Thanks Barney, that's exactly what I was looking for. I rebuilt the engine
5 years ago and all cylinders were treated the same, machine shop, honing,
etc. I couldn't really understand why one cylinder would be different from
the others. I'll get some penetrating oil in it right away and see what
happens. I'll let you know on Monday.
Thanks,
Ken
-----Original Message-----
From: Barney Gaylord [mailto:barneymg@ntsource.com]
Sent: Friday, November 10, 2000 2:59 PM
To: Ken Waringa
Cc: mgs@autox.team.net
Subject: Re: Broken Ring????
At 07:19 AM 11/10/2000 -0600, Ken Waringa wrote:
>.... 74 Midget (his daily driver .... wasn't running right. ....
compression check. Number one cylinder was about 100 lbs. 2, 3, & 4 came
in at about 145 lbs. .... I put a little oil in the cylinder and tried
again hoping for the same 100 lbs. Nope, it went up to about 150 lbs.
>
>I figure this means broken/damaged rings, but ....
With the nice jump to 150 with the oil added, I doubt if the rings are
broken, just more likely stuck in the grooves. Time to try some cleaning
techniques to free up stuck rings.
Start with an oil change and add a can of Rislone (if you can still find
it), which is an engine oil with very high detergent level and some
solvents added. If you can't find the Rislone you can use one quart of
automatic transmission fluid, which is also very high detergent and a good
cleaner. Just don't drive it too hard with the ATF in there, and change
the oil again after a few hunderd miles.
If that doesn't do it, remove the spark plug and put some aggressive oil
based solvent in the cylinder, such as Liquid Wrench penetrating oil. Let
it sit for a few days, or maybe up to a week, and keep adding more solvent
if it drains out past the rings. Then after a good soaking, crank it over
without starting to blow the stuff out of the cylinder (stand clear of the
spark plug port), give it an oil change, and drive it a little more.
If that doesn't get the compression up to more pallatable numbers, I'm
afraid the only course left is to pull the piston to see what's amiss. But
by the time you pull the pan and the head to get that far, you might aquire
a case of the Might As Well's, in which case you could be in for honing and
new rings on all four cylinders, or maybe even a rebore and new pistons if
it's a high mileage engine. I would take all possible steps to attempt to
nurse it into remission before conceeding to surgury.
Barney Gaylord
1958 MGA with an attitude
http://www.ntsource.com/~barneymg
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