Mazda Rotary Club

General => General Technical => Anything Engine/Performance/Tuning related => Topic started by: ferruh on February 08, 2007, 04:15:30 PM

Title: !! Compression test - whats it all \'bout ??
Post by: ferruh on February 08, 2007, 04:15:30 PM
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..
Title: !! Compression test - whats it all \'bout ??
Post by: G@NDY on February 08, 2007, 04:22:28 PM
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.
Title: !! Compression test - whats it all \'bout ??
Post by: Warthog on February 08, 2007, 04:24:08 PM
Nice reply ^^^^^^^^:Typing
Title: !! Compression test - whats it all \'bout ??
Post by: ferruh on February 09, 2007, 02:18:55 AM
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
Title: !! Compression test - whats it all \'bout ??
Post by: John Yorke on February 09, 2007, 07:13:08 PM
Just make sure a rotary compression tester is used.