Thomas Lukasczyk
Member
Hi all
I did the Exhaust-Valve wobble test (Lycoming SB388c) yesterday and all clearances turned out to be within the specified numbers.
However, both rear-cylinders almost reached the maximum allowable clearance at a reading of 0.025 and 0.028. According to the paperwork, this engine has
only 400 hours on the meter. Are these values plausible for a "low" time engine or do they necessarily indicate a "high-time" engine? How does the valve-guide wear over time?
Is it just getting worse as your hours build up or does most of the wear occur during break-in?
Obviously there is a minimum clearance to determine carbon build up. So what would be the wobble-test reading on a brandnew cylinder?
Thank you very much for your experience
regards
Thomas, RV-4
http://www.rv-4.de/
I did the Exhaust-Valve wobble test (Lycoming SB388c) yesterday and all clearances turned out to be within the specified numbers.
However, both rear-cylinders almost reached the maximum allowable clearance at a reading of 0.025 and 0.028. According to the paperwork, this engine has
only 400 hours on the meter. Are these values plausible for a "low" time engine or do they necessarily indicate a "high-time" engine? How does the valve-guide wear over time?
Is it just getting worse as your hours build up or does most of the wear occur during break-in?
Obviously there is a minimum clearance to determine carbon build up. So what would be the wobble-test reading on a brandnew cylinder?
Thank you very much for your experience
regards
Thomas, RV-4
http://www.rv-4.de/