(‘68 L68 427)
The prior owner had disconnected and capped off the sender at the block because the connection at the gauge had leaked oil all over the radio and carpet. The carpet was replaced and he denied any knowledge about the gauge and the radio not working.
Not sure exactly why but on my list of to dos I’ve been putting this one off.
He had a copper line hooked to the gauge and hanging in the engine bay but the factory line is plastic. Ron at Corvette Paramedics says that’s what they install and never had a problem, he should know right ?
So that’s what I put in. I installed an elbow at the block to aim the line straight up and bolted a ring to the block to support/guide it as shown in my AIM manual. I used Teflon tape on the pipe threads and assembled the compression fitting wet with marvel mystery oil to prevent galling. A length of washer hose was slipped over the line to protect it from chaffing or heat.
The AIM manual shows the line taped to the tach cable and entering thru the firewall together. I’ve got a new grommet to install first. Hope this all works as planned
The weather has gotten warm and I’d rather be driving than wrenching.
Ive got the proper ignition switch in place, all new vent and climate cables are in and working perfectly. New speakers have been installed front and back and the radio though not fully installed was tested and sounds great.
Hopefully all new center gauges will be installed tomorrow. Keeping my fingers crossed it goes well. Still have some parts to replace like the lower shifter boot which was another thing ignored when it had its “total restoration” done. I make it all right though.
** btw, Thank you again Terry (tfringo) with your help and getting me the ignition switch bezel. That’s a part that is otherwise impossible to find for a ‘68 now. Yes very much appreciated!

 

That looks like you did a real nice job there Lt. Mike! I replaced mine many years ago but chose to use the SS Braided line in place of the nylon tube. The nylon gets brittle with age and since I wanted to do the job once I went with the -3AN SS Braided line and even put a loop in it to allow movement of the engine without stressing any of the parts.

I have a copper line kit that I bought before finding the -3AN SS Braided line kit. I do believe that the Nylon is better than the copper line as I have seen to many copper lines break on Boats. You did a fine job protecting the parts and I doubt you will have to mess with it for a long time! I like the way you secured it with the line clamps, it looks very professional!

On my right leg I still have a scar from an oil seal that blew out on a Road Racing motorcycle back in the mid 1970's. That scar reminds me often of what happens to skin makes contact with 200* motor oil. It burned me through the leathers I had on. That scar is near the one I got from my Uncle's 1969 Corvette with Hooker Side-pipes. I decided that I would never want to have the chance of Hot engine oil shooting out from under the center console gauge cluster on to my legs or those of my passenger. Call me paranoid but I play it extra safe when dealing with HOT oil. I also wondered if Hot motor oil could short out the electrical parts down in that area, namely the ammeter.

You are making great progress on your Corvette!

 

The amp meter did get contaminated with oil and the needle sticks in a given position. The clock the one thing that needed oiling was clean and dry. Figures right ? Once I oiled that it started working again.
I bought a gauge package off eBay for about $100 that included the fuel, temp, amp, and oil gauges.
I originally thought my temp gauge was good but removing it from the panel I discovered that if I blew on it the needle spun like a pinwheel. Pretty sure that’s not good .
I also changed the tach cable that was dry, cracked and worked when it wanted. I’ll give that half a chance to solve that problem but I’m thinking I’ll probably have to change the worm gear.
I branded myself once on my Valkyrie’s side pipes once. I knew better than to wear shorts but we just wanted to ride into town for ice cream

 

the plastic line was for small blocks, the copper line was for big blocks. THe plastic lines fail really easily and the copper is definitely more reliable as its a hardline. The best is the braided steel lines but for originality the copper is what ou want

 

