Compression Testing

[bobden72]

Hi all I have built a Hoglet and before trying to start it I decided to use my newly constructed compression tester. When turning the engine over I get 50 psi max but it drops off to zero, is this OK or should it hold the pressure, if so for how long.

 

[Charles Lamont]

At a modest 600 rpm the compression stroke takes 1/20 second. I can't see any need to hold pressure for longer than that.

 

[tornitore45]

Aside the leak down issue, compression testing on small engine is difficult because of the added volume of the tester. Unless one rigs up some check valve contraption.

 

[deverett]

Here's a link to Jan Ridder's compression tester:
http://www.ridders.nu/Webpaginas/pagina_compressiemeter/compressiemeter_frameset.htm
And here's Brian Rupnow's compression tester:

Dave
The Emerald Isle