larry@oma

what values does a porsche shop use to perform the cylinder leakdown test? on my aircooled aircraft engine. each cylinder is pressurized to 80#.and allowed to leakdown for an exact # of seconds.(can not remember how many)i think 20. at the end of this carefully measured timeframe.the cylinder pressure is noted. (typical for my engine is 72 #)the cylinder leakdown for that one cylinder is then expressed as 80/72.BUT,i keep seeing porsche leakdown tests referring to a % figure. what is the timeframe for this? and how many psi is the cylinder initially pressurized too? these two figures must be used by all who perform this test?? if not ,how can you compare one porsche leakdown test to anther porsche leakdown test?--thanks---larry--