'68 Was a full plastic line block to gauge and in '69 they went to a 10" length of copper to the top the head then joining plastic tubing to the gauge.
Every parts resource and manual I've found reflects this. I'm concerned with abrasion which is why I used the washer hose to protect the line at the block and will cover the rest of the line with a braided covering. While it will do nothing for burst strength it will prevent abrasion from vibration.
The line that failed previously in my car was copper and had failed where it connected to the gauge. Copper isn't fool proof. Don't put too much faith in braided line either. It's got strength against bursting but inside its just another rubber hose that will eventually harden and crack. Like anything else these things don't last forever and require periodic inspection.
Does it get done? For the most part no.
A good example of this is that in the owners manual under "clock" it's paragraph ends with "Your clock should be cleaned and oiled periodically". Who does that? No one. That's why its taken for granted that they all "fail" and stop working. So people spend the $180 for a new clock or do without saying that's just how they are. Funny thing though if you remove it, remove it's cover and oil it as recommended they work again.
My point is maintenance and inspection is key. Aircraft mechanics do what is called "an annual" where the entire aircraft is inspected for potential issues and things are replaced if showing signs of wear.
This is the kind of thing we need to do too. It doesn't need to be as extensive, just the things like this. Probably best done during winter lay up.

 

Not really as simple as that: up to '68 (I believe) the line was steel from the block to the gauge. Then in '68 it changed to all nylon for all engines... however in '69 the small-blocks retained the all-nylon but for big blocks a short piece of copper at the block was used that then connected to nylon to the gauge. If I had a '68 big block, I'd follow the '69 modification; those GM engineers and warranty guys wouldn't make changes they didn't have to.

 

My 1968 C3 with it's 427 was made in October of 1967 and had NYLON tubing from the engine to the oil pressure gauge. When I disconnected it from the gauge the first time it was really "on there" and had a lot of wear and tear. Early on I went ahead and put a small vacuum hose over the nylon tubing to protect it in the tight turns and anyplace it could rub under the dashboard. I don't think that my 427 ever had a copper line from the factory. Copper lines can break more easily than the Nylon tubing and I personally would trust it even less. Copper doesn't do well with the constant vibration and or shaking. Even steel lines can break if they are allowed to shake while being used. The better secured a line is the less chance they will break from vibration.

The restoration shop I use also suggested that I replace the Nylon tubing with new Nylon tubing when they re-installed the 427 for me.

I understand that SS Braided lines are still rubber under the SS sheath and I will replace it after 20-25 years but I will still replace it with another SS Braided line as they are durable, abrasion resistant and virtually burst proof.

 

If you change your mind and use -3 you can buy -3 brake lines of various lengths with the ends already installed. Just a thought.

 

Was considering that with possibly NiCopp line which is the easiest line I have ever worked with.
Not having a fun day. Went to swap out the old for new gauges and the resistor on the fuel gauge crumbled when I went to remove the nut. Was being gentle but still broke…


I tried to find a replacement without luck so I called Ron at Corvette Paramedics.
Ron said that the repo gauges have a notation to not use the external resistor so I might be ok. Hope he’s right.
Then remounting the right kick panel it broke again where the ear goes under the sill plate. It was broke when I got ot. I super glued it but obviously it didn’t hold so off to Lowes again for screws I needed anyway and some JBWELD. I super glued it again and built up the back side with the JBweld.
Hopefully it will hold .

 

I’m not here to bash but below is an excerpt from the NHRA sportsman rule book for 7.50 and under. 1.10 OIL SYSTEM

Accu-sump, dry-sump tanks, oil filters, oil supply lines, etc., prohibited in driver compartment and outside of frame and/or steel body / fenders. Oil pressure gauge and line permitted in driver compartment. Metal or steel braided line mandatory, maximum 3/16-inch (4.76 mm) inside diameter. Power enhancing additives prohibited.

So why is a metal or stainless braided line required if you have an oil pressure guage in the car? Well fire and the fact nylon melts would be a good reason. You are 100% correct that metal lines fatigue and crack which is a very valid concern.

Using a 1” socket make a coil of 2-3 wraps of copper tube at the bottom most portion of the line. Not a bad idea to have one near the gauge too if possible. Or you could put in a braided line. My brothers 68 still have the OE line and I’m damned suspect of it

 

Trying to stay along factory lines as much as possible. A numbers matching convertible L68 powered ‘68 is worth maintaining its originality otherwise I’d go with an earlier suggestion and mount an electrical oil pressure from. ‘74 running a wire to a sensor and be done with it.