As I start looking at laying out my next project, I am trying to decide which way to go with a couple of after market gauge. This is for my 68 Road Runner. I like the idea of electrical oil pressure gauge as its a bit easier to run a couple of wires than a tube. Does anyone have experience using electric? Would a decent gauge like an Autometer have fast enough response?

Just curious what others may be doing.

For my new GTX build I went with electric for everything but the oil pressure. Just could not pull the trigger on electrical for such an important function.

Quality electric gauges are expensive. I paid a lot for the gauges.

Another vote for a mechanical

The only worry with a mech (for me) is if it ever leaks onto my wiring/carpet (take extra care with the initial install). I would think a quality electrical could be had.

RR .... have you ever EVEN HEARD of a tube or connection leaking with a mech gauge ?

To answer your Q. In all my years I have only seen one that had a slight drip.

I have a gauge made by Marshall Instruments. It is very fast acting, but the best part is it has programable hi and low limits warnings, which can also be used to trigger a remote warning light to get you attention.

Tube fracture or fitting failure ?

No inherent difference is accuracy, response etc. That will vary by price in either case. Find me a mechanical oil pressure gauge in any modern factory car.....including performance cars, supercars, boosted cars. No issue with using one, but price might be the only possible reason I can think of.

I use mechanical as I like having a "live" gauge. I'm seen electrical ones act up and oil pressure is pretty important when it comes to an engine. Every mech gauge I've bought has come with the plastic tubing which is not allowed for a race car. I've had the copper line crack on me twice in my time. Both times where the line would be in the fitting at the engine. After the 2nd time I changed over to a -3an braided line, not more cracked lines for me. Not all gauges are compatible with braided lines. I had cheaper gauges for years, but ended up purchasing an Autometer oil pressure gauge when I did the braided line setup.

There is no problem using a QUALITY electric gage. As mentioned above, virtually all auto manufacturers use electric ones.

One thing that I always do with my oil pressure gage is to "T" the block port and put both the gage pressure sender and an idiot light sender in it. The idiot light sender goes to a small red blinking LED that can be put in a lot of different places in front of the driver.

With a large selection of trigger points available on the light senders, you can set on-point of the light where ever you want. I usually set mine somewhere around 10lbs.

The warning light pieces can be done for $15 or so at any auto supply.

I've used the braided stainless line in my other car. It was a bit more difficult to route around stuff. Id line to get the gauge up under the dash pad over where the clock would be. So not a lot of room to make bends with thicker braided line. I could probably fish a pre-bent 1/8" stainless hard line for a short distance, then connect flexible stainless under dash and through firewall to engine.
But a couple of wires would be much easier. And I do like the ability to have a low or hi limit alarm. Costs aside, if it has the functionality I want, Ill buy it.

Thanks all.

I had an electric oil pressure gauge in mine and when a couple of the other electric gauges went bad (Cyberdyne)
I swapped it out for a mechanical one even though routing the hard line was a pita...
One thing to watch is you have to ground the gauges to the engine and not the dash...I turned the radio up and the oil pressure dropped and water temperature spiked...grounding to the engine corrected that...
1st pic is the Cyberdyne gauges...
2nd is the new Stewart Warner Green Line...

I ain't for sure (many years ago), it was a slight drip right behind the brass fitting at the gauge. X2 what Dave said, T into the port & add (or keep) an idiot light & use a sender that turns on higher than the OE ones, 15 maybe 20 psi.

I like mechanical. I used copper tubing when I did my truck years ago with no problems. I personally like Autometer gages. In my 2001 Cummins dually I used air brake tubing with push lock connectors. I also used needle valves under the hood so if there are any leaks I can close the valve at the source.

If I was driving a choo choo with a boiler then a mechanical gauge might make sense.

Otherwise it doesn't. Modern electrical gauges are lights ahead of mechanical ones.

That's exactly what hit me earlier when this thread got me thinking which was to add a valve at the eng port if there ever was an issue. I ain't sure what a needle valve is but I will Google it & add one on my next build if I use a mech gauge.

In YOUR opinion. I stick with steam gauges..
https://www.vansaircraft.com/cgi-bin/sto...;product=va-128

yay, you found a fitting, how fitting.

Pretty much anything not stone aged technology, including Lycoming there, uses electrical gauges for a reason. They are more precise, more accurate, more flexible and more responsive.

Short sweep Autometer electric gauges. Been running them for years without issue. I did have a cheap mechanical piss all over my shoes once. Had to drive home one-handed while I was crimping the line with a pair of pliers.

I only use a mechanical for ease of setup when priming a new engine or something. My Hemi runs solely off electronic sensors, good enough for me.

I've lost more then 2 mechanical oil pressure gauge lines before. One was plastic, the other one was copper. I still have a mechanical OP gauge to put on stuff that came with just the lights to see what the pressure is.

The new gauges I bought for my truck are full electrical Speed Hut Gauges www.speedhut.com and they came with the gauge, the sending unit, and the wires to the sending unit. Their gauges are made to order in the USA, it takes about a month after you order before you get them. Not cheap, but nice stuff. Gene

I totally agree with the popular response, electric.

Running engine oil into the passenger compartment is not a good idea, we don't do it with fuel, no need to do it with pressurized engine oil.

