<VV> Diagnose engine "knock" ? valve seat or ring damage ?

Charles Lee Chaz at ProperProper.com
Sat Oct 16 14:59:56 EDT 2010


Thanks ~~~

I'll check cylinder walls soon and see if they are scored in any meaningful way.

I had bet on valve seat dropped as a result of "0" compression, and thought that rings would give low, but not "0," compression ?

We'll see soon enough !

It's been a L-O-N-G time since I ripped an engine apart, and I NEVER went this far - never removed or replaced heads, but it's an interesting journey.

Good thing I LOVE MY CORVAIR.  I do not even care to do this to my DOA Fords, although maybe it'll give me the confidence to tackle them eventually ?

Here is a link to the current progress, and I'll put more, better pix on this same link when I get them ...
www.yourbuyersinn.com/Cars/Corvair/1967MonzaCylinderHeadRemoval.htm

Link to "main menu" is picture of my car at the top of each page)

Thanks for all your help !
Charlie

PS:  I may change my name to Charlie "The Situation" ?


  ----- Original Message ----- 
  From: Mark Durham 
  To: Michael Kovacs 
  Cc: Charles Lee ; VV 
  Sent: Saturday, October 16, 2010 11:42 AM
  Subject: Re: <VV> Diagnose engine "knock" ? valve seat damage


  Mike is right, should have mentioned that if you have 0 compression that usually is a stuck or burned valve or piston/ring damage.
  Since you have the head off, lock down the cylinders by putting some tight fitting hose on the head studs and pull the other plugs and pull the engine through so you can see the condition of the cylinder walls, one at a time. Compare them. . Wear will show up more at the top where there may be a difference between where the rings run and at the top where they don't. Clean that with some crocus cloth to get any carbon off and see if there is a ridge there. Look closely at the three piston heads. You had one with no compression, two with compression. Look for deep vertical scratches in the cylinder wall (broken ring) damage to the head, difference in the coloring, amount of carbon?

  Also a cylinder using oil will usually coke up on the valve stems and back of the valves. I would think the cylinder with low compression would have more, as it probably has been using more oil longer, but if the engine is old, all three (six) would be that way.
  Got a digital camera? Take a picture and post it for us. 
  Off to build shelves in my daughters garage.

  Mark Durham


  On Sat, Oct 16, 2010 at 10:30 AM, Michael Kovacs <kovacsmj at sbcglobal.net> wrote:

    Charlie,
     You need a valve remover tool. Just keep track of which valve goes where. Don't
    loose the keepers. A smack with a mallet will sometimes loosen up on the keepers
    that wont let go of.  You can check the valve looseness by just pushing the
    valve back into the guide. It may take a good machine shop to really check this
    condition. Hope you just need a valve seat cleaning and a regrind.

    You can check for valve leakage by reinserting both valves in the head and
    adding some light oil like kerosene to the head to see where any potential
    leakage is. O in # 3? I cant see why.

     Hope others will add to this basic stuff. Where do you live? Any experienced
    corvair people near you?MIKE KOVACS





    ----- Original Message ----
    From: Charles Lee <Chaz at ProperProper.com>

    To: shortle <shortle556 at earthlink.net>; virtualvairs at corvair.org
    Sent: Sat, October 16, 2010 1:35:34 AM
    Subject: Re: <VV> Diagnose engine "knock" ? valve seat damage

    Wow !  I would have bet that # 3 would have an obvious indication of valve
    seat damage, but it does not show any valve seat displacement ?
    www.yourbuyersinn.com/Cars/Corvair/1967MonzaCylinderHeadRemoval.htm#CombustionChambers


    I'm still convinced that #3 vale seat was the cause of my "knocking" when
    the engine wasn't even warm enough to do that ?
    Would the area around the valve be worn if the seat was loose ?

    The combustion chamber is wet though and the top of # 1 and # 5 are chock
    full of carbon, probably from messing with the carburetors, trying to get
    them right.

    Any ideas ?  I've never removed valves before, so what do I need to know
    that will surprise me if I try this ?

    Thanks again guys !
    Charlie



    ----- Original Message -----
    From: "shortle" <shortle556 at earthlink.net>
    To: "Charles Lee" <Chaz at ProperProper.com>; <virtualvairs at corvair.org>
    Sent: Friday, October 15, 2010 5:41 AM
    Subject: Re: <VV> Diagnose engine "knock" ?


    > Odds: Even money. Did you have good compression in all 6 cylinders before
    > you replaced the parking brake cable?
    > Timothy Shortle in Durango Colorado
    >
    >
    > -----Original Message-----
    >>From: Charles Lee <Chaz at ProperProper.com>
    >>Sent: Oct 15, 2010 12:43 AM
    >>To: virtualvairs at corvair.org
    >>Subject: <VV> Diagnose engine "knock" ?
    >>
    >>What are the odds that I'll find a dislodged valve seat on #3 ?
    >>
    >>Charlie
    >>

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