What should the comperession be?

[Gary C]

My car went in for a compression test today, i haven\'t got it back yet but was woundering what should the compression be?

What presure is concidered "re-build time"? and what compression is safe?

just so when i go and get it and he starts telling me i dont look completly stupid lol

cheers gary

[Looney]

Cold Cranking pressure testing:
 
With test valve installed: 120 or more is good.
Without Test valve installed: 100psi bouncing. A non rhythmic bounce shows a failed seal.
 
The way the seals are spring loaded, will suggest that you do not get much time between a failing seal and complete failure. If in doubt check it out.

[John Yorke]

I hope who ever is testing it uses a propper rotary compression tester and good readings would be high 7\'s low 8\'s anything below 6 and thats not good [readings are in bar by the way:) ]

[RedRummy]

I reckon anything below 6 would mean rebuild time, but people opinions on this differ.

Strong figures would be above 7... recently rebuilt would be late 7\'s

Its important to get the figure for each rotor face on each rotor... and the figures should be within 0.1 or 0.2 of each other on each rotor face...

for example...  7.0, 7.1, 6.9 front rotor 6.8, 6.9, 7.0 rear rotor.

its important that the figures are consistent across each rotor face.

[d6277n]

A lot of cars I\'ve seen have had compression readings lower on the rear rotor... Is there any reason for this, or am I just seeing things?

Ta,

Chris.

[m4drx]

tis hotter mate