[Healeys] playing detective

[Warthodson at aol.com]

I too have done dozens of leak down tests & do not find it difficult to 
locate top dead center on each cylinder. In fact is easy. Leak down testers do not 
require 150 PSI or any other specific pressure. One gage reads the pressure 
being supplied from the source. the other gage reads the pressure in the 
cylinder being tested. It is the percentage difference between the two gages that 
tells you how much "lead down" you have. For instance, if the supply is 79 PSI & 
the cylinder reads 71 PSI, the leak down is 8 PSI or 10%. 100 PSI supply 
pressure makes it easy to calculate the leak down percentage.
Gary Hodson
 
 
In a message dated 9/28/2007 9:57:32 AM Central Daylight Time, 
richard.ewald at gmail.com writes:

it is as much as an eyelash one way or the other 150 psi will push it down.  
Again ask me how I know this.  I have done dozens and dozens of leak down 
tests a professional technician.  Depending on the engine, I would use as little 
as 50 PSI to prevent such rotation. 
Next we get into the issue of just where do you get 150 PSI.  My home 
compressor wont' do that (commercial grade unit) and no shop I have worked in had 
that kind of pressure... :-)





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