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  #1  
Old 05-06-2014, 03:40 PM
Derek Derek is offline
 
Join Date: Jan 2011
Location: Sydney, Australia
Posts: 86
Default No.1 CHT and EGT lagging and low

Ive recently run and flown my engine (and aircraft) for the first time, the engine was pickled for 2 years.It's a zero timed 0-360 A4M converted to AFP's FI. What was noticable immediately was No.1's CHT and EGT was the last of all the 4 cylinders to rise, way behind the other three and significantly lower in temperature. In the first picture Ive attached you can see that on initial start-up No.1's CHT is 70 degrees lower than all the rest, and you can see that this trend continues in the next photo taken approximately 13 minutes later.

Also No.1 cylinder is fouling the plug during extended periods of idling on the ground, however this can be cleared by leaning.

Lastly....what's noticable after running WOT on the ground then pulling back to idle No1's EGT falls away noticably quicker than the other 3 cylinders.

Is what im experiencing the symptons of a new engine and will settle down once run in or should I be concerned ?




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  #2  
Old 05-06-2014, 04:20 PM
Bill.Peyton's Avatar
Bill.Peyton Bill.Peyton is offline
 
Join Date: Sep 2009
Location: St. Louis, MO
Posts: 1,885
Default

I see that you have let your CHTs go above 400 deg. During your break in period you should alway keep them under 400. Preferably under 380! Keep your ground run ups to a minimum duration. Don't be concerned with your EGTs until you get it broken in. The CHTS will also come down when you get it broken in. I would suspect this will take 10-30 hours depending on how well you maintain the breakin profile called out in the LYCOMING manual. After breakin you can look at equalizing your CHTs using the front air dams, further baffle sealing, etc. you can also flow match the cylinders after break in. Don't worry about the individual EGTs for now. This could be caused by probe calibration or location in the exhaust tube.
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  #3  
Old 05-06-2014, 04:41 PM
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Kahuna Kahuna is online now
 
Join Date: Dec 2004
Location: Gold Hill, NC25
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Given the fouling, its possible that your #1 is excessively rich. When does it peak compared to the others when leaning?
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  #4  
Old 05-06-2014, 04:52 PM
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jdeas jdeas is offline
 
Join Date: Mar 2006
Location: SoCal
Posts: 634
Default Flow problems

Quote:
Originally Posted by Kahuna View Post
Given the fouling, its possible that your #1 is excessively rich. When does it peak compared to the others when leaning?
Check the spread on leaning. Possible fuel flow to #1 is way off the other three. I had the same problem and had to return my flow divider to fix it.
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  #5  
Old 05-06-2014, 05:33 PM
Derek Derek is offline
 
Join Date: Jan 2011
Location: Sydney, Australia
Posts: 86
Default Is this the process ?

Quote:
Originally Posted by Kahuna View Post
Given the fouling, its possible that your #1 is excessively rich. When does it peak compared to the others when leaning?
Thanks for you reply, newbie question just to be sure.

Do I lean progressivly on the ground ( making sure I dont exceed 380 degrees F CHT) and then compare where No.1's CHT is to the other 3 ?
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  #6  
Old 05-06-2014, 05:36 PM
Derek Derek is offline
 
Join Date: Jan 2011
Location: Sydney, Australia
Posts: 86
Default Thanks Bill

Quote:
Originally Posted by Bill.Peyton View Post
I see that you have let your CHTs go above 400 deg. During your break in period you should alway keep them under 400. Preferably under 380! Keep your ground run ups to a minimum duration. Don't be concerned with your EGTs until you get it broken in. The CHTS will also come down when you get it broken in. I would suspect this will take 10-30 hours depending on how well you maintain the breakin profile called out in the LYCOMING manual. After breakin you can look at equalizing your CHTs using the front air dams, further baffle sealing, etc. you can also flow match the cylinders after break in. Don't worry about the individual EGTs for now. This could be caused by probe calibration or location in the exhaust tube.
I'll watch the max CHT more closely whilst ground running.
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  #7  
Old 05-06-2014, 05:55 PM
Derek Derek is offline
 
Join Date: Jan 2011
Location: Sydney, Australia
Posts: 86
Default Thanks JD

Quote:
Originally Posted by jdeas View Post
Check the spread on leaning. Possible fuel flow to #1 is way off the other three. I had the same problem and had to return my flow divider to fix it.
Ive been told of a method to check the flow divider is to run the boost pump and capture then measure the amount of fuel being delivered at each of the injectors, this will indicate if the flow divider is functioning correctly. To me this sounds like an simple test, just wondering if anyone has done this ?
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  #8  
Old 05-06-2014, 06:08 PM
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Kahuna Kahuna is online now
 
Join Date: Dec 2004
Location: Gold Hill, NC25
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Quote:
Originally Posted by Derek View Post
Thanks for you reply, newbie question just to be sure.

Do I lean progressivly on the ground ( making sure I dont exceed 380 degrees F CHT) and then compare where No.1's CHT is to the other 3 ?
Do not be afraid of the red knob. Go fly, keep MP below 24", check to see when all 4 EGT's peak. Check the difference in the fuel flow between the first to peak and the last. Use your efis to record.
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  #9  
Old 05-07-2014, 02:14 AM
BobTurner BobTurner is offline
 
Join Date: Dec 2011
Location: Livermore, CA
Posts: 7,867
Default

Quote:
Originally Posted by Derek View Post
Ive been told of a method to check the flow divider is to run the boost pump and capture then measure the amount of fuel being delivered at each of the injectors, this will indicate if the flow divider is functioning correctly. To me this sounds like an simple test, just wondering if anyone has done this ?
This is sometimes called the coke bottle test. Loosen all tubing clamps, remove injector #1 and at least one other, direct injectors into clear containers like coke bottles. Mixture full forward, turn on electric fuel pump until easy to see fuel is collected. Compare bottles, does bottle #1 have more gas than others?
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  #10  
Old 05-07-2014, 06:41 AM
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RV10inOz RV10inOz is offline
 
Join Date: May 2008
Location: Brisbane Qld. Aust.
Posts: 2,308
Default

Derek,

You need to do a lot of things.....call me ASAP. I reckon also start booking your airline tickets to Perth for Friday the 16th of May returning Sunday night.

Check your PM's
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