Oil Pressure Line --68 Corvette 327

[Kurt B.]

My question pertains to the fuel pressure line that runs from the back of the engine block to the oil pressure guage in the center cluster: was the line plastic or copper? I have owned my 68 since 72 and the line presently installed is plastic but I have been told that this is not original and it should be copper. I find it hard to believe that someone replaced the line in a car that was less than 4 years old.
Please advise as I presently have the dash out of the vehicle and want to install the CORRECT line. Thank you,
Kurt # 26406

[Joe C.]

Re: Oil Pressure Line --68 Corvette 327

Kurt:

I am SURE that the line should not be copper. Copper becomes fatigued due to engine vibration and heat, and so can crack. Older Corvettes used copper clad steel lines, but the more recent (possibly circa 1970 and up) may have used plastic. Someone with a more recent specimen will shed more light on this.

Joe

[Duke W.]

Re: Oil Pressure Line --68 Corvette 327

I want to emphasize that GM NEVER, EVER used copper for the oil pressure line, but there may be some copper repros out there as the copper plated steel tubing looks the same as copper tubing to visual inspection.

As stated, copper is an unacceptable material for the oil pressure line because copper work hardens rapidly. There is a lot of vibration and relative movement between the engine and the cowl, and the work hardening properties of copper will cause a copper tubing line to crack!

If you are not ABSOLUTELY, POSITIVELY certain that your line is copper plated steel and not copper, check it with a magnet, and if it is not magnetic, replace it with a proper copper plated steel tube immediately.

We need to stamp out the copper tubing myth!

Duke

[Jim T.]

Re: Oil Pressure Line --68 Corvette 327

Kurt my original owner 68 has the plastic oil line from the back of the engine to the oil guage and it is original equipment. My 70 also has the same kind of oil pressure line. I did replace the one in my 70 a few years ago because something happened to the end that goes to the block. I purchased the replacement from GM and of course it was plastic.

[Craig S.]

Re: Oil Pressure Line --68 Corvette 327

I had a friend with a 69 427/390 that I know had the plastic line....and I can attest to how fast the oil can pump out when that line breaks! I was standing next to his LH fender when we started it up one day, and the engine was already hot. I felt my left leg get REALLY WARM FAST, looked down, and saw a solid stream of oil squirting straight through one of the gills in the fender. Needless to say, my blue jeans were worse for the wear, soaked all the way down! I think he had the engine revving about 3K when it blew...but it WAS plastic!!...Craig

[Joe L.]

Re: Oil Pressure Line --68 Corvette 327

Kurt----

The original oil pressure line for your car was black nylon plastic. It was GM #3906192, which was discontinued quite a few years ago. It's easily available in reproduction, though. The 90 degree brass fitting on the rear of the oil gauge is not easily available in reproduction, so make sure that you don't damage yours.

[Ralph E.]

Re: Oil Pressure Line --68 Corvette 327

Kurt, Without a doubt the line was NOT Copper. I was the original owner of a 1968 427/435 and I had to replace that line in 1970. The oil leaked into the interior and made a real mess.