exerpts from X Jets
Another interesting finding was that the coating of the combustion chamber by combustion products had a significant effect in reducing heat transfer. Heat transfer decreased by 20 percent in the first 15 hours of operation and leveled off after 40 hours. The coating was measured at .008 inch after 90 hours. Now you know at least one reason why new engines run hotter!! On an engine which is consistently run with a rich mixture you can expect this coating to be much thicker and for the cylinder to run relatively cooler.
If all other conditions remained the same, ignition advance from 25 to 42 degrees caused an increase in heat transfer of 11.4 % in the test engine which resulted in higher CHT's. Without an ignition advance system you can expect your engine to run cooler than mine. Conversely, if you have Electronic Ignition, you can benefit by turning the ignition advance OFF if the CHT's are getting too hot in the climb.
These are some of the comments taken from the X-Jets that were posted earlier.
Some thought I am going through on the lightspeed ignition, and waiting
on the carbon buildup in the engine.
Just went through 10 hours. Want it to be 50.
Another interesting finding was that the coating of the combustion chamber by combustion products had a significant effect in reducing heat transfer. Heat transfer decreased by 20 percent in the first 15 hours of operation and leveled off after 40 hours. The coating was measured at .008 inch after 90 hours. Now you know at least one reason why new engines run hotter!! On an engine which is consistently run with a rich mixture you can expect this coating to be much thicker and for the cylinder to run relatively cooler.
If all other conditions remained the same, ignition advance from 25 to 42 degrees caused an increase in heat transfer of 11.4 % in the test engine which resulted in higher CHT's. Without an ignition advance system you can expect your engine to run cooler than mine. Conversely, if you have Electronic Ignition, you can benefit by turning the ignition advance OFF if the CHT's are getting too hot in the climb.
These are some of the comments taken from the X-Jets that were posted earlier.
Some thought I am going through on the lightspeed ignition, and waiting
on the carbon buildup in the engine.
Just went through 10 hours. Want it to be 50.