![]() |
Did any attend Mike Busch's "Leaning the Right Way" forum?
I attended the Tuesday session and like all his talks it was very interesting and informative. Later that day, it occurred to me that throughout his talk, during which he described how most any aircraft can run LOP, he never once mentioned that it was necessary to have a "GAMI spread" of some value (or less).
I had attended another talk at a previous Airventure, at which I recall Mike describing the importance of establishing a flow balance between each cylinder. It seemed odd that no mention was made of this during this session on how to lean. Can anyone shed any light on whether this may have been an oversight, or perhaps it is only nice to do, but not required? |
I would assume not mentioning GAMI spread was just the way the discussion went - not some new insight.
On the RV-10 (stock Van?s IO-540-D4A5) the GAMI spread started out well over a gallon per hour on the first LOP test. The engine was simply not happy as reflected in it running very rough. It took just three runs to identify which injector nozzles needed to be replaced and by what value. Four nozzles swapped out ($26 each from Air Flow Performance) and GAMI spread is consistently 0.1 gph. LOP operations are now smooth, even further into LOP than is practical. I consider tuning injector nozzles to get GAMI spread below 0.3 gph a hard requirement for any RV. Why abuse your engine when it is so easy to do this? Carl |
I was lucky. Did GAMI spread testing to see if I could improve over factory nozzles, but spread was right around 0.5 gph. Close enough for me.
|
I attended that forum & he did mention the GAMI spread.
There was a pilot with a IO-550 waiting to get his GAMI injectors and was concerned on the timing of his cylinders peaking. Mike said the whole idea with the spread is to manage the fuel flow & close the timing gap of the cylinder achieving their peak. If I understood it correctly. |
Quote:
This morning I went for a flight and ran LOP for the first time. It seemed to work well enough and significantly reduced my fuel flow. I did, however, find that the number one cylinder was running much cooler than the hottest, so I may need to do some further balancing. My issue now is that my cylinders are running too cool. This morning, they only reached ~280F when running LOP. Typically, they are about 320F. I will experiment with running a bit less lean. |
Quote:
Larry |
Quote:
|
49clipper
My cylinders run much cooler than 300f a lot. According to Lycoming, I am lucky and they said my cylinders should last til TBO. He said, call me when they get below 175f and we'll talk. Cool cylinders are a plus not a problem.
Jim |
In his book, and on my Savvy reports, Mike says a .5 spread is the acceptable GAMI spread limit for smooth LOP operations.
|
Quote:
Larry |
| All times are GMT -6. The time now is 09:13 AM. |