planenutz
Well Known Member
Hey Team. A question for the electronic ignition experts if you have time, please:
I completed the installation of a SUREFLY SIM4P during the 100 hour/Annual and flew for the first time today. The IO-360 has been running so sweetly with a SIM4N on the right side so I decided to fit a 4P to the left side and set them up for variable timing. I was hoping to achieve a couple of goals - better starting, improved leaning and the possibility of slightly reduced fuel flows. I wasn't expecting too much in the way of reduced fuel flows as I've been enjoying pretty good consumption up to now but I thought it might be slightly better. Reading what I have on EIS I was expecting a slight increase in CHT's... maybe a few degrees, especially as the engine now has variable timing.
During the two flights I made today the CHT's appeared to be lower than they used to be by about 5 or 6 degrees C - around 40 deg F. I wasn't able to quantify any change in fuel consumption as the weather made that a little difficult but I feel I might be seeing a small reduction. Am I to assume that this perceived reduction in fuel consumption is directly responsible for the reduction in CHT? Is it as simple as less fuel = less heat?
My #4 cylinder is typically the coolest, #3 the hottest and my spread has typically been around 8 to 10 deg C max (46 - 50 degF) since day one. Today #1 was coolest and if it stays that way I'm probably going to have to increase the size of the baffle up front.
Interested to understand more.
I completed the installation of a SUREFLY SIM4P during the 100 hour/Annual and flew for the first time today. The IO-360 has been running so sweetly with a SIM4N on the right side so I decided to fit a 4P to the left side and set them up for variable timing. I was hoping to achieve a couple of goals - better starting, improved leaning and the possibility of slightly reduced fuel flows. I wasn't expecting too much in the way of reduced fuel flows as I've been enjoying pretty good consumption up to now but I thought it might be slightly better. Reading what I have on EIS I was expecting a slight increase in CHT's... maybe a few degrees, especially as the engine now has variable timing.
During the two flights I made today the CHT's appeared to be lower than they used to be by about 5 or 6 degrees C - around 40 deg F. I wasn't able to quantify any change in fuel consumption as the weather made that a little difficult but I feel I might be seeing a small reduction. Am I to assume that this perceived reduction in fuel consumption is directly responsible for the reduction in CHT? Is it as simple as less fuel = less heat?
My #4 cylinder is typically the coolest, #3 the hottest and my spread has typically been around 8 to 10 deg C max (46 - 50 degF) since day one. Today #1 was coolest and if it stays that way I'm probably going to have to increase the size of the baffle up front.
Interested to understand more.
