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Yak Driver
Joined: 09 Mar 2012
Posts: 34
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 Posted: Tue Jan 20, 2015 5:33 pm Post subject: Engine Vibration |
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Hello Yakkers,
My engine has developed a vibration when running my M14P at 80% & 8. It's almost like a drone that comes in every 2 - 3 seconds. At every other power setting it is fine. Has anyone else experienced this before? I have been in touch with Jill who thinks it could be a bent link rod.
Cheers.
[quote][b]
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byronmfox(at)gmail.com
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| Posted: Tue Jan 20, 2015 5:56 pm Post subject: Engine Vibration |
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Of an out of balance prop.
Blitz Fox415-307-2405
On Jan 20, 2015, at 5:30 PM, Anthony Hudacek <antdea2000(at)yahoo.com.au (antdea2000(at)yahoo.com.au)> wrote:
[quote] Hello Yakkers,
My engine has developed a vibration when running my M14P at 80% & 8. It's almost like a drone that comes in every 2 - 3 seconds. At every other power setting it is fine. Has anyone else experienced this before? I have been in touch with Jill who thinks it could be a bent link rod.
Cheers.
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cjpilot710(at)aol.com
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| Posted: Tue Jan 20, 2015 7:12 pm Post subject: Engine Vibration |
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What is the balancing history of the prop? Both static and dynamic? I am not an expert but to me a bent rod would show up at every power setting. And to I've never had any experience with bent rods or what preludes their failure. I know that when doing dynamic balance, it is done at specific RPM, one the operator feel he will spend most time at.
Jim "Pappy' Goolsby
In a message dated 1/20/2015 8:57:05 P.M. Eastern Standard Time, byronmfox(at)gmail.com writes:
| Quote: | Of an out of balance prop.
Blitz Fox 415-307-2405
On Jan 20, 2015, at 5:30 PM, Anthony Hudacek <antdea2000(at)yahoo.com.au (antdea2000(at)yahoo.com.au)> wrote:
| Quote: | Hello Yakkers,
My engine has developed a vibration when running my M14P at 80% & 8. It's almost like a drone that comes in every 2 - 3 seconds. At every other power setting it is fine. Has anyone else experienced this before? I have been in touch with Jill who thinks it could be a bent link rod.
Cheers.
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"http://www.mypilotstore.com/">www.mypilotstore.com
://www.mrrace.com/">www.mrrace.com
tp://www.matronics.com/contribution">http://www.matronics.com/contribution
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k2(at)tulsaconnect.com
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| Posted: Tue Jan 20, 2015 7:20 pm Post subject: Engine Vibration |
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Any drone of vibration felt in the cockpit, kinda like a twin engine prop out of sync... is usually due to, say, an airframe problem... too much slop in a trim tab.
Or to a prop problem.. like a blade angle getting out of sync..
My first guess is to check the blade counterweighs which may be a little tight, due to needed lubrication.. or a slight difference in bolt torque on those counterweights which may cause a sticking blade not to follow the other..
One time, after shipment, a crew failed to turn in on blade that last millimeter to bottom one blade.
When you search for someone to provide a dynamic prop balance, be sure to find someone with lots of experience...
Its rather easy to do a Pratt 1340 which usually has a tight planetary prop reduction system.
Most respond well and are predictable..
But M14 engines can be all over the place...
The frequency sidebands can confuse the balancing equipment easily.
I don’t post here often... But Monty Barrett and Allen know me..
Tulsa Oklahoma a number of Yaks & Cj’s.. Not writing about me but, Some Mechanics here are very good and know the models well.
regards.
Kent Felkins
Tulsa
From: Byron Fox (byronmfox(at)gmail.com)
Sent: Tuesday, January 20, 2015 19:54 PM
To: yak-list(at)matronics.com (yak-list(at)matronics.com)
Subject: Re: Engine Vibration
Of an out of balance prop.
