Re: Stuck Valves, Morning Sickness, and the Rope trick.

[Tom Downey]

'We all know that all metals expand when heated, So, when thhe engine
is hot and running the valve guide is larger than when it is cold.

The Valve stem is too, but the brass guide will expand more than the
steel valve stem, thus the gap between them can fill with lead while
running and after the engine has cooled off, the guide will use the
lead to grab the valve stem, and if the valve is open it will stay
opne, until th eengine heats up again.

This is commonly called "morning sickness", it chuggs a little in
the morning, but is OK the rest of the day.

This is the symptom of more to come. IF the valve happens to stick
open during flight, the piston is what will close it, not the spring.

Many times the piston will strike the valve head at an angle and
break the stem, allowing the valve to be sucked into the combustion
chamber, Commonly called swallowing a valve. (not a good thing)

The rope trick,,

find a piece of 5/16 climbers rope about 4 feet long, Tie a simple
knot close to one end. climbers rope is that really flexable stuff
that is soft and won't scratch anything.

Remove a spark plug of the effected cylinder, place the engine at
BDC of the intake stroke ready to come up on the compression stroke.

Twist the rope as you push it into the spark plug hole, bring the
engine up on the compression stroke until the rope compresses aginst
the valves, holding them on their seats allowing you to remove the
springs and keepers.

After the springs and keepers have been removed rotate the engine
backwards to DBC.

Tie a piece of dental floss about 6 feet long to the valve stem at
the keeper grove, and pust the valve out of its guide.

wrap the dental floss left sticking out of the valve guide around
the flutes of the proper guide reamer, then ream the guide, slowly
carefully once in, continue turning, and pull out.

unwrap the floss from the reamer, flush the guide with something
like WD40, (get the trash out of the guide) and pull the valve back
into place using the floss and maybe a little help from the piston
and rope.

Bring the piston to TDC the rope will hold the valve until you can
replace the springs, keepers, and valve covers. remove the rope
replace the spark plug.

Bye Bye morning sickness.'

[Mike Danielle]

'Only one thing to add to Tom's technique: Liberally grease up the reamer
before this operation to hold the chips. I've seen this method used on all
kinds of engines and it saves lots of labor.

Mike in Oregon

----- Original Message -----
From: "Tom Downey"
To:
Sent: Monday, July 11, 2005 9:45 PM
Subject: [fairchildclub] Stuck Valves, Morning Sickness, and the Rope trick.


> We all know that all metals expand when heated, So, when thhe engine
> is hot and running the valve guide is larger than when it is cold.
>
> The Valve stem is too, but the brass guide will expand more than the
> steel valve stem, thus the gap between them can fill with lead while
> running and after the engine has cooled off, the guide will use the
> lead to grab the valve stem, and if the valve is open it will stay
> opne, until th eengine heats up again.
>
> This is commonly called "morning sickness", it chuggs a little in
> the morning, but is OK the rest of the day.
>
> This is the symptom of more to come. IF the valve happens to stick
> open during flight, the piston is what will close it, not the spring.
>
> Many times the piston will strike the valve head at an angle and
> break the stem, allowing the valve to be sucked into the combustion
> chamber, Commonly called swallowing a valve. (not a good thing)
>
> The rope trick,,
>
> find a piece of 5/16 climbers rope about 4 feet long, Tie a simple
> knot close to one end. climbers rope is that really flexable stuff
> that is soft and won't scratch anything.
>
> Remove a spark plug of the effected cylinder, place the engine at
> BDC of the intake stroke ready to come up on the compression stroke.
>
> Twist the rope as you push it into the spark plug hole, bring the
> engine up on the compression stroke until the rope compresses aginst
> the valves, holding them on their seats allowing you to remove the
> springs and keepers.
>
> After the springs and keepers have been removed rotate the engine
> backwards to DBC.
>
> Tie a piece of dental floss about 6 feet long to the valve stem at
> the keeper grove, and pust the valve out of its guide.
>
> wrap the dental floss left sticking out of the valve guide around
> the flutes of the proper guide reamer, then ream the guide, slowly
> carefully once in, continue turning, and pull out.
>
> unwrap the floss from the reamer, flush the guide with something
> like WD40, (get the trash out of the guide) and pull the valve back
> into place using the floss and maybe a little help from the piston
> and rope.
>
> Bring the piston to TDC the rope will hold the valve until you can
> replace the springs, keepers, and valve covers. remove the rope
> replace the spark plug.
>
> Bye Bye morning sickness.
>
>
>
>
>
> Yahoo! Groups Links
>
>
>
>
>

'