Oil Pressure Gauge Supply Line

My 304 has the factory electric oil press gauge. I would like to install a good quality direct oil feed gauge. Finding a good quality gauge is no problem however the oil line kit supplied with most of them seem to be a poor quality nylon tube or some very skinny thin copper tubing, all very susceptible to damage from chafing vibration and hot exhaust manifold ect. Can any one suggest what type and where to find something much better quality. I was thinking maybe a small hydraulic line or some type of oil lines used for remote oil filter installations like on the F134 engines. The line would probably need 1/8 pipe fittings on both ends?

 

For the quality line your looking for I would use a -3AN Teflon core braided stainless line with -3AN to 1/8 npt adaptor.
Will look very nice and easy to make up or have made. Cost being of no consideration .mike

 

Summit Racing has premade hoses in various lengths that will work for this. I think I have -4AN on my Oil Gauge and -3AN on my Vacuum advance. saves time and money

 

I’ve had the copper line on my mechanical Autometer gauge for 25 plus years with no issues. It’s all about routing carefully. The SAME copper line, no replacements. Of course if you want to spend more money needlessly that’s none of my business.

 

did you leave a coil at the engine end to allow movement?

 

I think copper would be fine. I've used it without trouble.

The key is to allow some slack, but not much unsupported free movement. Repeated flexing causes copper to work-harden and become brittle.

 

Thanks for all your replies. I certainly give consideration to all of them. I am thinking I need the very best line I can get. I lost a heavy truck diesel engine from one of the small copper lines that failed right next to the engine block fitting. even though careful attention had been given to properly support it. I guess it just could not handle the diesel vibration. The cost of the best line I could buy would of been far less than 1 percent of the cost of that truck engine rebuild.

 

I run the -4AN from the engine to a bulkhead fitting on the firewall. Inside is the plastic line covered with small vacuum hose, supported well under the dash.

 

I have had good luck with the nylon lines in the Stewart-Warner installation kit. I put the whole length of line inside an equal length of rubber vacuum tubing, before securing the ends with the supplied nuts and ferrules. As mentioned, keep it away from the hot exhaust manifold.

Copper will fatigue and break after continued flexing. Same with aluminum. This is why airplane fuselages have a finite number of pressurization cycles before they are scrapped. Steel is unique in that it has a stress threshold under which no fatigue will accumulate. Whenever I've run copper lines for gauges, I've put a few coils of extra line between the engine and firewall, to distribute any stress along the coils.

 

A different option- I use a good quality (Auto Meter) electric gauge. It's very accurate and no worries about the line leaking.

 

I suppose I could go with an electric gauge, I just like the very quick gauge response with the engine RPM change of the mechanical gauges. on a side note I had an older diesel PU that I had added a salvaged key alert squalk box placed under the dash and wired to a idiot light sending unit along with the gauge.

 

x2

 

Nope but the line run is long enough to allow plenty of movement with no concentration of flex in one area to cause work hardening and fatigue.

 

I had 8 years ago a Willys WWII direct pressure gauge, put by my local specialist. Yes it is copper hose, but well protected. Other possibilities exist of course.
Obviously money is not involved, protecting the engine.
A friend of mine, good expert, on his VW Golf had fixed all sort of gauges !
Oil pressure, oil temperature, etc... That was interesting, mainly according to oil quality, temperature outside, temperature of the engine....

 

Upon inspecting the Spirit Of St. Louis. Lindbergh had the engineers cut each one of the copper oil lines remove a short section and then bridge the gap with flexible line. As he knew the long flights vibration could cause an Oil line to crack.

 

This is the route i took, works great