dbaflyer
Well Known Member
In the spring/summer of 2020 I spent a lot of time sealing up baffles and had some positive results. This is from a flight 7/12/2020 outside air 25C. FF at take off showing 14-15 gal/hr. CHT peaked around 415 but curve was pretty flat
A year later and my #4 cylinder is really getting hotter (reaching 430 quickly) as you can see by the graph. Outside air a bit warmer at 28C. FF at take off was only showing about 12-12.5 or about 1-2 gal/hr less than a year ago.
I have checked the fuel inlet screen and it was clean. I'm not sure what might be causing this reduced FF and rapid increase in CHT on #4. I'm sure you'll want more information and will provide it as I can
This is an O-320 carb with one slick mag (left) and one EFII (right). The manifold pressure is being supplied by a port on cylinder 4. The prop is a 3 blade Catto. Max speed to date was 162KTS TAS, 2750RPM, 73% pwr, 8700 DALT
I have an oil cooler shutter that is closed on take-off and opened up as Oil temps get hotter. I've also tried to tape off a hole in the back baffling of #4 used to pipe air to the magneto.
Link to a zip file containing the two flight logs.
https://drive.google.com/file/d/15O3vHw4NCMBlvPBY2xLp4cpukfJsDSa-/view?usp=sharing
A year later and my #4 cylinder is really getting hotter (reaching 430 quickly) as you can see by the graph. Outside air a bit warmer at 28C. FF at take off was only showing about 12-12.5 or about 1-2 gal/hr less than a year ago.
I have checked the fuel inlet screen and it was clean. I'm not sure what might be causing this reduced FF and rapid increase in CHT on #4. I'm sure you'll want more information and will provide it as I can
This is an O-320 carb with one slick mag (left) and one EFII (right). The manifold pressure is being supplied by a port on cylinder 4. The prop is a 3 blade Catto. Max speed to date was 162KTS TAS, 2750RPM, 73% pwr, 8700 DALT
I have an oil cooler shutter that is closed on take-off and opened up as Oil temps get hotter. I've also tried to tape off a hole in the back baffling of #4 used to pipe air to the magneto.
Link to a zip file containing the two flight logs.
https://drive.google.com/file/d/15O3vHw4NCMBlvPBY2xLp4cpukfJsDSa-/view?usp=sharing