Leak Down Test
#11
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I go out on a limb here. We make leak testers and sell a few hundred a year. For represenative numbers on the engine, as Info said, you need to leak the engines after they have reached operating temperature. This allows the metal parts to expand due to the thermal temp. With that said, now out to the limb, with the "new thinking" on ring gaps and "loose" clearances that have been experimented with successfully in motorsports, it has been a growing trend to not pay to much attention to leak numbers partly due to the fact that the test is not done in real life conditions. Kinda like sitting in a car, not driving it, and saying damn, this thing handles good. I'm not saying throw them our or don't do them, but with nice even compression numbers like these engines have, it would be my guess to venture a little carbon build up, we all know these things run rich, has to do with the leak numbers.
Chris
Chris
#12
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Chris-- You make excellent points as usual. You'd obviously expect uniform compression numbers from an engine with 14 hours. What's an acceptable Leak Down number in a recreational marine engine is certainly different then ,let's say an engine used for drag racing. My only point is that a prospective boat buyer looking at a motor with 14 hours and an LD of 26% on any cylinder should certainly understand what's driving that value before committing to the boat. Good dialogue as usual--Lou
#13
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Scott
Good work on your part to have the tests done. Now, place your wallet back in your pocket and slowly back away from the boat.
Good work on your part to have the tests done. Now, place your wallet back in your pocket and slowly back away from the boat.