Blitz Fox 415-307-2405
On Jan 20, 2015, at 5:30 PM, Anthony Hudacek <antdea2000(at)yahoo.com.au (antdea2000(at)yahoo.com.au)> wrote:
[quote] Hello Yakkers,
My engine has developed a vibration when running my M14P at 80% & 8. It's almost like a drone that comes in every 2 - 3 seconds. At every other power setting it is fine. Has anyone else experienced this before? I have been in touch with Jill who thinks it could be a bent link rod.
Cheers.
| Quote: |
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uilthelp.com
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otstore.com
matronics.com/contribution
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cs.com
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href="http://www.aeroelectric.com">www.aeroelectric.com
href="http://www.buildersbooks.com">www.buildersbooks.com
href="http://www.homebuilthelp.com">www.homebuilthelp.com
href="http://www.mypilotstore.com">www.mypilotstore.com
href="http://www.mrrace.com">www.mrrace.com
href="http://www.matronics.com/contribution">http://www.matronics.com/chref="http://www.matronics.com/Navigator?Yak-List">http://www.matronics.com/Navigator?Yak-List
href="http://forums.matronics.com">http://forums.matronics.com
[b]
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jill(at)m-14p.com
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| Posted: Wed Jan 21, 2015 4:51 am Post subject: Engine vibration |
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Anthony & Group,
I advised having someone with a dynamic balancer check for anomalies on the
crank vibration based upon the vibration only occurring at the RPM/MP
combination. If the balancer has two pickup points, it can check for this.
Of course, you would perform a dynamic balance of the prop and that would be
the starting point anyway. If there is a prop out of balance vibration, it
typically never goes away. Could there be a blade out of track producing a
harmonic that seems like a vibration? Perhaps.
Anthony, it would be helpful if you could fill in the blanks for the group
regarding conditions in which this problem started? How much of a vibration
is it? etc, etc...anything that can help sleuth out the problem.
As an aside, our B&C Specialty promo on the SK35 alternator has been wildly
successful. I sold out of the alternators I bought for my stock and will be
placing one more large order before the promo ends on 1/31/15. The
alternator/regulator combo is $728. Matt Dralle of the Yaklist has reaped
some reward - $80 from sales on this list. : )
Jill
M-14P, Inc.
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rocknpilot(at)hotmail.com
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| Posted: Wed Jan 21, 2015 5:47 am Post subject: Engine Vibration |
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I also have what is described below - a slowly-oscillating vibration that peaks and subsides in 2 -3 seconds - also at 80%. Nothing else like it at any other setting...
Rico Jaeger
915 S. 11th Ave.
Wausau, WI. 54401
715.529.7426
//
1966 Cessna 150F ^/---//-X
N8558G //Hangar #35 / AUW
//
1992 Yakovlev Yak 52 ^/---//-X
N21YK //
Hangar #21 / AUW
From: k2(at)tulsaconnect.com
To: yak-list(at)matronics.com
Subject: Re: Engine Vibration
Date: Tue, 20 Jan 2015 21:19:51 -0600
Any drone of vibration felt in the cockpit, kinda like a twin engine prop out of sync... is usually due to, say, an airframe problem.. too much slop in a trim tab.
Or to a prop problem.. like a blade angle getting out of sync..
My first guess is to check the blade counterweighs which may be a little tight, due to needed lubrication.. or a slight difference in bolt torque on those counterweights which may cause a sticking blade not to follow the other..
One time, after shipment, a crew failed to turn in on blade that last millimeter to bottom one blade.
When you search for someone to provide a dynamic prop balance, be sure to find someone with lots of experience...
Its rather easy to do a Pratt 1340 which usually has a tight planetary prop reduction system.
Most respond well and are predictable..
But M14 engines can be all over the place...
The frequency sidebands can confuse the balancing equipment easily.
I don’t post here often... But Monty Barrett and Allen know me..
Tulsa Oklahoma a number of Yaks & Cj’s.. Not writing about me but, Some Mechanics here are very good and know the models well.
regards.
Kent Felkins
Tulsa
From: Byron Fox (byronmfox(at)gmail.com)
Sent: Tuesday, January 20, 2015 19:54 PM
To: yak-list(at)matronics.com (yak-list(at)matronics.com)
Subject: Re: Engine Vibration
Of an out of balance prop.
