| As I said before, a true leakdown, or cylinder leakage tester as it’s also known, should have an orifice in it. It measures pressure drop using that orifice. Due to conservation of mass, the flow rate across the orifice will be the same as the flow rate through the leakage path(s) through the engine being tested. You measure the pressure drop across the orifice to measure the flow rate of leakage through the engine. From Wikipedia: “A leak-down tester is essentially a miniature flow meter similar in concept to an air flow bench. The measuring element is the restriction orifice and the leakage in the engine is compared to the flow of this orifice. There will be a pressure drop across the orifice and another across whatever leaks in the engine. Since the flow is the same across both, the pressure drops will also be equal if the size of the unknown leak is the same as the known orifice” I take exception to their statement that up to 20% leakage is acceptable. Perhaps in a very large engine operating in a low state of tune, but losing 20% of your intake charge before accounting for the loss of compression ratio hardly seems “acceptable” to me, especially in a high performance application. Here is a link to a DIY leakdown tester incorporating an orifice. If you insist on being a prick again, I won’t waste my time replying to you, as I didn’t before. Not trying to be antagonistic, just making a statement.
Mike ------------------------------------------------------
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