The mechanic that i learned from and worked for always said 3 thing about
compression tests.
1. Engine warmed to running temp.
2. All spark plugs out.
3. Throttle open wide.
>===== Original Message From "Paul Hunt" <paul.hunt1@virgin.net> =====
>I've been shouted down on this before but my compression tester instructions
>clearly state that the plugs should be removed and replaced with the gauge
>one at a time i.e. the test is done with compression on all four cylinders
>not just the one with the gauge in. It also says throttle wedged wide open.
>
>PaulH.
>http://freespace.virgin.net/paul.hunt1/
>
>-----Original Message-----
>From: Skye Poier <skye@ffwd.com>
>To: stevejp2@juno.com <stevejp2@juno.com>
>Cc: MG Nuts <mgs@autox.team.net>
>Date: 23 April 1999 02:46
>Subject: Re: Compression
>
>
>>Word on the street is that stevejp2@juno.com said:
>>> I am going to check out a 79 MGB that I am interested in buying tomorrow
>>> and I can not find the values I should get in a compression test
>>> anywhere. Off to get a Haynes manual later. Does anyone have an idea
>>> what the compressions should be?
>>
>>http://www.mgb.bc.ca/reference/specs.html
>>
>>Compression:
>>18G engines, 8.8:1, 160psi @ 275rpm
>>18V engines, 9.0:1, 170 - 195psi @ 275rpm
>>
>>Assuming the compression ratio is stock. Pull all the plugs before
>>you check, btw. Might want to adjust the valves too.
>>
>>FYI my '66 B gets about 145-150 psi and runs very well.
>>
>>Low readings in both cyl 2 and 3 generally point to blown head gasket
>(cheap)
>>or cracked head (expensive). Usually accompanied by clouds of white
>>smoke from the tailpipe.
>>
>>Skye
>>
>>--
>>1966 MGB The MGB Experience __,__\__ Safety Fast!
>>GHN3L-70307 http://www.mgb.bc.ca/ (_o____o_) MGOFR 1.375
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