Blitz Fox 415-307-2405
On Jan 20, 2015, at 5:30 PM, Anthony Hudacek <antdea2000(at)yahoo.com.au (antdea2000(at)yahoo.com.au)> wrote:
[quote] Hello Yakkers,
My engine has developed a vibration when running my M14P at 80% & 8. It's almost like a drone that comes in every 2 - 3 seconds. At every other power setting it is fine. Has anyone else experienced this before? I have been in touch with Jill who thinks it could be a bent link rod.
Cheers.
| Quote: |
==========
ctric.com
| Quote: | www.buildersbooks.com
uilthelp.com |
otstore.com
matronics.com/contribution
==========
//www.matronics.com/Navigator?Yak-List
==========
cs.com
==========
|
href="http://www.aeroelectric.com">www.aeroelectric.com
href="http://www.buildersbooks.com">www.buildersbooks.com
href="http://www.homebuilthelp.com">www.homebuilthelp.com
href="http://www.mypilotstore.com">www.mypilotstore.com
href="http://www.mrrace.com">www.mrrace.com
href="http://www.matronics.com/contribution">http://www.matronics.com/chref="http://www.matronics.com/Navigator?Yak-List">http://www.matronics.com/Navigator?Yak-List
href="http://forums.matronics.com">http://forums.matronics.com
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_blank">www.aeroelectric.com
" target="_blank">www.buildersbooks.com
="_blank">www.homebuilthelp.com
="_blank">www.mypilotstore.com
ank">www.mrrace.com
="_blank">http://www.matronics.com/contribution
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rget="_blank">http://www.matronics.com/Navigator?Yak-List
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http://forums.matronics.com
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[b]
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GeorgeCoy
Joined: 02 Dec 2010
Posts: 310
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| Posted: Wed Jan 21, 2015 5:58 am Post subject: Engine Vibration |
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Is the manifold pressure close to the pressure altitude?
George
From: owner-yak-list-server(at)matronics.com [mailto:owner-yak-list-server(at)matronics.com] On Behalf Of Rico Jaeger
Sent: Wednesday, January 21, 2015 8:47 AM
To: yak-list(at)matronics.com
Subject: RE: Engine Vibration
I also have what is described below - a slowly-oscillating vibration that peaks and subsides in 2 -3 seconds - also at 80%. Nothing else like it at any other setting...
Rico Jaeger
915 S. 11th Ave.
Wausau, WI. 54401
715.529.7426
//
1966 Cessna 150F ^/---//-X
N8558G //
Hangar #35 / AUW
//
1992 Yakovlev Yak 52 ^/---//-X
N21YK //
Hangar #21 / AUW
From: k2(at)tulsaconnect.com (k2(at)tulsaconnect.com)
To: yak-list(at)matronics.com (yak-list(at)matronics.com)
Subject: Re: Engine Vibration
Date: Tue, 20 Jan 2015 21:19:51 -0600
Any drone of vibration felt in the cockpit, kinda like a twin engine prop out of sync... is usually due to, say, an airframe problem... too much slop in a trim tab.
Or to a prop problem.. like a blade angle getting out of sync..
My first guess is to check the blade counterweighs which may be a little tight, due to needed lubrication.. or a slight difference in bolt torque on those counterweights which may cause a sticking blade not to follow the other..
One time, after shipment, a crew failed to turn in on blade that last millimeter to bottom one blade.
When you search for someone to provide a dynamic prop balance, be sure to find someone with lots of experience...
Its rather easy to do a Pratt 1340 which usually has a tight planetary prop reduction system.
Most respond well and are predictable..
But M14 engines can be all over the place...
The frequency sidebands can confuse the balancing equipment easily.
I don’t post here often... But Monty Barrett and Allen know me..
Tulsa Oklahoma a number of Yaks & Cj’s.. Not writing about me but, Some Mechanics here are very good and know the models well.
regards.
