How long should a cylinder stay compressed?
At TDC maximum compression with the engine off, how long should the air stay pressurized in a good running engine before escaping? I can hear the air coming out in about a second or so.
At TDC maximum compression with the engine off, how long should the air stay pressurized in a good running engine before escaping? I can hear the air coming out in about a second or so.
Dan
At TDC the compressed volume is very small and it won't hold pressure very long at all. The valves should seal almost perfectly - listen in the intake and exhaust to check, but it's impossible for the rings to seal completely. The time will depend on engine size and it's compression ratio, a second or so may be perfectly normal. Like a compression test I would think it's more important to worry about uniformity across all cylinders if you're using this as some kind of test.
Anonymous
A cylinder should stay compressed for approximately 1 minute 37 seconds
Rose
about 20 minutes okay okay