Yes, I checked old posts, no, I didn’t find anything specific about my question. I’m considering putting some gauges in my car and I don’t want to use the plastic capillary tubes for my oil gauge. I will run copper tubing through a grommet in the firewall and I was wondering if some sort of anchor on the fire wall before the grommet would be useful. I don’t know if there are grommets widely available that are snug enough for a 1/8” capillary, so I was thinking of having an anchor close to the grommet to cut down on vibration and subsequent metal fatigue. I may be overthinking this, but I don’t want to take an oil bath inside my nice interior of my ‘55 Chevy. Anyone done this?
Run line from engine and coil it up in about a 21/2” coil 3 times then run it through the grommet. You can usually get an ***ortment pack at Advance or Auto Zone that will have one small enough. If not small enough a small shot of Permatex ultra adhesive/sealer in the center of the grommet will tighten it right up. After you do that on the other side of the firewall make the same size coil of tubing again and run it to the gauge. Too bad the steel line isn’t available any more. This has worked for me many times in the past.
SS327 Nailed it! The coils dampen the vibrations from the engine and allow a bit of wiggle without stressing the tubing, you don't want it locked down tight on the engine side of the firewall gromet.
I used jic fittings though out my build, here is a jic bulk head fitting for the penetration through the fire wall. The line from the engine to firewall is a mock up to be made up with proper high pressure line. On the interior side I’ll make up the line with steel 3/16 lines and proper cushion clamps. All my lines vacuum, oil, and fuel pressure lines will follow suit.
I also am not a fan of the translucent plastic tubing and I also did not want copper. I found black synthetic pneumatic tubing at the local hydraulic supply that is rated to 600 psi, its black so it disappears and just about any fitting is available to make the installation clean. ( I checked and it is impervious to most chemicals so motor oil will not affect it)
What's the difference between the furnished translucent tubing & the black synthetic pneumatic tubing you bought ?
The black tubing is heavier wall thickness, and is slightly more abrasion resistant. It was designed for high pressure pneumatics in an industrial atmosphere, the black color is a plus because it is not noticeable like the translucent plastic stuff.
I used compression fittings that the hydraulic supply shop had. Sorry I do not have a photo but if you need one I will shoot one tomorrow.
I'm curious, what is the problem you have with copper lines for the oil pressure gauge? I've been running one in my Plymouth since 1965 without any problems. I did use a rubber grommet through the firewall.
I don’t have a problem with copper lines and grommets, I was after a certain look and it’s just how it kind of worked out.
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