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CHT & EGT control

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NeilsenRM(at)comcast.net
Guest

Posted: Thu Aug 09, 2007 1:26 pm Post subject: CHT & EGT control

I wonder about this also. I don't have a EGT gage. I know my mixture is 

correct from reading my plugs and my Oil & CHT temps are fine so what do I 

care about EGTs. If I was leaning my mixture in flight I understand that it 

gives me a early warning about going too lean that is fine but I don't do 

that because I don't have in flight adjustable carbs.  If I were to unload 

the prop in the air I understand that the EGTs will go up but again why 

would I care. If heat isn't being absorbed by my engine with in limits and 

my other temps stay in a working range isn't that a good thing?



Rick Neilsen

Redrive VW Powered MKIIIC

---

John Hauck

Joined: 09 Jan 2006
Posts: 4639
Location: Titus, Alabama (hauck's holler)

Posted: Thu Aug 09, 2007 3:10 pm Post subject: CHT & EGT control

Rick:



Not on a 4 stroke.  Unloading the engine only applies to 2 strokes.



john h



 

   If I were to unload 

the prop in the air I understand that the EGTs will go up  



Rick Neilsen

_________________
John Hauck
MKIII/912ULS
hauck's holler
Titus, Alabama

d-m-hague(at)comcast.net
Guest

Posted: Thu Aug 09, 2007 6:14 pm Post subject: CHT & EGT control

At 04:33 PM 8/9/2007, jb92563 wrote:



 	  Quote: 	
		  I figure the most important is the CHT and I figure that throttleing down 

is the way to cool things down a bit if you start to overheat?


	


Unless your carb is screwed up and running too lean in the midrange, then 

throttling back could make it even worse...



                                 -Dana

--

--

"The budget should be balanced, the Treasury should be refilled, public

debt should be reduced, the arrogance of officialdom tempered and

controlled, and the assistance to foreign lands should be curtailed lest

Rome become bankrupt" -Cicero, 68 B.C.

icrashrc

Joined: 16 Mar 2006
Posts: 247
Location: Mishawaka, In

Posted: Fri Aug 10, 2007 4:49 am Post subject: Re: CHT & EGT control

Trust me. Your exhaust valves, seats, and guides care what the EGT's are.

_________________
Scott

www.ill-EagleAviation.com

do not archive

jindoguy(at)gmail.com
Guest

Posted: Fri Aug 10, 2007 6:54 am Post subject: CHT & EGT control

I don't have a four stroke on a Kolb, yet, but the HKS on my trike can definitely be unloaded and just like a two stroke, CHT goes down and EGT goes up.

I think the difference here is that the trike has variable angle of incidence unlike a conventional aircraft. 



Rick



do not archive



On 8/9/07, Dana Hague <d-m-hague(at)comcast.net (d-m-hague(at)comcast.net)> wrote:[quote] --> Kolb-List message posted by: Dana Hague <d-m-hague(at)comcast.net (d-m-hague(at)comcast.net)>



At 04:33 PM 8/9/2007, jb92563 wrote:



 	  Quote: 	
		  I figure the most important is the CHT and I figure that throttleing down 

is the way to cool things down a bit if you start to overheat?


	


Unless your carb is screwed up and running too lean in the midrange, then

throttling back could make it even worse...



                                 -Dana 

--

--

"The budget should be balanced, the Treasury should be refilled, public

debt should be reduced, the arrogance of officialdom tempered and

controlled, and the assistance to foreign lands should be curtailed lest 

"Ya'll drop on in"

takes on a whole new meaning

when you live at the airport.  [quote][b]

NeilsenRM(at)comcast.net
Guest

Posted: Fri Aug 10, 2007 10:30 am Post subject: CHT & EGT control

Richard

  

 Thanks for the input. I figured the EGT would go up  like it does in a 2 stroke. 

  

 As for your comment about "variable  angle of incidence" not available in a regular  aircraft? I think you fail to understand the fact that both types of  aircraft have the ability and need for changing the angle of incidence. You do  that by shifting your weight and we do it by elevator  deflection.

  

 Rick Neilsen

 Redrive VW Powered MKIIIC 

  

 [quote]   ---

jindoguy(at)gmail.com
Guest

Posted: Fri Aug 10, 2007 5:47 pm Post subject: CHT & EGT control

Blame it on the heat. What I meant was variable thrust line. The angle between the thrust line and the wing is fixed on a Kolb, or other conventional airplane (yes I know about the F8U and the A7 which could jack up the angle of incidence, but I don't know of any others).  

On a trike, the wing is free to move in pitch and roll, while the thrust line to the carriage (the trike part) is fixed.

Hope that makes more sense.



Rick



Do not archive



 On 8/10/07, Richard & Martha Neilsen <NeilsenRM(at)comcast.net (NeilsenRM(at)comcast.net)> wrote:[quote]        Richard

  

 Thanks for the input. I figured the EGT would go up  like it does in a 2 stroke. 

