Oil Pressure Gauge Fitting '68 to '73
 

Anyone know the diameter and pitch of these threads?



https://cimg0.ibsrv.net/gimg/www.cor...026bed06dd.jpg

Well, it cost me $15.00 to find out....:ack:

For future reference, they are both 5/16"-24.

Another question....Does this fitting have to a right angle in C3 Corvettes?

:D

We weren't ignoring ya. Just no one who had one apart saw your thread. It's tough to get to, and the old axiom If it ain't leakin', don't touch it was also working against you.
It should be a 90 degree fitting because the Gauge Panel butts up very close to the Firewall. It therefore eliminates a sharp bent of the nylon Oil Line.

Steve

Thanks for the info. I bought the fitting to experiment with, hoping there was something available to adapt it to a -3 AN fitting which could be used with a braided stainless oil line. It's the same diameter as 1/16th pipe thread, but the pitch is wrong.

I was bored and it was cold out, so I whittled one off in my lathe. Took many hours, so this will be the first and last.:D



https://cimg3.ibsrv.net/gimg/www.cor...03dcd15e3b.jpg

The braided line I am using is 4an. I found an adapter on Amazon that works but it wasn’t easy to find. Will look for it if you are interested. Not aware of a braided oil gauge line that is 3an.

Hmmmm...I had no trouble finding -3 AN line. They are usually described as brake line, but will work with oil pressure gauges as well.

https://www.speedwaymotors.com/Braid...sku=91031845-3


https://www.summitracing.com/int/par...0308/overview/

Gotcha, I am using the Autometer line and it is -4 as was the Allstar at Summit but I was searching for the oil gauge line. Didn’t know the brake line stuff would work.����

I just replaced my 40+ year old nylon line with -4 braided line. The fittings in the block and the gauge are 1/8NPT. I used 1/8 NPT to -4 90* fittings.

This is correct - they are NOT "both 5/16"-24" although they are close!

My 69 gauge was definitely not 1/8 NPT but 5/16-24. None of the adapters in the Autometer kit fit. Hard to find the 5/16-24 to -4 adapter but I did find one. I will post a pic as my gauges are out of the car.

This is the kit I used:

https://cimg7.ibsrv.net/gimg/www.cor...baa04c36ee.jpg

Summit PN SUM-G2960 :thumbs:

Everything I know about this fitting:


It is 5/16-24...it is not tapered.



https://cimg8.ibsrv.net/gimg/www.cor...ccc38d5ed1.jpg



This is a 5/16-24 bolt with 2 nuts on it. Below that is the fitting with the same nuts.



https://cimg0.ibsrv.net/gimg/www.cor...90ef9b8f56.jpg



This is a 1/8" pipe fitting, compared to the gauge fitting. It is much larger.



https://cimg0.ibsrv.net/gimg/www.cor...ae64b8bccc.jpg



This is the tube fitting on the 5/16-24 bolt. It fits on the gauge fitting.




https://cimg1.ibsrv.net/gimg/www.cor...d70441698c.jpg

That is the same fitting as on my 69 Buns, definitely was not 1/8 NPT.

Now THAT is clarification! :D

Steve

Can you share the information of where did you find the adapter?

That post is from 4 years ago.