LOP

[deadbug]

Greg, Cruiser,

Thanks for your thoughts.  I have flown behind these stock injectors for over 1500 hours and in spite of a brand new overhaul 130 hours (13 months) ago, it acts the same way lean of peak.  I have been told it is very common with the Lyc IO-360s using stock injectors.
I typically cruise at 7-9000 feet, at approximately 65% power 50-80 ROP and get fuel flow and performance right at book value (interpolating between best pwr/best econ).  Just the other day I happenned to record the following EGT/CHT readings:

7000' MSL, OAT: +18C, MP/RPM= 22.9/2400, 60ROP,.....64% power according to the charts
      EGT/CHT
#1  1351/378
#2  1289/362
#3  1338/374
#4  1294/356

What made me think about GAMIs was to equalize the "left bank" (2 & 4) cylinders to the "right" bank (1 & 3); as 1/3 are balanced and 2/4 are also balanced--but the left bank is definitely higher than the right.  I thought the GAMIs would maybe help balance this out and as a side bonus, make LOP possible.
Oh, BTW, was the GAMI tweaking difficult?  My fuel flow indicator is a Hoskins 101 (old) and in spite of a new transducer, seems to indicate 1 GPH higher than actual.

[Cruiser]

Quote: deadbug

Greg, Cruiser,

Thanks for your thoughts.  I have flown behind these stock injectors for over 1500 hours and in spite of a brand new overhaul 130 hours (13 months) ago, it acts the same way lean of peak.  I have been told it is very common with the Lyc IO-360s using stock injectors.

I typically cruise at 7-9000 feet, at approximately 65% power 50-80 ROP and get fuel flow and performance right at book value (interpolating between best pwr/best econ).  Just the other day I happenned to record the following EGT/CHT readings:

7000' MSL, OAT: +18C, MP/RPM= 22.9/2400, 60ROP,.....64% power according to the charts

      EGT/CHT

#1  1351/378

#2  1289/362

#3  1338/374

#4  1294/356

What made me think about GAMIs was to equalize the "left bank" (2 & 4) cylinders to the "right" bank (1 & 3); as 1/3 are balanced and 2/4 are also balanced--but the left bank is definitely higher than the right.  I thought the GAMIs would maybe help balance this out and as a side bonus, make LOP possible.

Oh, BTW, was the GAMI tweaking difficult?  My fuel flow indicator is a Hoskins 101 (old) and in spite of a new transducer, seems to indicate 1 GPH higher than actual.

[TurboExec]

You can try to switch the injectors around.  Move injector 1 (the highest EGT) to #2 (the lowest).  Move #3 to #4.  That may even out the balence more....or it may make it worse.   But it is worth a try first before throwing out the money for the GAMIs.

For what it is worth you are one of the few I know that can't go LOP with stock injectors.  Which model IO-360 is that? A1A?

Quote: deadbug

Greg, Cruiser,

Thanks for your thoughts.  I have flown behind these stock injectors for over 1500 hours and in spite of a brand new overhaul 130 hours (13 months) ago, it acts the same way lean of peak.  I have been told it is very common with the Lyc IO-360s using stock injectors.

I typically cruise at 7-9000 feet, at approximately 65% power 50-80 ROP and get fuel flow and performance right at book value (interpolating between best pwr/best econ).  Just the other day I happenned to record the following EGT/CHT readings:

7000' MSL, OAT: +18C, MP/RPM= 22.9/2400, 60ROP,.....64% power according to the charts

      EGT/CHT

#1  1351/378

#2  1289/362

#3  1338/374

#4  1294/356

What made me think about GAMIs was to equalize the "left bank" (2 & 4) cylinders to the "right" bank (1 & 3); as 1/3 are balanced and 2/4 are also balanced--but the left bank is definitely higher than the right.  I thought the GAMIs would maybe help balance this out and as a side bonus, make LOP possible.

Oh, BTW, was the GAMI tweaking difficult?  My fuel flow indicator is a Hoskins 101 (old) and in spite of a new transducer, seems to indicate 1 GPH higher than actual.

[Greg_D]

Bill, don't worry....there are many folks who can't run LOP with stock injectors. In fact, some Lycoming 540s can't seem to run LOP even with Gamis.  There are some turbocharged Continental 360s that have problems as well.

The raw EGT numbers aren't going to do you much good.  Go to Gami's web site and download the form and instructions to do a Gami lean test.  This will determine the fuel flow difference between the 1st and last cylinder to peak. Tweaking the setup just involves removing and replacing injectors after you consult with the folks at Gami.  They are very easy to work with and know this stuff well.  They got it right the 3rd time on my M20F.  In fact, the engine was so smooth, it would cut off as I leaned it while LOP before I got any vibration at all.

[deadbug]

Thanks for all the info guys...