  

 As for your comment about "variable  angle of incidence" not available in a regular  aircraft? I think you fail to understand the fact that both types of  aircraft have the ability and need for changing the angle of incidence. You do  that by shifting your weight and we do it by elevator  deflection.

  

 Rick Neilsen

 Redrive VW Powered MKIIIC 

  

 [quote]   ---

Jim Baker

Joined: 30 Mar 2006
Posts: 181
Location: Sayre, PA

Posted: Fri Aug 10, 2007 7:37 pm Post subject: CHT & EGT control

 	  Quote: 	
		   

 Trust me. Your exhaust valves, seats, and guides care what the EGT's are.   


	


Well, sort of...but not in the way you're thinking....



http://www.warmkessel.com/jr/flying/td/jd/59.jsp



Jim Baker

580.788.2779

Elmore City, OK

lndc

Joined: 15 Jan 2006
Posts: 9
Location: northern MN

Posted: Sat Aug 11, 2007 2:17 pm Post subject: Re: CHT & EGT control

Rick, You fly a 4 stroke right? I fly a continental now but used to fly a 2 stroke. If your cyl head temp is high and your egt is low means that you have way too much prop. the opposite would be just that, Too little prop pitch. Get a CPS catalog and tune that 2 stroke. All the info is in the back of the catalog. My A65 is easy. If you get full rpms its good to go. 

Dan Charter

northern MN

Ed in JXN

Joined: 24 Mar 2006
Posts: 122

Posted: Sat Aug 11, 2007 8:13 pm Post subject: CHT & EGT control

Hi Rick,

  

         I believe you  mean Angle of Attack.  Angle of Incidence is fixed on most  aircraft.

  

         Good seeing  you and Hauck at OSH>

  

 Ed in JXN

 MkII/503

 Do not archive.

  

 [quote]   ---

jindoguy(at)gmail.com
Guest

Posted: Sun Aug 12, 2007 5:33 am Post subject: CHT & EGT control

Ed, No, angle of attack is defined, if I remember my ground school training correctly, and I offer no guarantees, as the angle between the wing and the relative wind, which does change with elevator  movement. 

Thrust line, on airplanes, is fixed, with the exceptions noted. On trikes, with the wing free to move in the pitch axis, it is not. 

I used this ability coming back from the Vintage Aircraft Fly In at Halstead, KS, yesterday. I allowed CHT to get to 310 degrees climbing to 2500 feet, then cruised at 4800 RPM instead of the usual 4700 so I could unload the prop and cool the heads. When the CHT's came down to 295 I decreased the RPM to normal cruise. It doesn't sound like much change, but it works. 

Although the normal cruise speed of the trike is 42, I use 48 to 50 for approach for better control. If I'm making a power off approach, the prop is driven to a higher RPM than the throttle is set for, and CHT plummets as a result of less heat from burning fuel and the unloading of the prop. 

If I make a power on approach at 3700 RPM the load on the prop is stabilized and CHT's remain stable until I chop power once I'm well into ground effect.



Rick



PS I also learned something new yesterday. Nothing increases the intensity of your vision scan like seeing a KC135 go under you. 



Do not archive

On 8/11/07, Ed Chmielewski <edchmiel(at)mindspring.com (edchmiel(at)mindspring.com)> wrote:[quote]         

 Hi Rick,

  

         I believe you  mean Angle of Attack.  Angle of Incidence is fixed on most  aircraft.

  

         Good seeing  you and Hauck at OSH>

  

 Ed in JXN

 MkII/503

 Do not archive.

  

 [quote]   ---

Ed in JXN

Joined: 24 Mar 2006
Posts: 122

Posted: Sun Aug 12, 2007 6:19 pm Post subject: CHT & EGT control

Hi Rick,

  

         "I think  you fail to understand the fact that both types of aircraft have the  ability and need for changing the angle of incidence. You do that by shifting  your weight and we do it by elevator deflection."  

         You're not  changing the aircraft angle of incidence (fixed-wing) by moving the  elevator. I'm not sure about angle of incidence on a trike being fixed or  not.  Being fixed on a pivot, I'd guess it is fixed.

          

         "Thrust line, on airplanes, is fixed, with the  exceptions noted. On trikes, with the wing free to move in the pitch axis, it is  not."

   On any aircraft with a hard-mounted engine,  thrust line is fixed.  You might change the relative angle (by using  elevator and thus AOA - fixed wing - or moving the trike wing angle - again  AOA).  The tilt-rotor V-22 Osprey is an example of variable thrust line and  wing AOA combined.  

         You're  correct about the definition of AOA, BTW.

  

 Ed in JXN

 MkII/503

  

  

 [quote]   ---

pj.ladd(at)btinternet.com
Guest

Posted: Mon Aug 13, 2007 12:46 am Post subject: CHT & EGT control

PS I also learned something new yesterday. Nothing  increases the intensity

of your vision scan like seeing a KC135 go under  you>>

  

 Hi,

  

 Try a Harrier when you are less than 1000ft above  ground and you can see the top of the pilots head but cannot see his  wingman.

