!! Compression test - whats it all \'bout ??

[ferruh]

Can someone please tell me what does a "Compression Test" show on a rotary engine???
 
What are those 4, 5, 6, 7 and 8 bar numbers that apparently come out the test mean???
 
Should I get it done, is it worth the trip to the far far away rotary specialists outside london?
 
Thanks..

[G@NDY]

Yes mate its well worth a trip as rebuilds are often around the 3 to 4 grand mark.
A test will show the compression of the housings and rotors in bar. The higher the number the better the compression, meaning the rotor tips have a good seal (the tips wear over time, if it has a poor seal as the rotor spins round it cannot compress the gas in the chamber and therefore no combustion). The higher the compression the more combustion leading to a stronger engine. A good figure on a rebuilt engine is around 7 bar. You start getting into the realms of poor cold and hot starting with engines that have readings below 5 bar. Hope that helps.

[Warthog]

Nice reply ^^^^^^^^:Typing

[ferruh]

thanks mate. that was really useful, now i know that i have to go there! hopefully the results will be like you said around 7 bar.
 
thanks

[John Yorke]

Just make sure a rotary compression tester is used.