oletrucks
[Top] [All Lists]

Re: [oletrucks] compression and leak down

To: oletrucks@autox.team.net
Subject: Re: [oletrucks] compression and leak down
From: jrdorsey <jrdorsey@strato.net>
Date: Sat, 31 Jul 1999 10:46:26 -0700
John,

        I"ve got some bad news for you. The odds are that you've got a cracked
cylinder head on #4. The 216/235 has always had cracking problems, and
they always crack across the valve seats. After awhile the crack across
the exhaust seat will cause the valve to burn. 

        The sweet smell you get is antifreeze in the exhaust. The crack will
heat up and seal while the engine is running, but when you shut it off
the metal cools and the crack opens allowing antifreeze to seep into the
cylinder.

        There are two courses of action. Either pull the head and replace if it
is cracked, or rig it until you HAVE to fix it.

        If you want to rig it here's what I would do, get some K&W block seal
and put it in the radiator then turn the exhaust valve on #4 clyinder. 

        To turn the valve on #4, run the adjuster on the rocker arm all the way
loose, then clamp a pair of vise-grips on the stem of the valve, push
down and turn. I would turn it about 1/4 turn. That takes the burned
section away from the crack to slow down the progression of the burned
spot. While you're there you might want to turn the #3 exhaust valve
also,  just in case it's cracked and starting to burn.

        This rigging is only temporary, and I would start looking for a
replacement head now. If it turns out you don't need it you can always
sell it.

John (jrdorsey)
3800 panel

cupola2@worldnet.att.net wrote:
> 
> Dear Group,
> Took my '54 3100 in for a compression and leak
> down test today, but I'm unsure what it all
> means.  Here are the fugures they gave me.
>    Comprssion/PSI     Leak Down %   Hot  8K
> #1   130               40% rings
> #2   125               50% rings
> #3   105               50% valves
> #4   85                70% equally
> #5   120               15% valves
> #6   125               20% equally
>  Of course, they would have liked to have kept my
> truck.  There is no smoke coming from the tailpipe
> and I'm no using any oil that I can tell.
> Sometimes, when I start her, I get a funky, sweet
> smell that goes away after a few minutes.  Other
> than that, I like driving my old truck.
> What do all these figures mean?
> 
> John 54 3100  235 six
> oletrucks is devoted to Chevy and GM trucks built between 1941 and 1959
oletrucks is devoted to Chevy and GM trucks built between 1941 and 1959

<Prev in Thread] Current Thread [Next in Thread>