Knock Sensor
At 11:51 PM 9/30/2018, you wrote:
I have never heard of a knock sensor on a Lycoming, even one with electronic mags.
I don't see why you couldn't install one in any of the 1/8 NPT primer ports
though.
Knock sensors are specialized microphones
mounted to some sturdy feature of the
crankcase. The device is optimized to
detect 'knock tones' in the 4-6 Khz range
(determined by cylinder bore diameter).
There are no plug-n-play sensors . . . i.e.
devices that will light a bulb when knocking
is detected. They all require some degree
of signal conditioning to separate noises
of interest from the rest. Here's on example
of a product paired with a sensor that
will illuminate an annunciator when knocking
is detected.
https://tinyurl.com/y79tde7s
There is a constellation of Arduino based
sensor detection projects including sample
software
https://tinyurl.com/hsq4mee
This brings to mind another knowledge nugget
I was offered at a Burlington CO fly-in about
15 years ago. The legacy oxygen sensors used
on automobiles have been demonstrated to function
as advertised in 100LL engines. Met a fellow
with an O2 sensor paired with a millivoltmeter
on the panel. He asserted that the sensor had
several hundred hours on it and had not succumbed
to the predicted 'lead fouling' that discouraged
use on aircraft engines.
One might consider an automotive O2 sensor as
an adjunct for achieving consistent mixture
settings. Here's a short article on how they
work:
https://tinyurl.com/ybm74fvh
Bob . . .
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