<VV> Dead cylinder

[Jim Houston]

I have valve action.  I applied a differential compression tester and 
the air is leaking out of the intake valve.  I guess the next step is to 
remove the head and see what's up in there...

Jim Houston


Roger Gault wrote:
> Real zero compression means you have a big hole or no valve action.
> Is air pumping in and out of the spark plug hole?  I'd expect that if a
> valve wasn't moving.
>
> If the lifter was collapsed, you should have major clicking noises.
> If you have a dropped valve seat I'd expect a loud tick also.
>
> Run the engine with the valve cover off and see if the valves are going up
> and down like the adjacent cylinders.
> If all that looks right, you have a broken (or holed) piston or valve head.
> If you have an air compressor, try blowing air into the spark plug hole and
> seeing where the air or hissing noise comes out.  Valves?  Block?
>
> Roger
>
>
> ----- Original Message ----- 
> From: "Jim Houston" <tampatexan at tampabay.rr.com>
> To: "Virtual Vairs" <virtualvairs at corvair.org>
> Sent: Friday, May 12, 2006 3:03 PM
> Subject: <VV> Dead cylinder
>
>
>   
>> Well, I need some help!  I was on the way home from work the other day,
>> and as I left a light, my faithful '65 110HP  4 speed developed a miss -
>> or should I say, a severe miss?  I checked all the obvious stuff (plugs,
>> plug wires, etc), and finally did a compression check.  Number 4
>> cylinder has zero compression.  The others are between 195 and 200 (on
>> the brand new compression gauge I bought just for the occasion).  I
>> removed the valve covers and can't find anything wrong.  Following the
>> directions in both the GM Shop Manual and the Corvair Basics manual, I
>> attempted to set the valves on that cylinder.  About the only thing I
>> found that appears wrong is there is no "free play" on the intake
>> pushrod - - there isn't any "spring" to the lifter.  Is it possible that
>> the lifter is collapsed and not extending enough to open the valve??
>> Other than that, I have no ideas left.  The engine wasn't making any
>> terrible noises before the miss started, and didn't make any after the
>> miss started, so I don't think anything mechanical has broken inside.
>> Should I be ordering some lifters?  What are the chances that there is a
>> hole in the piston?  Any further suggestions would be greatly appreciated.
>>
>> Jim Houston
>> '65 Monza Coupe
>> Brandon, FL
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