compression test figures
#1
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compression test figures
Hi can anyone tell me wot sort of compression test figures i should be getting from a standard impreza sti version 5 engine with 61k on it? Are the figures lower on the turbo side of the engine, cylinders 1n3? Cheers Steve.
#2
Ecu Specialist
Compression with the throttle fully open and all plugs removed cranking at 200-300 rpm.
std 146 to 175 psi (10.1-12.3 bar)
wear limit (worst ... 138 psi (9.7 bar)
this is the important bit ... difference between all 4 cylinders 7 psi (0.5bar) max.
so whatever level they are at the differential applies.
so no cylinders 1 and 3 "should not" be lower in that sense.
the wide range reflects the compression ratio tolerance of 7.8-8.2 to 1
bob
std 146 to 175 psi (10.1-12.3 bar)
wear limit (worst ... 138 psi (9.7 bar)
this is the important bit ... difference between all 4 cylinders 7 psi (0.5bar) max.
so whatever level they are at the differential applies.
so no cylinders 1 and 3 "should not" be lower in that sense.
the wide range reflects the compression ratio tolerance of 7.8-8.2 to 1
bob
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