<VV> No compression in #3 - One very bad piston !

[Charles Lee]

Good to know it was not catastrophic - at least not yet, if I find the pieces before it is !!!

#1 and #5 look OK, but as long as I'm pulling #3 piston out, I may as well pull them out too, and see if there's anything suspicious going on there.

I really think it's worth doing right, but I want to have some left for gas ;>}) !!! 

Charlie


  ----- Original Message ----- 
  From: Mark Durham 
  To: Charles Lee 
  Cc: Virtual Vairs 
  Sent: Monday, October 18, 2010 8:37 AM
  Subject: Re: <VV> No compression in #3 - One very bad piston !


  Charlie, 

  the fact that you have a piston that fell apart as it did does not mean there was a causal factor other than very old parts. If the pieces came off in big chunks, you have pulled the pan to see what is there, also look by the camshaft area, the area where oil can fall back into the pan is small, but if everything is pretty much accounted for, then it may just be aging parts helped by the dymanics of the heating and cooling and moving parts. That is why the cylinder walls are in such good shape, there was no "catastropic event". 

  Take a good look at the crank journals and rod bearings. If not all scratched up and clearances are normal, then you should be good to fix the engine. The GM manual says the barrels can be worn to up to .005, and put new rings in and go. If there is a ridge at the top, that is usually about .010 and they need bored. But if you cannot feel a ridge (makse sure to clean the carbon off the top where the ring does not go first, with some crocus cloth, then check it. 

  BUT: One note of caution. If that group of pistons have had age related issues, you have one already, then the other 5 may be just down the road in doing the same thing. They may not. Since you do not have any valve leakage, I would suggest at a minimum that you replace the pistons, Rings, hone the barrels, and do the gaskets.

  Larry S has cast pistons for about $159 a set, Grant Cast Rings, $47, on ebay. both in any size and Clarks has a top overhaul gasket set for about $86.   

  My EM 102 hp has 2 cylinders that have compression issues, and its puffing more smoke on startup now than this time last year, so I'm going to pull it apart this winter and do what needs to be done, probably just what I said above.

  Mark Durham 


  On Sun, Oct 17, 2010 at 10:26 PM, Charles Lee <Chaz at properproper.com> wrote:

    Good point, but yes, they were in place on both sides, which I could see
    before when I tried to clean the fins, which I can do much more easily now,
    right ?

    My damage is bad, but nothing like the piston in your photo !  What happened
    to that one ????

    Charlie

    ----- Original Message -----
    From: "J R Read" <hmlinc at sbcglobal.net>
    To: "Virtual Vairs" <virtualvairs at corvair.org>
    Sent: Sunday, October 17, 2010 10:02 PM
    Subject: Re: <VV> No compression in #3 - One very good reason !


    >I have a question.
    >
    > Was there a baffle in place against the cylinder walls - held on with two
    > spring clips?  If not, I chalk that up as the root cause of your holed
    > piston.  Also, if not - it would be a wise move to drop the lower shroud
    > on
    > the other side and see if that baffle is in place.  If not, you have to
    > pull
    > the push rod tubes on that side as well in order to get the baffle in.
    >
    > Later, JR
    >
    >
    > ----- Original Message -----
    > From: "Charles Lee" <Chaz at ProperProper.com>
    > To: "Virtual Vairs" <virtualvairs at corvair.org>
    > Sent: Sunday, October 17, 2010 8:30 PM
    > Subject: Re: <VV> No compression in #3 - One very good reason !
    >
    >
    >> Ed,
    >>
    >> You got closest to the bulls-eye with that theory !
    >> Considering how nice and clean the cylinder walls were, I was not
    >> expecting
    >> this ...
    >>
    >> Not quite broken off, but very close :
    >> The 3rd "story" is missing 1/4 of the entire side !
    >>
    >> Here's what I found :
    >> www.yourbuyersinn.com/Cars/Corvair/1967MonzaCylinderWallPix.htm
    >>
    >> OK, now to build that "shop" in my shed - too much to do in the driveway
    >> !
    >>
    >> I Love My Corvair (keep saying that ...)
    >>
    >> Thank you for your support  ;>})
    >> Charlie
    >>
    >> ----- Original Message -----
    >> From: <wfcc at mediacombb.net>
    >> To: "Charles Lee" <Chaz at ProperProper.com>
    >> Cc: "Virtual Vairs" <virtualvairs at corvair.org>
    >> Sent: Sunday, October 17, 2010 5:48 PM
    >> Subject: Re: <VV> No compression in #3
    >>
    >>
    >>> Charles,
    >>> One thing I haven't heard mentioned here-Does the top of the piston in
    >>> the
    >>> # 3 hole go up and down  when the engine is turned over ? I have seen
    >>> more
    >>> than one Corvair piston break in two at the ring grooves. That will give
    >>> you a real fast Zero compression situation with a bit of knocking.
    >>>
    >>>                         Ed Lindsay
    >>>
    >>> West Florida Corvair Club
    >>>
    >>
    >> _______________________________________________
    >> This message was sent by the VirtualVairs mailing list, all copyrights
    >> are
    >> the property
    >> of the writer, please attribute properly. For help,
    >> mailto:vv-help at corvair.org
    >> This list sponsored by the Corvair Society of America,
    >> http://www.corvair.org/
    >> Post messages to: VirtualVairs at corvair.org
    >> Change your options:
    >> http://www.vv.corvair.org/mailman/options/virtualvairs
    >> _______________________________________________
    >
    > _______________________________________________
    > This message was sent by the VirtualVairs mailing list, all copyrights are
    > the property
    > of the writer, please attribute properly. For help,
    > mailto:vv-help at corvair.org
    > This list sponsored by the Corvair Society of America,
    > http://www.corvair.org/
    > Post messages to: VirtualVairs at corvair.org
    > Change your options:
    > http://www.vv.corvair.org/mailman/options/virtualvairs
    > _______________________________________________
    >

     _______________________________________________
    This message was sent by the VirtualVairs mailing list, all copyrights are the property
    of the writer, please attribute properly. For help, mailto:vv-help at corvair.org
    This list sponsored by the Corvair Society of America, http://www.corvair.org/
    Post messages to: VirtualVairs at corvair.org
    Change your options: http://www.vv.corvair.org/mailman/options/virtualvairs
     _______________________________________________