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Re: Ring JOB

To: mgs@autox.team.net
Subject: Re: Ring JOB
From: jfischer@supercollider.com (James Fischer)
Date: Tue, 21 Nov 1995 07:05:00 -0500
>1.      Have I blown the Oil rings on one (or more) of my pistons??

            Oil-coated plugs are not a good sign.  Has the car
            started at all since this incident?  There are only
            two paths for oil to get into the combusion chamber:
            The head gasket (hard to see how a single-point 
            failure in the head gasket would put large amounts
            of oil in all cylinders, though...) and the rings.
            (Also hard to imagine how all 4 cylinders would go
            all at once...)  Have you checked compression with
            a compression meter?

>2.      Now that I have started to pull the head, I want to replace all the
>rings for all four cylinders.  Moss sells them in a kit, but what is the
>difference between the ring kits which say:
>                          a.       std.  (I assume this means standard)
>                          b.      0.020
>                          c.      0.030
>                          d.      0.040

        This is how much bigger each ring is than the "std" size,
        in inches.  I would suggest:

            1) Pulling the head AND SAVING the old head gasket
                for examination by your machine shop.

            2) Stripping the block of everything in the way
                of external components that can be removed 
                from the block.

            3) Pulling the block.

            4) Taking the head, the block, and the gasket to
                a competent machine shop, and letting them
                see what the problem is.  They will know, since
                they can measure, cast an experienced eye, etc.

            5) While you have the engine out, you can have them
                also check the "bottom end", and replace the
                too-cheap-to-not-replace-but-pain-in-the-ass-if-they
                -fail-when-the-block-is-back-in-the-car parts like
                a few of the bearings, the oil pump, etc.

>3.      Should I wait to measure the cylinder walls before phoning in my
>order to Moss for the standard rings?

            Nope, you should let the machine shop order the rings,
            since they will make the decision of how much to bore
            the cylinders, if any.  You can "order" a bore-out to
            get slightly more displacement, but you would only do
            this after you heard their suggestions.  ("Since we
            are forced to bore the engine out anyway, let's go to
            0.030" [say "thirty-thousandths" to sound like one of the
            guys...])  Before boring MORE than suggested by the shop,
            recall that rings can only be so much bigger than their
            pistons, and that big bore-outs can paint you into a 
            corner if you have similar trouble in, say the year 
            2025, when rebuilt MGB blocks may cost $50,000.

>4.      Should I also order new cylinder liners?

            Let the shop worry about this.  

                A)  They have the proper tools, and unless you have
                    your own machine shop (in which case you would
                    not be asking these sorts of questions), you don't.

                B)  They have the skills.  All the diagnosis in the world
                    comes from one glance at the head and block by an
                    eye that has seen 10,000 blocks in the past 10 years.

                C)  They are faster than you could ever dream of being.
                    Less than a week, in many cases, faster than your
                    dry cleaners.

                D)  They can order rings, sleeves, et al from the same
                    folks that Moss buys from, thus making the 
                    price you pay LESS than Moss's price.  They also
                    know EXACTLY what to order, where you have very 
                    basic questions about rings...

                E)  If you do the strip and removal of the block, and
                    can put everything back together, you have saved
                    yourself about $400-$500, and have learned much
                    about your car in the process.  I am an engineer
                    with more gray hair than I'd like to admit, and
                    I would NEVER even think of messing about with
                    the issues that are the domain of machine shops.

                F)  A good local machine shop is easy to find.  Ask
                    your local car club, and 90% of the members will
                    narrow your down to one of two shops that they 
                    "swear by".  Pick either one, since both are the
                    sort of shop you want.
                
                G)  Make sure you order the copper head gasket either
                    through the shop or from Moss or whoever.  The
                    copper head gaskets are wonderful, and worth
                    every penny on any small-block engine.  Let the
                    shop put the head on the block, and you then
                    have a complete top-to-bottom job that they
                    will stand behind for some number of miles
                    against any and all major failures.




Scientists and Engineers try to make the future some sort of theme park.
Humanist Intellectuals wish the future did not exist.
Ecologists point out that the future may not exist, after all.

   james fischer                       jfischer@supercollider.com


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