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low compression

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Old 20-11-2004, 04:16 PM
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B13 JUS
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Default low compression

i have recently bought a escort cosworth, i was told it had low compression pistons but there was no reciepts. i have decide 2 take a look and take the head off. how can i tell ??????

cheeRS
Old 20-11-2004, 09:04 PM
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You need to compare the height of the piston in the bore at TDC to another standard car. In theory if its low comp then the piston crown should be lower in the bore at TDC.

Of you could remove the pistons and measure the compression height.
Old 21-11-2004, 11:30 AM
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swerv
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tbh if you know what a standard piston looks like you can tell if its been machined but you wont know the compression ratio just by looking , usually if its got valve cut outs it means its low comp, also measure the head as the pistons may have been machined to compensate for an overskimmed head hence they are not low comp unless you put a standard head on

are you taking the head off just to have a look??

what was the compression meant to be?
Old 21-11-2004, 05:43 PM
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i'm taking the head off 2 get it ported and polished, plus if the pistons are'nt low comp, i'll be doing that as well. the pistons are flush with the block at tdc and they don't have valve cut outs.
Old 21-11-2004, 05:44 PM
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pictures??
Old 28-11-2004, 03:02 PM
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pics of his pistons....





[/img]http://images8.fotki.com/v132/photos/4/41965/1564593/escortblockpistons015-vi.jpg[img][/img]
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