Spark Plug To Compression Testing Nipple

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Vision_2012

Well-Known Member
Joined
Apr 21, 2010
Messages
274
Location
Shady Cove, OR
Hi,
I want to convert a spark plug to accept a quick disconnect nipple to do leak down compression testing.

I found it very hard to remove the insides of a spark plug. The inside is too hard for my drill.

Help?
 

PTAirco

Well-Known Member
Joined
Sep 20, 2003
Messages
3,528
Location
Corona CA
I welded a grease (zerk) fitting to an old spark plug to unstick a very stuck piston. Had to smash out the insides with a punch and hammer.
 

Dan Thomas

Well-Known Member
Joined
Sep 17, 2008
Messages
5,353
If you look carefully you'll see that a sparkplug is actually two pieces of metal. The skinnier top part fits into the fatter lower part, and a collar around the top of the lower part is rolled over a lip on the top part to hold it there. You can grind that collar off, or stick the plug in a lathe and turn it off, and the top part will come off and let the ceramic fall out. Tap the bottom part for 1/4" NPT and you're done.

See the joint?

EditedPlugWCallouts.png

SparkPlugTesting.jpg
 

cheapracer

Well-Known Member
Log Member
Joined
Sep 8, 2013
Messages
6,120
Location
Australian
Well, you kind of have to pick your battles. People who make their own screws instead of buying them for a nickel each rarely get finished and flying.
Sure but who said finished and flying is everyone's primary goal. It's not of course.
 
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