Kent Felkins
Tulsa
From: Byron Fox (byronmfox(at)gmail.com)
Sent: Tuesday, January 20, 2015 19:54 PM
To: yak-list(at)matronics.com (yak-list(at)matronics.com)
Subject: Re: Engine Vibration
Of an out of balance prop.
Blitz Fox
415-307-2405
On Jan 20, 2015, at 5:30 PM, Anthony Hudacek <antdea2000(at)yahoo.com.au (antdea2000(at)yahoo.com.au)> wrote:
| Quote: |
Hello Yakkers,
My engine has developed a vibration when running my M14P at 80% & 8. It's almost like a drone that comes in every 2 - 3 seconds. At every other power setting it is fine. Has anyone else experienced this before? I have been in touch with Jill who thinks it could be a bent link rod.
Cheers.
| Quote: | | ==========ctric.com>www.buildersbooks.comuilthelp.comotstore.com matronics.com/contribution========== |
01234
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5678901234
567890123456789
012345678901234567890123456789
[quote][b]
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McFly
Joined: 21 May 2012
Posts: 101
Location: Scottsdale, AZ
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| Posted: Wed Jan 21, 2015 6:18 am Post subject: Engine Vibration |
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I was told that the Yak 50 with the V-530 having a slow harmonic "pulse" is very common around 80% and is the engine / prop / airframe interaction causing a harmonic "wave" through the airframe.
Not sure if it is true but is what I was told.
Of course if it didn't do it before would check it out. Also if there was some "event" that precluded it would be interesting.
Todd McCutchanT-34A & Yak-50
Cell: (260) 402-1740
E-mail: todd(at)fastaircraft.com (todd(at)fastaircraft.com)
www.fastaircraft.com
On Jan 21, 2015, at 6:47 AM, Rico Jaeger <rocknpilot(at)hotmail.com (rocknpilot(at)hotmail.com)> wrote:
[quote] I also have what is described below - a slowly-oscillating vibration that peaks and subsides in 2 -3 seconds - also at 80%. Nothing else like it at any other setting...
Rico Jaeger
915 S. 11th Ave.
Wausau, WI. 54401
715.529.7426
//
1966 Cessna 150F ^/---//-X
N8558G //Hangar #35 / AUW
//
1992 Yakovlev Yak 52 ^/---//-X
N21YK //
Hangar #21 / AUW
From: k2(at)tulsaconnect.com (k2(at)tulsaconnect.com)
To: yak-list(at)matronics.com (yak-list(at)matronics.com)
Subject: Re: Engine Vibration
Date: Tue, 20 Jan 2015 21:19:51 -0600
Any drone of vibration felt in the cockpit, kinda like a twin engine prop out of sync... is usually due to, say, an airframe problem... too much slop in a trim tab.
Or to a prop problem.. like a blade angle getting out of sync..
My first guess is to check the blade counterweighs which may be a little tight, due to needed lubrication.. or a slight difference in bolt torque on those counterweights which may cause a sticking blade not to follow the other..
One time, after shipment, a crew failed to turn in on blade that last millimeter to bottom one blade.
When you search for someone to provide a dynamic prop balance, be sure to find someone with lots of experience...
Its rather easy to do a Pratt 1340 which usually has a tight planetary prop reduction system.
Most respond well and are predictable..
But M14 engines can be all over the place...
The frequency sidebands can confuse the balancing equipment easily.
I don’t post here often... But Monty Barrett and Allen know me..
Tulsa Oklahoma a number of Yaks & Cj’s.. Not writing about me but, Some Mechanics here are very good and know the models well.
regards.
Kent Felkins
Tulsa
From: Byron Fox (byronmfox(at)gmail.com)
Sent: Tuesday, January 20, 2015 19:54 PM
To: yak-list(at)matronics.com (yak-list(at)matronics.com)
Subject: Re: Engine Vibration
Of an out of balance prop.
