[fleming23]

I am struggling to find a plug for the back of my motor. I removed my mechanical gauges and am in the process of swapping over to an SS dash kit. The 3 pod gauge cluster I had mounted under my dash had the plastic tubing running to a 10mm x 1.0 fitting that screwed into the back of my motor just behind the intake.

Here is an image of basically what I have

I need either a 10mm x 1.0 plug or a -4 an plug to cap the fitting.

And this is a picture of the actual fitting


I need to plug this hole or I am going to have oil all over my engine bay....Am I missing something because I can not find a fitting to plug this hole anywhere. I tried O'Reilly's, Autozone, Advance and Summit...

 

[fleming23]

Here is where the fitting is located to possibly give you guys a better visual


Here you can see a shot of the side of the distributor cap

 

[BillK]

Eric,
The threads in the block are 1/8" National Pipe Thread, definitely not 10MM or anything metric. You should be able to find a 1/8" NPT plug at any hardware store, Home Depot etc. Your machine shop probably has them too.

 

[fleming23]

I wonder if the mechanical oil pressure gauge came with this fitting and the builder filled the hole with some sort of sealer to make it work.

I will buy a 1/8" plug and hopefully it'll thread correctly. Definitely makes my search much easier!

 

[BillK]

I will buy a 1/8" plug

Eric,

Make sure you understand that it is 1/8" NPT (national pipe thread) which is a lot different than a "normal" 1/8" thread, if such a thing even exists. The plug will actually measure closer to 3/8" diameter.

http://en.wikipedia.org/wiki/National_pipe_thread

Look in the plumbing section.

Your fitting might be 1/8" pipe. Are the threads slightly tapered ? Hard to tell from the picture. Or they might just be a SAE straight pipe thread and happen to be close enough that it managed to seal ok. But in any event, the hole in the block is 1/8" Pipe and has been since 1955

 

[fleming23]

Thanks Bill! The threads are slightly tapered so that makes sense about needing NPT. At any rate, I'll take another trip to the part store today and hopefully find what I need. If only the Summit store were closer...

I appreciate the help!