RE: MOKI RADIAL Care and Maintenence
Waxman, Kochj,
I'm the guy who wrapped the exhaust ring on page 35. I am going to buy two more radials this season and plan to have the exhaust rings ceramic coated (inside & out). The glass wrap that I used from J.C. Whitney lowered the incowl temperature about 40-45 deg. F., which was enough to keep the operating CHT temperatures to about 230 or lower. It also made wonderful smoke. I estimate that it raised the exhaust ring temperature about 100 deg F. I can't honestly say that I recognized any significant improvement in performance. I was just happy to improve the CHT.
I use an Eagle Tree onboard data system to monitor operating temperatures on at least two cylinders. Eagle Tree has the hardware to monitor the EGT, but I haven't incorporated it.
Incorporating baffles between the cylinders will improve cylinder head airflow, but significantly reduce the airflow across the exhaust ring. Without additional thermal protection, the exhaust ring radient heating rises dramatically. I have heard people comment that they have experience temperatures high enough to make the ring glow. By using additional thermal insulation, either ceramic and/or glass wrap, the cylinder baffling can be used without excessive incowl temerature increases.
I plan to baffle my 250 and start collecting some flight data as soon as the weather cooperates. I am targeting my CHT at between 185 to 210 deg. F for all five cylinders. If the coolest cylinder (#3 counterclockwise) gets below 185 deg. F it will start to drop out and foul.
Opinions are worth about what you pay for them, but hard data can be quite valuable. I am constantly amazed that people spend large sums of money for these engines and don't spend less then $200 for real time inflight engine data. I have all my large engines instrumented and use the data to accurately tune the engines. There is a significant difference between static and inflight data. I constantly hear people say "My engine runs great!!" and I ususally say "Oh really, how do you know?".
I would also highly recommend an APS fuel pump. The onboard pulse system (tube from forward air pump to carb) is very vulnerable to dirt or grease. If there is any interruption of the pulse, the engine immediately goes lean and the operating temperatures begin to rise. The turbulator has reported improvements in cylinder performance uniformity, but I have no first hand experience. The turbulator mounts between the carb and the engine case.
Good luck,