So I bought a kit with three meters in one for under the dash. The temp gauge is now working well, and I'm moving on to the oil-pressure gauge now.

I'm wondering though about how effect this thing can be? The kit includes this little plastic tube to connect from the sensor to the interior gauge unit and the instructs say nothing about bleeding the unit to fill the little tube up with oil. Do you just have air in it? This seems like it would give a pretty inacurate reading, as a gas (air) left in that tube would be comressible. Perhaps somebody could explain how this is a normal set up and is an accurate way to get a pressure reading?

Thanks.

This is a perfectly normal setup. Compression of the air in the line is not a problem... the air is simply being pressurized to the same level (in psi) as the oil that's compresssing it.
--

Gary L - 1971 142E ITB racer, 73 1800ES, 02 S60 T5
BlueBrick Racing

It's quite normal - what air there is, is compressed of course, and the gauge will be accurate - as far as it's calibration can be anyhow.
I'd advise using copper tubing, and placing a six inch diameter loop as the tube passes into the firewall. The plastic tubing will get brittle over time and snap off near the engine fitting.

Yes, I wasn't too pleased to find plastic tubing to work with. Where do you think I could find copper tubing that would work and fit into the little fittings at each end? The look like kinch/compression type end sealing things. Do you thing changing the diameter of the tubing could effect the reading?

I'll probably have to content myself that the gauage is not going to be all that accurate. At least it would tell me of catastrophic oil-loss though.

Does anybody use a gauge that they feel is quite accurate? If so... do you notic e the reading of PSI going down as your run lower on oil and need to add more oil to your system?

every time the engine stops if the gauge is higher than the connection to the block the oil drains back to the pan.i use an adapter fitting at the block 1/8 pipe to 3an then a 3an hose to a t fitting which is from an mgb which has an oil pressure sensor in it(in out sensor) for the light.then the copper line from t to gauge all from an mgb readily available from the usual suspects.pressure per rpm is the important reading not is 50psi or 45psi the correct reading.you could use a 3an hose from block fitting to gauge fitting if desirable.

Most of them that really have numbers are pretty accurate and pressure is only
affected by tubing size when there is flow involved. The amount of flow to activate
an oil pressure gauge is so small that you could have a VERY small line and it would
work fine.

The idiot (yellow) light is pretty good to tell you about catastrophic oil loss
and does not require close reading of numbers. Be sure and leave it hooked up.
Use a tee pipe fitting if necessary.

Oil pressure depends on several things, one of which is usually NOT oil level unless it gets below the level of the pump pickup.
The things are: tightness of the pump, effective volume of the pump per revolution,
pump speed, leaks in the oil lines, resistance to flow in the filter, bearing clearances,
temperature of the oil and parts being lubricated, and viscosity of the oil (which changes some with temperature).
--
George Downs, Bartlesville, Heart of the USA!

OK. All the above info is helpful, so thanks. I probably don't pay enough attention to that little dash-light I know. I've only seen it come on very infrequently -- say on a very, very hot day just after a very long push and I rev down to a stop sign. I think the oil is so hot that it would just flicker briefly for a time.

I was just thinking to myself that I should look into hooking up a little buzzer in-line with the dash light so that I would have an audible signal to pay attention if something goes wrong. It wouldn't seem like that would be a hard thing to figure out.

How about a seat-belt buzzer out of an old 240....
That is about as obnoxious as any I know.
--
George Downs, Bartlesville, Heart of the USA!