|
-
POSTING RULES

-
Donate yearly (please).
-
Advertise in here!
-
Today's Posts
|
Insert Pics
|

05-06-2014, 02:40 PM
|
|
|
|
Join Date: Jan 2011
Location: Sydney, Australia
Posts: 86
|
|
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 ?

|

05-06-2014, 03:20 PM
|
 |
|
|
Join Date: Sep 2009
Location: St. Louis, MO
Posts: 1,785
|
|
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.
__________________
Bill Peyton
RV-10 - 1125 hrs
N37CP
First Flight Oct 2012
Aviation Partners, LLC
|

05-06-2014, 03:41 PM
|
 |
|
|
Join Date: Dec 2004
Location: Gold Hill, NC25
Posts: 2,398
|
|
Given the fouling, its possible that your #1 is excessively rich. When does it peak compared to the others when leaning?
|

05-06-2014, 03:52 PM
|
 |
|
|
Join Date: Mar 2006
Location: SoCal
Posts: 626
|
|
Flow problems
Quote:
Originally Posted by Kahuna
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.
__________________
JD
----------------------
RV-7 N314SY (KWHP)
IO-360-B1B
CANbus based trim/flaps and electrical
|

05-06-2014, 04:33 PM
|
|
|
|
Join Date: Jan 2011
Location: Sydney, Australia
Posts: 86
|
|
Is this the process ?
Quote:
Originally Posted by Kahuna
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 ?
|

05-06-2014, 04:36 PM
|
|
|
|
Join Date: Jan 2011
Location: Sydney, Australia
Posts: 86
|
|
Thanks Bill
Quote:
Originally Posted by Bill.Peyton
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.
|

05-06-2014, 04:55 PM
|
|
|
|
Join Date: Jan 2011
Location: Sydney, Australia
Posts: 86
|
|
Thanks JD
Quote:
Originally Posted by jdeas
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 ?
|

05-06-2014, 05:08 PM
|
 |
|
|
Join Date: Dec 2004
Location: Gold Hill, NC25
Posts: 2,398
|
|
Quote:
Originally Posted by Derek
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.
|

05-07-2014, 01:14 AM
|
|
|
|
Join Date: Dec 2011
Location: Livermore, CA
Posts: 6,767
|
|
Quote:
Originally Posted by Derek
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?
|

05-07-2014, 05:41 AM
|
 |
|
|
Join Date: May 2008
Location: Brisbane Qld. Aust.
Posts: 2,271
|
|
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
__________________
______________________________
David Brown
DYNON Authorised Dealer and Installer
The two best investments you can make, by any financial test, an EMS and APS!
|
Posting Rules
|
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts
HTML code is Off
|
|
|
All times are GMT -6. The time now is 04:00 PM.
|