Spark Plug To Compression Testing Nipple

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?

 

Years ago to make a differential compression tester, I took a unshielded 18mm plug and broke the porselin with a hammer. Then brazed a pipe union to the steel.

 

Much easier just to buy one. Do a google image search for Spark Plug Compression Adaptor. Many available

 

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.

 

That sums up HBA!

 

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?

 

Dan,
Thanks!

 

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.