Blitz Fox 415-307-2405
On Jan 20, 2015, at 5:30 PM, Anthony Hudacek <antdea2000(at)yahoo.com.au (antdea2000(at)yahoo.com.au)> wrote:
[b]
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_________________
Todd McCutchan
Fast Aircraft
T-34A - N134FA
KDVT Hangar 33-13
Cell - 260.402.1740
Email: todd@fastaircraft.com
Skype: tmccutchan
Web: www.fastaircraft.com & www.flyams.com |
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rocknpilot(at)hotmail.com
Guest
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| Posted: Wed Jan 21, 2015 7:04 am Post subject: Engine Vibration |
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Todd's description was the best yet of something very difficult to accurately and adequately put into words. ("Harmonic Wave" Love it!) THAT is what it feels like - an airframe "resonance" which occurs only under specific settings - a lot like singing in the shower (NEVER COUNTRY!) and certain pitches appear to be amplified by the shape of the shower shell. Nothing precluded the vibrations I'm detecting, but I only have about 90 personal hours on my aircraft.
Rico Jaeger
915 S. 11th Ave.
Wausau, WI. 54401
715.529.7426
//
1966 Cessna 150F ^/---//-X
N8558G //Hangar #35 / AUW
//
1992 Yakovlev Yak 52 ^/---//-X
N21YK //
Hangar #21 / AUW
From: todd(at)fastaircraft.com
Subject: Re: Engine Vibration
Date: Wed, 21 Jan 2015 06:57:45 -0700
To: yak-list(at)matronics.com
I was told that the Yak 50 with the V-530 having a slow harmonic "pulse" is very common around 80% and is the engine / prop / airframe interaction causing a harmonic "wave" through the airframe.
Not sure if it is true but is what I was told.
Of course if it didn't do it before would check it out. Also if there was some "event" that precluded it would be interesting.
Todd McCutchanT-34A & Yak-50
Cell: (260) 402-1740
E-mail: todd(at)fastaircraft.com (todd(at)fastaircraft.com)
www.fastaircraft.com
On Jan 21, 2015, at 6:47 AM, Rico Jaeger <rocknpilot(at)hotmail.com (rocknpilot(at)hotmail.com)> wrote:
[quote] I also have what is described below - a slowly-oscillating vibration that peaks and subsides in 2 -3 seconds - also at 80%. Nothing else like it at any other setting...
Rico Jaeger
915 S. 11th Ave.
Wausau, WI. 54401
715.529.7426
//
1966 Cessna 150F ^/---//-X
N8558G //Hangar #35 / AUW
//
1992 Yakovlev Yak 52 ^/---//-X
N21YK //
Hangar #21 / AUW
From: k2(at)tulsaconnect.com (k2(at)tulsaconnect.com)
To: yak-list(at)matronics.com (yak-list(at)matronics.com)
Subject: Re: Engine Vibration
Date: Tue, 20 Jan 2015 21:19:51 -0600
Any drone of vibration felt in the cockpit, kinda like a twin engine prop out of sync... is usually due to, say, an airframe problem.. too much slop in a trim tab.
Or to a prop problem.. like a blade angle getting out of sync..
My first guess is to check the blade counterweighs which may be a little tight, due to needed lubrication.. or a slight difference in bolt torque on those counterweights which may cause a sticking blade not to follow the other..
One time, after shipment, a crew failed to turn in on blade that last millimeter to bottom one blade.
When you search for someone to provide a dynamic prop balance, be sure to find someone with lots of experience...
Its rather easy to do a Pratt 1340 which usually has a tight planetary prop reduction system.
Most respond well and are predictable..
But M14 engines can be all over the place...
The frequency sidebands can confuse the balancing equipment easily.
I don’t post here often... But Monty Barrett and Allen know me..
Tulsa Oklahoma a number of Yaks & Cj’s.. Not writing about me but, Some Mechanics here are very good and know the models well.
regards.
Kent Felkins
Tulsa
From: Byron Fox (byronmfox(at)gmail.com)
Sent: Tuesday, January 20, 2015 19:54 PM
To: yak-list(at)matronics.com (yak-list(at)matronics.com)
Subject: Re: Engine Vibration
Of an out of balance prop.
