1872 Oil Pressure Switch

[J-Mech]

Originally Posted by inspectorudy

When I went to buy a new sending unit from the auto parts store I would always ask positive or negative ground. None of the new parts had this listed on the part box and unless you have an actual part number they cannot answer that question. It does make a difference.

They don't have a diode in them, what makes you think there is a difference? I've ordered a million sending units for lots of different applications, and ground reference was never a problem. Positive, or negative.

[J-Mech]

Originally Posted by Mike McKown

Some later engines used a larger sender that resembled a very small mushroon can.

It's good to clarify, but this is the one I was referring to. The OP talked about his chevy from a few years ago...... I wanted to make sure that he knew which sending unit he was talking about. I didn't think there was any thought of going back as far as a Corvair. Either way, you are correct!

[FrankF3]

inspectorudy, I like your idea of relocating the sending unit by the oil filter. If heat is indeed the enemy to these switches, then I would think it would be much cooler by having it near the filter and not where the cooling air has just passed over the cylinders cooling them.

[inspectorudy]

Frank, that's not the sending unit but only the "T" that was required to insert the oil line with the pressure to the gauge.

[FrankF3]

I was thinking to follow your lead put in a "T" and re-locate the oil pressure switch next to the oil filter and have it in a cooler place. I would put a plug in the original location of the switch.

[inspectorudy]

I am still using the OEM pressure switch that came on my 1811 with no issues. I am not sure that the switch really needs to be in a cooler location since almost all PS are on engine blocks. I was not real happy with using the plastic tubing that came with the gauge so I wrapped it in a small diameter wire loom and have had no issues with it since.

[Darrell]

Instead of the nylon tube you may want to go with steel braided line or the gauge companies sell a roll of copper tubing for oil gauges.

Here is a link for some , but you can get it about anywhere.

http://www.amazon.com/Equus-9901-Cop...+copper+tubing

[inspectorudy]

I agree with you Darrel but the plastic came with the gauge and it has held up for almost three years. There really isn't much to damage it and the heat in that area is nothing like a big block V 8 next to a set of red hot headers.