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Noise on runup

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n616tb(at)btsapps.com
Guest

Posted: Sun Apr 01, 2007 3:13 pm Post subject: Noise on runup

I would be looking for marks on the cowl or back of spinner.  If need be one could shoot some light primer around suspect areas and then recheck for scuffing.  You didn’t mention if this was a 6 or 6A, or maybe you do by omitting the (A).  The comment here is be cautious with doing maximum RPM static run-ups as I have heard it can nose over.  

   

Just ideas  

Tim  

           

  

From: owner-rv-list-server(at)matronics.com [mailto:owner-rv-list-server(at)matronics.com] On Behalf Of FRANCIS MALCZYNSKI

 Sent: Sunday, April 01, 2007 5:08 PM

 To: RV-List Digest Server

 Subject: Noise on runup  

  

       

I have a friend who has comleted his RV6 and is ready to fly. However, when he does a static runup to check maximum RPM, he gets a rythmic noise that sounded to be like a resonant vibration of the engine hitting the inside of the cowl. The noise starts at about 2000 RPM. It is very loud and cannot be mistaken. Other people have heard it and described it as a whaa, whaa, whaa (can you aurilize this?) but again very loud. Any idea whats going on. The engine is a rebuilt 0320, 160hp, fuel injected running a 69 x 72 Performance Propeller. Could it be valve float?

 

 Any and all facts or thories would be appreciated.

 

 Thanks

 

 Fran Malczynski

 RV6 - N594EF

 Olcott, NY

 

 

   

  

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Vanremog(at)aol.com
Guest

Posted: Sun Apr 01, 2007 4:01 pm Post subject: Noise on runup

In a message dated 4/1/2007 3:10:52 P.M. Pacific Daylight Time,  airfran(at)verizon.net writes:

  	  Quote: 	
		  I have a friend who has completed his RV6 and is ready to fly. However,    when he does a static runup to check maximum RPM, he gets a rhythmic noise    that sounded to be like a resonant vibration of the engine hitting the inside    of the cowl. 	


 

 ===========================================

  

 Alternator, exhaust pipe or airbox hitting against cowling?   

 GV (RV-6A N1GV O-360-A1A, C/S, Flying 840hrs, Silicon Valley,  CA)



See what's free at AOL.com. 

  [quote][b]

George McNutt

Joined: 09 Jan 2006
Posts: 30

Posted: Sun Apr 01, 2007 4:23 pm Post subject: Noise on runup

Hi Fran



Try a short run up with cowlings off to eliminate engine hitting cowling 

(don't fry the cylinder)s.

How is the alignment of the alternator belt pulleys??



George in Langley BC



FRANCIS MALCZYNSKI wrote:

 	  Quote: 	
		   I have a friend who has comleted his RV6 and is ready to fly. However, 

 when he does a static runup to check maximum RPM, he gets a rythmic 

 noise that sounded to be like a resonant vibration of the engine 

 hitting the inside of the cowl. The noise starts at about 2000 RPM. It 

 is very loud and cannot be mistaken. Other people have heard it and 

 described it as a whaa, whaa, whaa (can you aurilize this?) but again 

 very loud. Any idea whats going on. The engine is a rebuilt 0320, 

 160hp, fuel injected running a 69 x 72 Performance Propeller. Could it 

 be valve float?



 Any and all facts or thories would be appreciated.



 Thanks



 Fran Malczynski

 RV6 - N594EF

 Olcott, NY



 *

 *

ceengland(at)bellsouth.ne
Guest

Posted: Sun Apr 01, 2007 4:31 pm Post subject: Noise on runup

FRANCIS MALCZYNSKI wrote:

 	  Quote: 	
		   I have a friend who has comleted his RV6 and is ready to fly. However, 

 when he does a static runup to check maximum RPM, he gets a rythmic 

 noise that sounded to be like a resonant vibration of the engine hitting 

 the inside of the cowl. The noise starts at about 2000 RPM. It is very 

 loud and cannot be mistaken. Other people have heard it and described it 

 as a whaa, whaa, whaa (can you aurilize this?) but again very loud. Any 

 idea whats going on. The engine is a rebuilt 0320, 160hp, fuel injected 

 running a 69 x 72 Performance Propeller. Could it be valve float?

 

 Any and all facts or thories would be appreciated.

 

 Thanks

 

 Fran Malczynski

 RV6 - N594EF

 Olcott, NY


	


 From an old time troubleshooter: Easiest first. Manually flex the prop 

to be sure it doesn't have loose laminations. Check to be sure the 

blades are tracked properly. (Did he check static balance?) Next, remove 

the cowl &  look for rub-points. Then do another runup to see if the 

noise is gone without the cowl in place.



Not trying to offend, but he does have oil pressure, right? (It's 

happened to others...)



Charlie

Hopperdhh(at)aol.com
Guest

Posted: Sun Apr 01, 2007 4:36 pm Post subject: Noise on runup

My advice in addition to that already posted is to be absolutely sure that the engine is not starving for fuel before flying.  I don't think that is the case, but just be sure.

  

 Full throttle runups are worse for vibrations than flying.  If something is hitting you should be able to find it.  The front of the engine moves around more than the rear.  Do you have at least 3/8 inch clearance everywhere?

