Flying_Monkey
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Continuing my series of posts about my annual... 
I did the savvy Induction Leak Test described as follows:
"This in-flight test is an effective method for detecting leaks in the engine’s induction system. It is best accomplished in level cruise fl ight at about 5,000 feet MSL. It consists of a pair of tests: the high-MP test and the low-MP test. For the high-MP test, start with a relatively high power setting—wide-open throttle for normally aspirated engines, or MP equal to outside ambient pressure for turbocharged engines—and full-rich mixture. Write down the EGT for each cylinder. For the low-MP test, reduce MP by about 10 inches and again write down the EGT for each cylinder. Disregard the absolute EGT values. Instead, calculate the change in EGT (“delta”) for each cylinder between the highMP and low-MP tests. Ideally, the amount of EGT change should be roughly the same for all cylinders. If one cylinder (or two adjacent cylinders) exhibit(s) signifi cantly less change than the others, suspect an induction system leak aff ecting that cylinder (or those adjacent cylinders). Here’s the principle behind this test: During the high-MP test, the induction manifold pressure is very close to outside ambient pressure, so any induction leak will have little or no eff ect on engine operation. During the low-MP test, the manifold pressure is signifi cantly lower than outside ambient (by about 10 inches), so any induction leak will cause the aff ected cylinder (or cylinders) to run substantially leaner than the others, resulting in a smaller drop in EGT than the others."
According to the flight test profile, any cylinder with an induction leak would be LEANER than the others which would usually manifest in higher EGT (the test starts full rich). I'm not sure I understand that logic but if we go by this then I should see any anomalous cylinder be leaner with a higher EGT. It looks like my #2 cylinder (ORANGE LINE) exhibits less of a change than all the others. The others EGT rise more than #2...which would indicate they are all leaner than #2. So, do I have an induction leak in all cylinders besides #2 or an induction leak in #2 or no induction leak at all? Any help is greatly appreciated. (I did the test at 2 different altitudes and FULL throttle MAP settings and both at full rich)
Here is the link to the interactive flight data:
https://apps.savvyaviation.com/flights/4296146/0150676a-4f98-4550-ba9a-8aa9487317fa
-Eric
I did the savvy Induction Leak Test described as follows:
"This in-flight test is an effective method for detecting leaks in the engine’s induction system. It is best accomplished in level cruise fl ight at about 5,000 feet MSL. It consists of a pair of tests: the high-MP test and the low-MP test. For the high-MP test, start with a relatively high power setting—wide-open throttle for normally aspirated engines, or MP equal to outside ambient pressure for turbocharged engines—and full-rich mixture. Write down the EGT for each cylinder. For the low-MP test, reduce MP by about 10 inches and again write down the EGT for each cylinder. Disregard the absolute EGT values. Instead, calculate the change in EGT (“delta”) for each cylinder between the highMP and low-MP tests. Ideally, the amount of EGT change should be roughly the same for all cylinders. If one cylinder (or two adjacent cylinders) exhibit(s) signifi cantly less change than the others, suspect an induction system leak aff ecting that cylinder (or those adjacent cylinders). Here’s the principle behind this test: During the high-MP test, the induction manifold pressure is very close to outside ambient pressure, so any induction leak will have little or no eff ect on engine operation. During the low-MP test, the manifold pressure is signifi cantly lower than outside ambient (by about 10 inches), so any induction leak will cause the aff ected cylinder (or cylinders) to run substantially leaner than the others, resulting in a smaller drop in EGT than the others."
According to the flight test profile, any cylinder with an induction leak would be LEANER than the others which would usually manifest in higher EGT (the test starts full rich). I'm not sure I understand that logic but if we go by this then I should see any anomalous cylinder be leaner with a higher EGT. It looks like my #2 cylinder (ORANGE LINE) exhibits less of a change than all the others. The others EGT rise more than #2...which would indicate they are all leaner than #2. So, do I have an induction leak in all cylinders besides #2 or an induction leak in #2 or no induction leak at all? Any help is greatly appreciated. (I did the test at 2 different altitudes and FULL throttle MAP settings and both at full rich)
Here is the link to the interactive flight data:
https://apps.savvyaviation.com/flights/4296146/0150676a-4f98-4550-ba9a-8aa9487317fa
-Eric
