Alpine Fastback

fast freddie · Post by **fast freddie** » Thu Feb 27, 2014 2:52 pm

Hi everyone,
Please forgive the newbie, but I have an Alpine fastback and I`ve just done a compression check on all four cylinders, and been amazed that they all were between 50psi and 65psi!! The engine pulls ok and there is no lack of power, but these figures seem really low! Any ideas? or are these figures acceptable ?

pmarshal · Post by **pmarshal** » Sun Mar 02, 2014 2:18 pm

According to my Rootes Light Car Range workshop manual (which covers all 1725 engines) the compression pressure for the Alpine should be 175/185 lbs in2 (12.3/13 kg cm2). So yours does seem very low, if you're measuring correctly.

fast freddie · Post by **fast freddie** » Tue Mar 04, 2014 8:44 am

Thanks for the reply, I was unsure if the low compression engines would fall within that range, maybe I should recheck the readings and then my gauge!!

rhythmrider · Post by **rhythmrider** » Wed Mar 05, 2014 8:55 pm

Sometime people forget you need to remove all spark plugs from the cylinders not being checked when running the check.
Also, was this a "wet check" or "dry check".

Dry check would be a cold engine that has been sitting off for a while (overnight)
Wet check, a warm engine that was recently shut off right before test.

Regards,
Dana

pmarshal · Post by **pmarshal** » Thu Mar 06, 2014 8:30 pm

Also ensure throttle is fully open to allow air in.

djnippa · Post by **djnippa** » Wed Mar 12, 2014 5:59 pm

I had my Sceptre Mk2 tested pre-rebuild (same 1725 engine as yours), and the compressions were 175, 150, 150, 125.

Rootes1725cc

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