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Re: Compression check and advice please

To: BDurgin1@aol.com
Subject: Re: Compression check and advice please
From: Barney Gaylord <barneymg@ntsource.com>
Date: Wed, 10 Feb 1999 13:34:56
At 10:23 AM 2/10/99 -0800, Kelvin Dodd wrote:

>Did a cold compression check on my car and found the following:
>Cyl 1  145#
>Cyl 2  140#
>Cyl 3  110#
>Cyl 4  145#
>
>Added a little oil to the No. 3 cylinder and the pressure went up to 115
only.

Probably a burned exhaust valve.  Head will have to come off, sorry.  But
if the performance doesn't bother you, ya could just drive it like that
until it does.

>.... and I get a puff of white smoke when I accelerate hard and shift up
or down, ....

High RPMs, then foot off gas, equals high vacuum in intake on overrun.
This sucks a little oil down the intake valve guides and causes the white
smoke when you hit the gas again.  Valve guides are likely somewhat worn,
should be replaced next time the head is off, but no big rush either.

>.... Should I be concerned?

Nah.  Drive the wheels off it until it runs bad, then pull the head for a
valve job and new guides (and maybe hard seats).  When the compression gets
down around 90# on one cylinder it might get to be a little hard to start,
and it may idle a little rough, but hey, it's an MG.  Drive the sucker.

$.02,

Barney Gaylord
1958 MGA with an attitude


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