|
-
POSTING RULES

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

01-18-2020, 01:27 PM
|
|
|
|
Join Date: Jun 2018
Location: Sun City, California
Posts: 9
|
|
High EGT and CHT on #4, IO 360
I have a high reading on my #4 EGT 1500+, CHT 361, on IO 360 RV-7 at full throttle departure 2600 rpm. We have checked and changed the spark plugs and switched the sensor. We believe there are no air leaks. Have not yet checked the injectors, as the aircraft has an extended cowl. Temp remains the same.
Please help with advice for the next step.
|

01-18-2020, 01:35 PM
|
 |
|
|
Join Date: Jun 2011
Location: Indianapolis
Posts: 228
|
|
Quote:
Originally Posted by AHelliwell
I have a high reading on my #4 EGT 1500+, CHT 361, on IO 360 RV-7 at full throttle departure 2600 rpm. We have checked and changed the spark plugs and switched the sensor. We believe there are no air leaks. Have not yet checked the injectors, as the aircraft has an extended cowl. Temp remains the same.
Please help with advice for the next step.
|
If in fact there are no air leaks, making that cylinder run lean, then next step is to check the fuel line to that cylinder for an obstruction. You might flow the four lines checking for balanced flow.
__________________

Larry Anderson
Indianapolis
RV-Super 8 N88XT SOLD
RV-10 QB N38LA Flying
Helicopter Instructor Pilot
Standardization I.P.
Instrument Examiner
U.S. Army Retired
EMS Pilot for LifeLine
At IU Health Retired :-)
Although Exempt,
Donated for 2020
|

01-18-2020, 01:57 PM
|
|
|
|
Join Date: Oct 2013
Location: Schaumburg, IL
Posts: 5,298
|
|
Quote:
Originally Posted by AHelliwell
I have a high reading on my #4 EGT 1500+, CHT 361, on IO 360 RV-7 at full throttle departure 2600 rpm. We have checked and changed the spark plugs and switched the sensor. We believe there are no air leaks. Have not yet checked the injectors, as the aircraft has an extended cowl. Temp remains the same.
Please help with advice for the next step.
|
what is high power peak EGT on #4? Mixture can't make EGT go higher than typical peak EGT. Timing, however, can. When one cyl EGT goes above normal peak EGT, it usually means retarded timing, typically due to only one plug firing. CHT typically drops a bit from normal in this case. With only one plug firing, you should expect EGT at least 100* higher than normal for that power configuration.
If normal peak EGT is 1500 or above, I would be looking at a plugged injector. intake leaks typically show no symptoms at WOT / full power. They are more obvious at low MAP operations. if normal TO power normally delivers 1300 EGTs, the 1500 you are seeing could still be from one plug firing even if 1500 is below typical peak EGT. If injector isn't plugged, check the two plug wires.
Larry
__________________
N64LR - RV-6A / IO-320, Flying as of 8/2015
N11LR - RV-10, Flying as of 12/2019
Last edited by lr172 : 01-18-2020 at 02:17 PM.
|

01-18-2020, 01:58 PM
|
 |
|
|
Join Date: Jun 2005
Location: Georgetown, TX
Posts: 331
|
|
For reference sake -- 361?F is about what I see on my RV-7 with an IO-360-A1B6, stock cowl during a full power climbout @2700RPM 29"MAP, 16GPH, 15?C OAT...
2600RPM is a bit low for full power ops -- what does it do at 2700RPM?
How about your power (How many " MAP, what altitude?), what's your fuel flow and pressure?
How does #4 EGT & CHT compare to the other three cylinders?
Has it always behaved this way, or did it just start?
__________________
Brian Decker
Retired Firmware Guy and Airplane Builder
2020 RV-14 QB -- Under construction - Tailcone & Empennage Complete.
2018 RV-7 QB -- Built, Flying
2007 RV-7 QB -- Built, Drowned, Resurrected and flying
1998 RV-8 QB -- Started, Sold
1986 Mooney 205SE
1980 Mooney 231
Aided and abetted building a number of other RV's.
|

01-19-2020, 09:28 AM
|
|
|
|
Join Date: Jun 2018
Location: Sun City, California
Posts: 9
|
|
Thanks so much everyone. I believe we may have fixed the problem. Found some manifold air leaks on cylinders #2 and #3. Weird as it manifested on the instrument in the panel on #4. Looks like it brought temps back to even with all cylinders. I'm going up today to confirm.
Really appreciate all the replies to help me.
|

01-19-2020, 09:54 AM
|
 |
Senior Curmudgeon
|
|
Join Date: Sep 2005
Location: Dayton Airpark, NV A34
Posts: 15,420
|
|
Quote:
Originally Posted by AHelliwell
Found some manifold air leaks on cylinders #2 and #3. Weird as it manifested on the instrument in the panel on #4.
|
Have you checked to make sure all temp probe wiring is to the correct cylinders??
__________________
Mike Starkey
VAF 909
Rv-10, N210LM.
Flying as of 12/4/2010
Phase 1 done, 2/4/2011 
Sold after 240+ wonderful hours of flight.
"Flying the airplane is more important than radioing your plight to a person on the ground incapable of understanding or doing anything about it."
|

01-19-2020, 11:38 AM
|
|
|
|
Join Date: Oct 2013
Location: Schaumburg, IL
Posts: 5,298
|
|
Quote:
Originally Posted by AHelliwell
Thanks so much everyone. I believe we may have fixed the problem. Found some manifold air leaks on cylinders #2 and #3. Weird as it manifested on the instrument in the panel on #4. Looks like it brought temps back to even with all cylinders. I'm going up today to confirm.
Really appreciate all the replies to help me.
|
While every plane is different , 1500 is a typical peak egt. If you are still getting that at full power down low, you likely need to address something.
__________________
N64LR - RV-6A / IO-320, Flying as of 8/2015
N11LR - RV-10, Flying as of 12/2019
|

01-19-2020, 08:13 PM
|
|
|
|
Join Date: Jun 2018
Location: Sun City, California
Posts: 9
|
|
Quote:
Originally Posted by Mike S
Have you checked to make sure all temp probe wiring is to the correct cylinders??
|
Not yet, on my next day off I will keep working on it. Looks like #3 had the air leak and EGT on #4 is corrected. At least I can fly.
Thanks for your input.
|

01-19-2020, 08:19 PM
|
|
|
|
Join Date: Jun 2018
Location: Sun City, California
Posts: 9
|
|
Quote:
Originally Posted by Mike S
Have you checked to make sure all temp probe wiring is to the correct cylinders??
|
Not yet, but:
On my next day off I will keep working on it. Looks like #3 had the air leak and EGT on #4 is corrected. At least I can fly.
Thanks for your input.
|
| Thread Tools |
Search this Thread |
|
|
|
| Display Modes |
Linear Mode
|
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 09:09 AM.
|