I've got a vexing cooling imbalance issue. Engine is a Hirth F23, 2 cylinder opposed, 2 cycle, fuel injected. Thanks to the great help from this forum, I've got my engine running great, and it's time to tackle this issue.
The left cylinder runs substantially hotter than the right (say a delta of 60°F). The delta remains quite large in both cruise and climb. (Temperature accuracy and engine issues have been quite thoroughly checked)
Everything is pretty symmetric between the two sides -cowl inlets, outlets, cylinder baffle.
I've tried widening the left inlet to account for engine twisting under power so the inlet remains lined up with the baffle.
I also tried a vane in the baffling of the hot side to segregate the head from the barrel.
I also tried enlarging the inlet and baffle about 20%.
All of the above measures seem to help marginally, but no large improvement that I was hoping for.
The firewall forward is a one off of my design, so nothing the same to compare to. (Monnet Moni originally had a very underpowered KFM 107 25HP)
I'm wondering if it's due to the rotation of the propeller and the shape of the cowling that's causing the asymmetry?
Or something more basic that I'm missing? Any suggestions from someone with some formal aerodynamic background?
The left cylinder runs substantially hotter than the right (say a delta of 60°F). The delta remains quite large in both cruise and climb. (Temperature accuracy and engine issues have been quite thoroughly checked)
Everything is pretty symmetric between the two sides -cowl inlets, outlets, cylinder baffle.
I've tried widening the left inlet to account for engine twisting under power so the inlet remains lined up with the baffle.
I also tried a vane in the baffling of the hot side to segregate the head from the barrel.
I also tried enlarging the inlet and baffle about 20%.
All of the above measures seem to help marginally, but no large improvement that I was hoping for.
The firewall forward is a one off of my design, so nothing the same to compare to. (Monnet Moni originally had a very underpowered KFM 107 25HP)
I'm wondering if it's due to the rotation of the propeller and the shape of the cowling that's causing the asymmetry?
Or something more basic that I'm missing? Any suggestions from someone with some formal aerodynamic background?
