Responsiveness of oil pressure gauge in 73 240z?

[lombrozo]

My oil pressure gauge seems to say the right things, but slowly. I have not replaced the sender. I am wondering what the normal expectation is?

I can rev up the motor and it takes a few seconds for the gauge to get to 2/3 of scale. Is this typical, is it a normal sender failure. or a gauge failure?

73 240Z, 72 SUs, Pertronix, Racer Brown 280 cam, big alternator.

[Ramses]

If you want it to respond like your tack, then it wont. I believe that the response that your seeing is typical. My '73 has a pressure of about 1/4 at idle and then goes up to about 2/3 while driving. I have not looked at it while accelerating, to busy driving.

[dimsum]

My '73 has a pressure of about 1/4 at idle and then goes up to about 2/3 while driving. I have not looked at it while accelerating, to busy driving.

Is it normal for the stock oil pressure gauge to drop to 1/4 to 1/2 during idle, and then increase back up to 2/3 to 3/4 during normal driving? That's what mine is doing, and I was worried that I was losing too much oil pressure.

[Force Fed]

Sounds right, my '72 is the same. They use electrical sending units, which are usually slower to respond than a mechanical gauge. 10 psi at idle is plenty, and probably about what most used engines have, so a 1/4 gauge is normal.

[DougN]

Sounds about right. If you want to see a higher pressure reading on your guage, you can replace your sender with one from a roadster, as those will give you a higher reading on your guage. As long as the guage is not at zero, you are fine.

[dimsum]

Thanks for the response, guys. I haven't had my Z for too long, and I had just completed an oil change. When I saw the pressure drop so much while sitting at a light, I kind of freaked and thought I did something wrong. I'm glad to find out that it is normal.

[beandip]

Realize with these gages, is that they are merely indicating pressure. Depending on the setting on your gage will depend on where the needle is at idle or what ever. My gage was showing with a warmed engine at idle about 1/8" up from zero, and above midway while driving at about 2K. I bought a cheep mechanical gage for about $15.00 and installed it where the sender had been mounted, and put the gage in by the shifter where I could see it while driving. At Idle I have 25psi and at 2K 50psi. With the engine room temp the pressure is at 70psi where is supposed to be with the relief by pass working properly. For my peace of mind the $15.00 was a good investment. So now I know what the pressure is when I look at the gage . I used the mechanical unit only for testing.

[Poindexter]

Is there any way to piggy-back both the mechanical and electrical oil pressure gauges? I don't want to lose a functional dash gauge, but I wouldn't mind a pod of 3 smaller, more accurate gauges, on top of the ash tray, of say volt, oil press and something else, tbd.