Cossie Compression Test
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PassionFord Post Whore!!
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From: Sunderland
Cossie Compression Test
What should I be seeing when I do a compression test on my Cossie? Its a 4x4 engine. Im unsure what compression ratio is and what I should be seeing.
What reading would I see on an engine that was standard comp, 7.5:1, 7.2:1?
Thanks peoples.
What reading would I see on an engine that was standard comp, 7.5:1, 7.2:1?
Thanks peoples.
Depending on the state of the engine anything around 160-180psi is quite common, look more so for even readings across all 4 rather than just compression.
Compression and comp. ratio are two different aspects so fiding a correlation between to 2 might not be possible....especially from 7.2/7.5, its not a massive void really. The cams(worn/new?) and cam timing will also have an effect on compression.
Compression and comp. ratio are two different aspects so fiding a correlation between to 2 might not be possible....especially from 7.2/7.5, its not a massive void really. The cams(worn/new?) and cam timing will also have an effect on compression.
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PassionFord Post Whore!!
Joined: Nov 2006
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From: Sunderland
I know that comp and comp ratio are different, I was wondering if there was a correlation between the 2.
Im hoping for an interesting read from this or someone who knows for definate, not just from hearsay, to come along and say yes/no and this is why.
Just a nice informative thread for a change, no bitching and fighting would be good.
Im hoping for an interesting read from this or someone who knows for definate, not just from hearsay, to come along and say yes/no and this is why.
Just a nice informative thread for a change, no bitching and fighting would be good.
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PassionFord Post Whore!!
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From: Sunderland
Cool, I was shittin it when I did the test cos I bought the car with a suspected head gasket failure. But found a split coolant hose and that seemed to sort it. The compression test was for my piece of mind really.
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PassionFord Post Whore!!
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From: Sunderland
Sweet, thats what I hoped for. I wasnt sure what to expect.
I have been told elsewher that around 125psi is normal on a cossie???
I have been told elsewher that around 125psi is normal on a cossie???
8.5 bar at cranking speed, plugs out open throttle
Thats what the bible quotes mate for std
compression pressure at starter speed 8.5 bar comp ratio 8:1 (std)
Thats what the bible quotes mate for std
compression pressure at starter speed 8.5 bar comp ratio 8:1 (std)
Too many things effect it, not least of which is the inaccuracy of the gauges, ive seen 20psi difference between 2 gunson gauges I tested out of curiousity.
Also cam timing can have a massive effect on the compression figures you see.
155 on all 4 sounds fine to me, I wouldnt be concerned at all by that.
Also cam timing can have a massive effect on the compression figures you see.
155 on all 4 sounds fine to me, I wouldnt be concerned at all by that.
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