Roadrunner's question from the original post. "Is it fast enough?" While this is a valid question and the nod does go to mechanical but why is that important. If an electric oil pressure gauge needle is not as responsive as a mechanical vacuum gauge is it any better or worse? I do not feel that an oil pressure gauge that has a dampened needle action is any less of a gauge.

I'm in the process of taking the gauges out of my car. I switched to EFI and the sensors plug into the EFI computer. So I can get all the data on the screen and I can data log it. I'll have a big pile of Autometer guages to put up for sale in the future.........

The electric gauges used to be inferior, however modern ones are as good as mechanicals IMO. I have had the mechanical oil pressure gauge leak. Fortunately I had it mounted to my steering column so the oil puddle dripped down onto my floor mat. If I had it mounted in my dash that mess would have been a nightmare.

Mechanical, but use a copper line, not the supplied plastic one for sure

I've always preferred mechanical gauges for the simple reason that they have a 270 degree sweep (the Auto Meter ones I like, anyway) whereas the electrical ones have a smaller arc. Some as low as 90 degrees. The bigger scale can be read more quickly and accurately.

And for slowly and frequently changing data like a speedo, tach or oil pressure, I've always preferred an analog (needle) to a digital gauge. Those constantly changing, blinking numbers would drive me nuts. Picked up that habit on the workbench (got my BSEE 37 years ago).

Never had an oil gauge line leak, but then I haven't built as many cars as a lot of people here. Either use the soft copper 1/8" line, or spring for a 3AN Teflon line and never worry about it again.

Either one for me. I have a 500" bb in a volare now, and upgraded the hose to aftermarket dash gauge with braided hose and AN fittings. Not dripping on my feet yet. I had a 68 impala super sport many moons ago, and it had a factory copper line to dash. So mostly, worst issue with electric gauge is wrong sender getting mixed into project vehicles.

Modern electrical gauges have a 270 degree sweep, or better.

Autometer has more than 300 different electrical guages that have 270 degrees of sweep, or more.

Old Chestnut

as for oil pressure lines, i have used tiny hydraulic hoses. way better than that crappy plastic line [which, in my opinion, is good only for vacuum use] and way cheaper than braided an hose. the drawback to this is weight and possible routing issues.

I’ve yet to hear of an Autometer electronic oil gage dying or anyone losing their engine because of a failure. I ditched the 50 year old aftermarket technology.

I'm not going to argue with someone who has a preference for a mechanical gauge, but if you want a factual reason to use one, none of those raised hold water. Again, there is absolutely no inherent issue with accuracy or responsiveness with electrical (got a tach in you daily driver? responsive enough? ...it's electrical).

Anecdotal evidence is just that and runs both ways, I'm sure we can find examples of people who died at a ripe old age after smoking 20 a day all their life, that has zero bearing on the facts that smoking is bad for you! Similarly, just because someone found a faulty electrical gauge, al that proves is their electrical gauge was faulty. same would apply to a faulty mech gauge.

If we were splitting hairs it wouldn't surprise me if mech gauges were actually less repeatable over a lifetime, but it's a moot point either way - both technologies are more than accurate, repeatable, responsive, reliable enough for what we need. Choose your poison, just don't do it for the wrong reason.

I like and will continue to use mechanical gauges.

Really? Do you run a cable-driven tach? Does your water temperature gauge have a long capillary tube to a bulb in the water outlet? And, how DOES a mechanical ammeter or voltmeter work? Where is your gas tank mounted so you can see the amount of float rod sticking out of the tank?

The only really mechanical gauges in most cars are the speedometers, and in newer cars they are electronic as well.

I once owned a car that had had a mechanical oil pressure gauge installed and yes, it dripped hot engine oil on my feet.
Mechanical pressure gauges are just as likely to be inaccurate as electronic gauges. Maybe even more. Take a pressure spike that exceeds the limits of the gauge. The Bourdon tube in a mechanical gauge may become permanently deformed and require, at a minimum, recalibration. The electronic gauge sender bottoms out and sends a big voltage to the meter, which hits the top limit and then comes back to normal, usually with nothing more than a bent needle on the gage, and they are rare.

I'm a mechanical engineer by training and philosophy, and I like mechanical things. But I will freely admit that there are some things that are just done better using electricity.

R.

That's cool. I'm glad we have options and live in a GREAT country where we can CHOOSE!

🍻 🍻 🍻

in the past, my preference for mechanical gauges was the 270 or so degree sweep action, while the electric's, at the time, were limited to 90 degrees or slightly less.
today, if i were buying a new set, i would more than likely, choose electric. lots to choose from in almost any font you desire [and then some], and are as accurate as can be, especially the ones that use stepper motors in their guts.
i also like electrics as you can use a single gauge to monitor more than one item, such as using a temperature gauge to monitor two [or more] places by simply toggling a switch.

How do you hook up a hydraulic or braided line to a generic oil pressure gauge that only has a fitting on the back for the nylon hose compression fitting cap? I have owned other mechanical gauges that have a different fitting, but it seems most only have the fitting for the nylon line.

I have been using the oil gauges with that small plastic line since the mid '70s and never had an issue.
Even one in a truck I've had for a few decades now and still use, with no leaks...

on those types, i used a brass female adapter that had an inside seat the shape of the furl used on the plastic line, and the other end was a male fitting to [i think it's called] JIC, or something like that.
got those fittings from the lab at work. i don't remember what they were used for originally.