replacing gauges

[MPallock]

Gentlemen:

I am think of adding 2 gauges under the dash of my 54 commander to more closely monitor water temp and oil pressure in my new 259 motor.
Or are the existing 54 gauges accurate enough? If replacing them is a good idea, which gauges would you choose? The cars is still 6v pos gnd.
Thanks for your input: Mark

[Dick Steinkamp]

There are no numbers on the '54 oil pressure and water temp gauges, so it is hard to say how "accurate" they are.

If the water temp goes more than 3/4 scale, it's getting too hot. Generally it should run around half scale.

The oil pressure should also run half scale to 3/4 scale when off idle. 1/4 scale (maybe even lower) at idle. It will depend, of course, on the specific oil you are running, how warmed up the car is, and the ambient temp.

There are after market mechanical gauges made for both water temp and oil pressure, so 6V shouldn't be limiting if you really want to see actual numbers.

I wouldn't bother with duplicate gauges, but that's just me.

What I HAVE done is hook up "idiot lights" for both oil pressure and water temp (in addition to the gauges). I don't know of any 6V sending units, however, so you would have to hook up some sort of voltage drop to use available 12V units. It's tough to constantly monitor gauges. You could loose oil pressure or spike water temp while you are not looking at the gauges. A light would generally alert you to a problem before you noticed it on a gauge.

Dick Steinkamp
Bellingham, WA

[rockne10]

The oil pressure is mechanical. You could just separate the hose from the pipe above the engine and temporarily attach a metered gauge to see your pressure at idle. That will give you an idea of where that's at on your dash gauge. At hot idle, above 10 is sufficient; anything beyond that is icing.

Same ploy could be used with the temp gauge but you would either need a mechanical gauge, a 6-volt metered gauge or a 12-volt gauge with a voltage drop.

Once you know the numbers and how they correspond to your unmarked dash gauges you don't need the multiplicity.

[Lark Hunter]

Stock gauges are usually fairly accurate, in my opinion. To put some numbers to the readings: The oil pressure gauge reads in a linear manner from 0-80psi with
20-40-60@1/4-1/2-3/4 scale. The temperature is approximately 100 degrees when pegged on cold-170 in the middle-210 @3/4- 230 when pegged at the hot end of the scale. For whatever it is worth, the ammeter reads +or- 50amps, 25 amps bringing up the halfway point.

LH

[MPallock]

Great idea's:

I may temporily install a new oil and new water gauge for reference then apply the readings to the old gauges.

Thank you: Mark