  

 Cheers

  

 Pat

  

 do not archive

   [quote][b]

jindoguy(at)gmail.com
Guest

Posted: Mon Aug 13, 2007 5:42 am Post subject: CHT & EGT control

No thanks, Pat. That big tanker was enough for me. He came in about 45 degrees to my left rear and I didn't see him until he passed under. They normally travel in pairs, too, and sure enough I picked up the other when he turned crosswind. Quite an experience watching him close. My 31 mph ground speed and his 300. After that I decided the nice cool air above the inversion layer wasn't worth it and dropped down into the heat. 



Rick



On 8/13/07, pat ladd <pj.ladd(at)btinternet.com (pj.ladd(at)btinternet.com)> wrote:[quote]        PS I also learned something new yesterday. Nothing  increases the intensity

of your vision scan like seeing a KC135 go under  you>>

  

 Hi,

  

 Try a Harrier when you are less than 1000ft above  ground and you can see the top of the pilots head but cannot see his  wingman.

  

 Cheers

  

 Pat

  

 do not archive

   [quote][b]  http://www.matronics.com/Navigator?Kolb-List http://forums.matronics.com 

when you live at the airport.  [quote][b]

pj.ladd(at)btinternet.com
Guest

Posted: Mon Aug 13, 2007 8:47 am Post subject: CHT & EGT control

After that I decided the nice cool air above the  inversion layer wasn't worth it and dropped down into the  heat.>>

  

 Hi Richard,

 they can get you anywhere.  Apart from my  Harrier experience, I was once , learning to fly gliders, chased up the launch  wire by a Hercules. I was with an instructor and we dropped the cable at around  1000ft just as a Herc overtook us underneath.. Just to one side luckily or we  would have dropped the wire into his props. That would have made his eyes  water.

 I met a friendthe other day who I had known since  gliding days. He too graduated to ultralights, a Rans, and when I asked him how  the flying was going he replied.

 " I have packed  it in. Its too damn dangerous"  Now I knew that he had dived into  the ground from aroun 10ft when a pin connecting the controls to the elevator  dropped out and he had still carried on flying after that so I asked what had  happened. "A bloody Herc flew under me` he said. Thats rough I commiserated what  height were you?   He went pale at the memory. "I was in  the  f********n circuit"

  

 Cheers

  

 Pat

  

  

   [quote][b]

jindoguy(at)gmail.com
Guest

Posted: Mon Aug 13, 2007 11:44 am Post subject: CHT & EGT control

Pat, Back in the Reagan years I was flying at Little Mtn in Mt. Vernon, WA  thermalling just under cloud base at around 3500' and about a half mile downwind of take off. The wind noise started getting louder and thinking I was flying a bit fast I pushed out a bit, but that made the inside wing tip start to buffet so I increased speed and continued the turn. Suddenly there was an A-7 Corsair II right at my altitude, turning away slightly, going by close enough that I could read the placards on the side of the fuselage, and the pilot was waving at me! He was in my blind spot so I thank the Dear Lord he saw me.  

Never owned a glider without bright red leading edges to this day. Even the trike has bright red leading edges, although the fuselage is only bright yellow. You can never have too much visibility. I'd sure like to know if that 135 driver saw me or if it was just dumb luck. 



Rick



On 8/13/07, pat ladd <pj.ladd(at)btinternet.com (pj.ladd(at)btinternet.com)> wrote:[quote]        After that I decided the nice cool air above the  inversion layer wasn't worth it and dropped down into the  heat.>>

  

 Hi Richard,

 they can get you anywhere.  Apart from my  Harrier experience, I was once , learning to fly gliders, chased up the launch  wire by a Hercules. I was with an instructor and we dropped the cable at around  1000ft just as a Herc overtook us underneath.. Just to one side luckily or we  would have dropped the wire into his props. That would have made his eyes  water.

 I met a friendthe other day who I had known since  gliding days. He too graduated to ultralights, a Rans, and when I asked him how  the flying was going he replied.

 " I have packed  it in. Its too damn dangerous"  Now I knew that he had dived into  the ground from aroun 10ft when a pin connecting the controls to the elevator  dropped out and he had still carried on flying after that so I asked what had  happened. "A bloody Herc flew under me` he said. Thats rough I commiserated what  height were you?   He went pale at the memory. "I was in  the  f********n circuit"

  

 Cheers

  

 Pat

  

  

   [quote][b]  http://www.matronics.com/Navigator?Kolb-List http://forums.matronics.com 

when you live at the airport.  [quote][b]

pj.ladd(at)btinternet.com
Guest

Posted: Tue Aug 14, 2007 1:04 am Post subject: CHT & EGT control

A-7 Corsair II right at my  altitude>>

  

 Isnt it amazing that with all that  sky........

  

 cheers

  

 Pat

   [quote][b]

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