Blitz Fox 415-307-2405
On Jan 20, 2015, at 5:30 PM, Anthony Hudacek <antdea2000(at)yahoo.com.au (antdea2000(at)yahoo.com.au)> wrote:
===========
_blank">www.aeroelectric.com
" target="_blank">www.buildersbooks.com
="_blank">www.homebuilthelp.com
="_blank">www.mypilotstore.com
ank">www.mrrace.com
="_blank">http://www.matronics.com/contribution
===========
rget="_blank">http://www.matronics.com/Navigator?Yak-List
===========
http://forums.matronics.com
===========
[b]
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Penco
Joined: 14 Dec 2018
Posts: 7
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| Posted: Wed Mar 27, 2019 3:04 am Post subject: Re: Engine Vibration |
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Hello guys, I'm reviving this topic because I'm coming short of an explanantion.
Bit of history :
Bought the aircraft last year. It worked fine and then, some 5 month ago (didn't fly with it since) started to develop a strong vibration at higher RPM only.
We had the prop balanced and even tried another one, we upgraded the spark plugs to the automotive kit. It made a definitive improvement to engine start, pickup time etc (gotta adjust the idle now). But that damn shaking is still there.
The engine is basically smooth until 70-72% RPM and then vigourously starts to shake (I didn't really try above 90%). The weird part ? Sometimes, after I try lower power settings and the go back up in power, it doesn't. And then, picks it up again.
I'm a little desperate for an explanation here. It's an old engine with low time remaining on it but still, I'd like an explanation, be it just for educational purposes.
Many thanks,
Penco
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dsavarese0812(at)bellsout
Guest
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| Posted: Wed Mar 27, 2019 5:06 am Post subject: Engine Vibration |
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Does the vibration exist with and without the cowling installed? How old are the engine mount rubber shock mounts? Have you inspected all 8 of them on both sides very carefully along with the bolts and nuts? Have you looked closely at the engine mount ring, tabs, bolts/nuts, arms, attach points on the arms and the firewall?
Dennis
On Wednesday, March 27, 2019, 7:06:57 AM EDT, Penco <osipenco(at)gmail.com> wrote:
--> Yak-List message posted by: "Penco" <osipenco(at)gmail.com (osipenco(at)gmail.com)>
Hello guys, I'm reviving this topic because I'm coming short of an explanantion.
Bit of history :
Bought the aircraft last year. It worked fine and then, some 5 month ago (didn't fly with it since) started to develop a strong vibration at higher RPM only.
We had the prop balanced and even tried another one, we upgraded the spark plugs to the automotive kit. It made a definitive improvement to engine start, pickup time etc (gotta adjust the idle now). But that damn shaking is still there.
The engine is basically smooth until 70-72% RPM and then vigourously starts to shake (I didn't really try above 90%). The weird part ? Sometimes, after I try lower power settings and the go back up in power, it doesn't. And then, picks it up again.
I'm a little desperate for an explanation here. It's an old engine with low time remaining on it but still, I'd like an explanation, be it just for educational purposes.
Many thanks,
Penco
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Penco
Joined: 14 Dec 2018
Posts: 7
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| Posted: Wed Mar 27, 2019 5:22 am Post subject: Re: Engine Vibration |
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Hello Dennis,
The engine vibrates whether or not the cowlings are installed.
I didn't check the rubber mounts, I figured if they would be damaged it would shake at all RPM...
Any specific things I should look for when inspecting them ?
Cheers,
Penco
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GeorgeCoy
Joined: 02 Dec 2010
Posts: 310
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| Posted: Wed Mar 27, 2019 5:27 am Post subject: Engine Vibration |
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I presume you have done the usual compression checks.
Have you removed the rocker covers and looked for broken valve
springs? Have you checked the rocker clearances recently.
As it happens around 70%, that is about where the manifold pressure
goes from vacuum to pressure. Carefully check the intake manifold and
various connections for leaks. Pay particular attention to where the intake
pipes screw into the cylinders and the manifold.
If you have one of the original Russian top dead center tools or can
borrow one, put a 1/4 inch spacer on it and screw it in front plug hole on
and cylinders 4,5 & 6 to check for possible hydrolock.
