Greetings,
I have a bit of a mystery and would like to appeal to the brain-trust for assistance.
The configuration: RV-7, Lycoming YIO-360-A1B6, Hartzell F7497 CS Prop, Dual Lightspeed Plasma III - timed to 20?, Denso IK27 plugs, Avstar AVX-5VA1 fuel injection servo, Standard pistons (8.7:1 CR), Custom Plenum, SW 8406R oil cooler mounted on firewall fed by 3" SCEET duct from above #4 cylinder, Temperature risers are installed in front of #1 and #2 cylinders - #1 is 1/4" lower than "stock", #2 is 3/4" lower than "stock", #2 cylinder is the hottest - followed by #3, #1 and ultimately #4.
The symptom: during climb out, and in all subsequent phases of operation at or above 80 Kias, the #4 cylinder will run ~30? colder than the other 3 cylinders (#4 max is 336?F, others max ~365?F).
Additional data: all 4 cylinders "peak" within .1GPH (e.g. 9.3GPH at 6500msl), and all EGTs are within 75?F of each other for all phases of flight. Probes have been swapped, tested, and appear correct.
My objective is to get #4 up to the same temps as the rest. Any ideas would be greatly appreciated.
B
I have a bit of a mystery and would like to appeal to the brain-trust for assistance.
The configuration: RV-7, Lycoming YIO-360-A1B6, Hartzell F7497 CS Prop, Dual Lightspeed Plasma III - timed to 20?, Denso IK27 plugs, Avstar AVX-5VA1 fuel injection servo, Standard pistons (8.7:1 CR), Custom Plenum, SW 8406R oil cooler mounted on firewall fed by 3" SCEET duct from above #4 cylinder, Temperature risers are installed in front of #1 and #2 cylinders - #1 is 1/4" lower than "stock", #2 is 3/4" lower than "stock", #2 cylinder is the hottest - followed by #3, #1 and ultimately #4.
The symptom: during climb out, and in all subsequent phases of operation at or above 80 Kias, the #4 cylinder will run ~30? colder than the other 3 cylinders (#4 max is 336?F, others max ~365?F).
Additional data: all 4 cylinders "peak" within .1GPH (e.g. 9.3GPH at 6500msl), and all EGTs are within 75?F of each other for all phases of flight. Probes have been swapped, tested, and appear correct.
My objective is to get #4 up to the same temps as the rest. Any ideas would be greatly appreciated.
B