G
Geoff
I flew my RV-8 for the first time today. Actually, I did two very short flights. Yea! Everything went great except one of my cylinders (#4) isn't doing what it's supposed to.
I'm really glad my VM-1000C stores data at 6-second intervals. Here's what happened on the second flight. Results were similar (almost identical, in fact) for both flights, except the #4 CHT got a little hotter on the first flight because I waited longer (higher altitude) to make the initial power reduction.
During the run-up (1800 RPM), EGT #4 was about 70F higher than the rest of them. Runup EGTs (in numerical order) were 1240, 1246, 1238, and 1312.
During and just after takeoff (at 2700 RPM, 29.1" Hg.), EGT #4 climbed to almost 300F higher than the other 3 cylinders. Initial climb EGTs (in numerical order) were 1272, 1264, 1276, 1558.
After engine power reduction (to 2400 RPM, 24" Hg.), EGT #4 started to decrease immediately. However, it remained higher than the other three until approach for landing four minutes later. Just before the power reduction for final approach, EGT #4 was about 130F higher than the rest of them. In numerical order, we have 1178, 1206, 1204, 1412.
Now let's talk about CHTs. #4 is definitely the hottest, #1 is the coolest, and #2 and #3 are about equal. #4 peaked two minutes after the initial power reduction. At that point, the CHTs (in numerical order) were 350, 376, 382, 420.
So it appears that at high power settings, I have high EGT and high CHT on #4. The Sky Ranch Engineering Manual seems to suggest a partially plugged fuel injector nozzle or an induction leak on that cylinder. The engine idles fine and the mag check is fine. It also shuts down normally. All other engine parameters are normal.
Where should I start? Induction or injector nozzle? How would I go about finding an induction leak if there were one?
Thanks.
-Geoff
RV-8
Mattituck TMX-IO360 (vertical induction) with two P-mags.
I'm really glad my VM-1000C stores data at 6-second intervals. Here's what happened on the second flight. Results were similar (almost identical, in fact) for both flights, except the #4 CHT got a little hotter on the first flight because I waited longer (higher altitude) to make the initial power reduction.
During the run-up (1800 RPM), EGT #4 was about 70F higher than the rest of them. Runup EGTs (in numerical order) were 1240, 1246, 1238, and 1312.
During and just after takeoff (at 2700 RPM, 29.1" Hg.), EGT #4 climbed to almost 300F higher than the other 3 cylinders. Initial climb EGTs (in numerical order) were 1272, 1264, 1276, 1558.
After engine power reduction (to 2400 RPM, 24" Hg.), EGT #4 started to decrease immediately. However, it remained higher than the other three until approach for landing four minutes later. Just before the power reduction for final approach, EGT #4 was about 130F higher than the rest of them. In numerical order, we have 1178, 1206, 1204, 1412.
Now let's talk about CHTs. #4 is definitely the hottest, #1 is the coolest, and #2 and #3 are about equal. #4 peaked two minutes after the initial power reduction. At that point, the CHTs (in numerical order) were 350, 376, 382, 420.
So it appears that at high power settings, I have high EGT and high CHT on #4. The Sky Ranch Engineering Manual seems to suggest a partially plugged fuel injector nozzle or an induction leak on that cylinder. The engine idles fine and the mag check is fine. It also shuts down normally. All other engine parameters are normal.
Where should I start? Induction or injector nozzle? How would I go about finding an induction leak if there were one?
Thanks.
-Geoff
RV-8
Mattituck TMX-IO360 (vertical induction) with two P-mags.