George Coy
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dsavarese0812(at)bellsout
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| Posted: Wed Mar 27, 2019 5:45 am Post subject: Engine Vibration |
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Yes, dry rot; cracking; protruding out beyond the end plates. Look for sagging too. Look in your engine log book and see if you can figure out how long ago they were changed.
Don't forget to carefully inspect the engine mount and all attach points.
Check for loose accessories attached to the engine. ie: Generator? etc.
Check the cooling louver ring, individual louvers and attach points of the adjustable arms for looseness.
Dennis
On Wednesday, March 27, 2019, 9:24:35 AM EDT, Penco <osipenco(at)gmail.com> wrote:
--> Yak-List message posted by: "Penco" <osipenco(at)gmail.com (osipenco(at)gmail.com)>
Hello Dennis,
The engine vibrates whether or not the cowlings are installed.
I didn't check the rubber mounts, I figured if they would be damaged it would shake at all RPM...
Any specific things I should look for when inspecting them ?
Cheers,
Penco
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=488286#488286
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romaine_richard(at)yahoo.
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| Posted: Thu Mar 28, 2019 4:47 am Post subject: Engine Vibration |
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Has anyone ever looked at doing urethane mounts...or is the thinking they’d be too stiff or not survive the environment?
Rich
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Penco
Joined: 14 Dec 2018
Posts: 7
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| Posted: Wed Apr 03, 2019 10:30 am Post subject: Re: Engine Vibration |
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Hey guys, update on the thing.
It turned out that (pardon me for the lack of technical terms) the screw on top of the intake valve's push rod of cylindre 9 was completely loose. Preventing it from firing.
After retightening and checking the spacing of the valve, everything runs smooth again.
It got me a little flabergasted, I have NO IDEA how that thing came loose.
The more you know...
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dsavarese0812(at)bellsout
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| Posted: Wed Apr 03, 2019 11:18 am Post subject: Engine Vibration |
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There are 4 cam lobes on the intake cam plate and 4 lobes on the exhaust cam plate. You will need to adjust the valve 4 times because each time you rotate the prop and open the same intake valve, a different cam lobe will open the same intake valve.
Dennis
On Wednesday, April 3, 2019, 2:33:12 PM EDT, Penco <osipenco(at)gmail.com> wrote:
--> Yak-List message posted by: "Penco" <osipenco(at)gmail.com (osipenco(at)gmail.com)>
Hey guys, update on the thing.
It turned out that (pardon me for the lack of technical terms) the screw on top of the intake valve of cylindre 9 was completely loose. Preventing it from firing.
After retightening and checking the spacing of the valve, everything runs smooth again.
It got me a little flabergasted, I have NO IDEA how that thing came loose.
The more you know..
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=488484#488484
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GeorgeCoy
Joined: 02 Dec 2010
Posts: 310
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| Posted: Wed Apr 03, 2019 2:01 pm Post subject: Engine Vibration |
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Tine to check all the valve clearances.
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dsavarese0812(at)bellsout
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| Posted: Wed Apr 03, 2019 2:16 pm Post subject: Engine Vibration |
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Great minds think alike! 
Dennis
On Wednesday, April 3, 2019, 6:03:56 PM EDT, George Coy <george.coy(at)gmail.com> wrote:
--> Yak-List message posted by: "George Coy" <george.coy(at)gmail.com (george.coy(at)gmail.com)>
Tine to check all the valve clearances.
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wlannon(at)shaw.ca
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| Posted: Wed Apr 03, 2019 8:42 pm Post subject: Engine Vibration |
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Some very good advice from Dennis and George.
If you have not done this before you will find that in adjusting the EXHAUST
valve clearance it is necessary to rotate the engine to open the valve
enough to provide clearance for the special wrench to properly engage the
nut.
If adjustment is needed the process is "check, turn, loosen, return to TDC,
adjust, turn, tighten, return and re-check". It is a process that requires
the utmost attention to detail. Fortunately not required for the intake
valve!
The only engine I know of worse than this is the R1340 (Pratt & Whitney's
first engine) which has a "floating" cam ring and a valve adjusting
procedure from hell!
Walt
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