Any of you guys have a suggestion on the issue I'm having?
Superior IO-360 with high compression pistons (185hp), Hartzell Blended Airfoil, Silver Hawk fuel servo(Bendix) with ram air (no filter at the moment), Slick mag on the left, Lightspeed ignition on the right. The engine has about 130 hrs on it now. The engine starts easily and generally runs fantastic on the ground and feels/sounds strong during takeoff and climb. That being said, when I power back to say 21" and 2450 RPM, the engine generally sounds good, but I detect an intermittent "miss" or hesitation. Its just enough to make me not fully trust the engine 100% and it wears on my mind. The Dynon D180 shows the engine as being perfectly healthy. All the CHT's and EGTs look great and within a few degrees of one another. Oil temp stays in the 180 degree range. When I do my engine runup, I get a big decrease in RPM if I turn off the Electronic (probably 200 or 300 rpm), so the mag seems weak. When I turn off the mag of course, there's very little drop. In flight, if I turn off the EI, the engine of course runs poorly, so it's hard to tell, but I think I still feel the intermittent miss. If I turn off the Mag, I still think I feel the miss. I've checked timing on both the Mag and EI. I've verified that the coax wires coming from the electronic ignition aren't in close proximity to the crank sensor wires. I've monitored fuel pressures. The boost pump doesn't make any difference in the "miss". To me, it seem to be related to ignition. I've pulled the prop and verified the correct location of the sensor magnets, the spacing between the sensors and flywheel magnets and I've confirmed correct orientation / timing of the flywheel to the crank sensor.
With the above in mind, whats the likelihood of having an intermittent stuck valve that's causing my problem? Do valves intermittently stick? Does a sticky valve ALWAYS show up on electronic engine monitors? I'm not seeing any power loss or anything reflected in EGT or CHT's on the Dynon. Its rock solid as far as temps. The only thing I've noticed that seems to make the "mis" either go away or become less detectible is to run higher RPM's and MP's. During takeoff, at full power and high RPM, I've never noticed the mis and it runs strong. It only seems to be a constant issue at more reasonable cruise power settings where I always want to run to conserve fuel. Mixture setting doesn't seem to affect the mis whatsoever.
Any help would be appreciated as I'm running out of ideas. I'm considering going dual electronic ignition or installing a bendix mag which I've been told produces a stronger spark than today's slick mags, but I'm just not sure the mag is my problem (even though I feel it's weak considering the amount of mag drop I'm getting). My friend has the same exact engine/mag/electronic ignition setup in his 7A (but with standard compression) and his engine runs GREAT!
Any Ideas?
Chad
Superior IO-360 with high compression pistons (185hp), Hartzell Blended Airfoil, Silver Hawk fuel servo(Bendix) with ram air (no filter at the moment), Slick mag on the left, Lightspeed ignition on the right. The engine has about 130 hrs on it now. The engine starts easily and generally runs fantastic on the ground and feels/sounds strong during takeoff and climb. That being said, when I power back to say 21" and 2450 RPM, the engine generally sounds good, but I detect an intermittent "miss" or hesitation. Its just enough to make me not fully trust the engine 100% and it wears on my mind. The Dynon D180 shows the engine as being perfectly healthy. All the CHT's and EGTs look great and within a few degrees of one another. Oil temp stays in the 180 degree range. When I do my engine runup, I get a big decrease in RPM if I turn off the Electronic (probably 200 or 300 rpm), so the mag seems weak. When I turn off the mag of course, there's very little drop. In flight, if I turn off the EI, the engine of course runs poorly, so it's hard to tell, but I think I still feel the intermittent miss. If I turn off the Mag, I still think I feel the miss. I've checked timing on both the Mag and EI. I've verified that the coax wires coming from the electronic ignition aren't in close proximity to the crank sensor wires. I've monitored fuel pressures. The boost pump doesn't make any difference in the "miss". To me, it seem to be related to ignition. I've pulled the prop and verified the correct location of the sensor magnets, the spacing between the sensors and flywheel magnets and I've confirmed correct orientation / timing of the flywheel to the crank sensor.
With the above in mind, whats the likelihood of having an intermittent stuck valve that's causing my problem? Do valves intermittently stick? Does a sticky valve ALWAYS show up on electronic engine monitors? I'm not seeing any power loss or anything reflected in EGT or CHT's on the Dynon. Its rock solid as far as temps. The only thing I've noticed that seems to make the "mis" either go away or become less detectible is to run higher RPM's and MP's. During takeoff, at full power and high RPM, I've never noticed the mis and it runs strong. It only seems to be a constant issue at more reasonable cruise power settings where I always want to run to conserve fuel. Mixture setting doesn't seem to affect the mis whatsoever.
Any help would be appreciated as I'm running out of ideas. I'm considering going dual electronic ignition or installing a bendix mag which I've been told produces a stronger spark than today's slick mags, but I'm just not sure the mag is my problem (even though I feel it's weak considering the amount of mag drop I'm getting). My friend has the same exact engine/mag/electronic ignition setup in his 7A (but with standard compression) and his engine runs GREAT!
Any Ideas?
Chad