  

 Dan Hopper

 RV-7A

  



See what's free at AOL.com. 

  [quote][b]

rv8a2001(at)yahoo.com
Guest

Posted: Sun Apr 01, 2007 6:20 pm Post subject: Noise on runup

There is a RV-6 at KSEE in San Diego that does the same thing. I think it also has the 320 and a fixed pitch but dont know which one. It is parked way on the otherside of the airport so I dont know what hanger its in. Every time that plane takes off people just shake there head saying there must be something wrong with it. Its been flying for 3 years this way that I know of.

 

Scott Bilinski

RV-8a

 



  



FRANCIS MALCZYNSKI wrote:

 	  Quote: 	
		   I have a friend who has comleted his RV6 and is ready to fly. However, 

 when he does a static runup to check maximum RPM, he gets a rythmic 

 noise that sounded to be like a resonant vibration of the engine hitting 

 the inside of the cowl. The noise starts at about 2000 RPM. It is very 

 loud and cannot be mistaken. Other people have heard it and described it 

 as a whaa, whaa, whaa (can you aurilize this?) but again very loud. Any 

 idea whats going on. The engine is a rebuilt 0320, 160hp, fuel injected 

 running a 69 x 72 Performance Propeller. Could it be valve float?

 


	






 	     Looking for earth-friendly autos? 

 Browse Top Cars by "Green Rating" at Yahoo! Autos' Green Center.   [quote][b]

Painless

Joined: 10 Jan 2006
Posts: 40
Location: Peshtigo, Wisconsin

Posted: Sun Apr 01, 2007 6:30 pm Post subject: Noise on runup

---

_________________
Jeff Orear
RV6A N782P
Peshtigo, WI

John.Morrissey(at)csiro.a
Guest

Posted: Sun Apr 01, 2007 6:40 pm Post subject: Noise on runup

Hi All,  

This often has something to do with the length of the exhaust stack and how far it is away from the floor. As each beat from the exhaust leave the end of the pipe it expands rapidly and sometimes causes a resonant vibration in the floor.  

Things to try:  

     Add      extensions to the tail pipe  
Glue      some carpet on the floor  
Add      a couple of flat AL      strips across the floor   

All of these could change the resonant frequency of the vibration in the area in question.  

Good lick   

John Morrissey

From: owner-rv-list-server(at)matronics.com [mailto:owner-rv-list-server(at)matronics.com] On Behalf Of scott bilinski

 Sent: Monday, 2 April 2007 12:19 PM

 To: rv-list(at)matronics.com

 Subject: Re: Noise on runup  

There is a RV-6 at KSEE in San   Diego that does the same thing. I think it also has the 320 and a fixed pitch but dont know which one. It is parked way on the otherside of the airport so I dont know what hanger its in. Every time that plane takes off people just shake there head saying there must be something wrong with it. Its been flying for 3 years this way that I know of.

Scott Bilinski

 RV-8a    

 FRANCIS MALCZYNSKI wrote:

 > I have a friend who has comleted his RV6 and is ready to fly. However, 

 > when he does a static runup to check maximum RPM, he gets a rythmic 

 > noise that sounded to be like a resonant vibration of the engine hitting 

 > the inside of the cowl. The noise starts at about 2000 RPM. It is very 

 > loud and cannot be mistaken. Other people have heard it and described it 

 > as a whaa, whaa, whaa (can you aurilize this?) but again very loud. Any 

 > idea whats going on. The engine is a rebuilt 0320, 160hp, fuel injected 

 > running a 69 x 72 Performance Propeller. Could it be valve float?

 >   

Looking for earth-friendly autos? 

 Browse Top Cars by "Green Rating" at Yahoo! Autos' Green Center.    	  Quote: 	
		    http://www.matronics.com/Navigator?RV-List 	
0 	  Quote: 	

1 	  Quote: 	

2 	  Quote: 	

3 	  Quote: 	

4

      [quote][b]

Mark Phillips in TN

Joined: 10 Jan 2006
Posts: 431
Location: Columbia, TN

Posted: Sun Apr 01, 2007 9:52 pm Post subject: Noise on runup

In a message dated 04/01/2007 9:31:47 PM Central Daylight Time, jorear(at)new.rr.com writes:

  	  Quote: 	
		  Any and all facts or thories would be appreciated. 	


 >>>

  

 Vibration of oil-canning bottom skins or rudder?  Might get someone to CAREFULLY look under the plane from behind the wing and press on suspect panels.  Is noise accompanied by vibration sensed in seat or stick?  Just a guess...

  

 Mark - do not archive



See what's free at AOL.com. 

  [quote][b]

_________________
From The PossumWorks...

rembree(at)sympatico.ca
Guest

Posted: Mon Apr 02, 2007 2:38 am Post subject: Noise on runup

I had a resonant vibration that would occur at low power settings in flight. The baffle seal on one side was a bit too short and would flip inside out.  I extended the baffle seal and the problem went away. 

 Roger Embree

 

 

 FRANCIS MALCZYNSKI wrote:

 [quote]         I have a friend who has comleted his RV6 and is ready to fly. However, when he does a static runup to check maximum RPM, he gets a rythmic noise that sounded to be like a resonant vibration of the engine hitting the inside of the cowl. 

   [/b]

   

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