seamie1000

I've just checked the compression on a 4 x 4 cosworth engine that i've just bought and its reading 170 on all 4 cylinders. Is this high? On other forms i've read it says between 140 - 150 on all cylinders. Will this have any effects on my engine?

boost mad

iTrader: (8)

Ive been told the compression would vary dramaticly depending on engine spec, but never the less, that does seem alittle high

stevieturbo

Do a test on another engine.

Wouldnt be the first time a gauge hasnt been correct. Or a test procedure issue.

But the fact they are all the same is a good starting point.

Moonstone Steve.

iTrader: (2)

I did a test on mine a while ago and they all read 85psi.....lowwwwwwwwww comp or what.

Steve

St3V3_C

I thought the only thing you could gain from this kind of test was that all 4 were similar. The actual value didn't really mean anything.

boost mad

iTrader: (8)

How lower comp and what cams Steve ?

stevieturbo

If the test is done right, with an accurate gauge then it will bare some relation to compression ratio

Although obviously big cams with a lot of overlap can influence readings, likewise cams that barely opened at all could.

If it was excessively high then there could be a problem, likewise if it was 85psi as above then clearly there is a problem.


http://www.pumaracing.co.uk/comp.htm

Moonstone Steve.

iTrader: (2)

Not sure on how low comp it is m8, bd14 inlet and std exhaust

Steve

boost mad

iTrader: (8)

Karl @ NMS said i should see 100-110 on a 7.2:1 ( ish )with a BD16 inlet and std exhaust