The mail man delivered my parts today, a BSPP female tee, a BSPP close nipple and a BSWPP to NPT adaptor. I bought them from Discount Hydraulics. About $21 + shipping.
I removed the gauge from the dash and ran jumper wires from the connections to the wiring harness. As Dennis states you remove the two cork plugs and see two slots with which to adjust the needle position. The one nearest the gauge light adjusts the high reading the other adjusts the zero setting. You don’t rotate the slots like screw heads, you push them to one side or the other.
With the engine running so I could observe the mechanical gauge I adjusted the high reading with a small screwdriver pushing the slot, to increase what the gauge shows you’d push it to the reader’s left in the above photo. Now with the engine running the Smiths and mechanical gauge agree, more of less.
The final task is to adjust the zero reading. Moving the high reading slot affects the zero reading so you need to push that slot to the slot to the reader’s right to move the needle to zero.
Ahh, pushing thick honey through its veins. I need to try this one day soon too. Mines been showing 65 cold and I am dubious! Glad it adjusts just like the other ones do.
It seems I have read, over different forum threads, owners have reported various engine oil pressure readings, varying from 20’s to 80’s, and more . I tried to look up the spec. I could find one spec of 40 psi at 3000 rpm hot, but it does not say if that is a minimum, maximum, or an average. One manual states 40 psi at 3000 rpm hot maximum. I found one place the relief valve is 42 psi. Do we know what the oil pressure is that we “should” have? After all, not only do we not desire to have low oil pressure, too high oil pressure would not be desirable either.
Tom
Morning John, good write up and well photo’d. I did the same thing with my Ser 2 a few years back and with the aid of a brass “T” on the oil filter I plumbed in a SW along with the electronic sensor. The SW is located just below the dash next to my left radio speaker and is lit as well. All good.
However, the only addendum to your missive would be to dump the Pex line in favor of 1/8" copper.
I did, and as Erica mentioned, "AHH all that thick oil pulsing through on cold startups’. Less chance for mischief, particularly if a Pex restraining tie breaks allowing the line to drift near something hot.
Best regards, Brian / Mytype
Hi John, this is good info to get in the archive… I did something similar with air pressure on the sender and I was surprised at how well I was able to dial it in by adjusting the high and low adjusters on the gauge. Will you be installing the mechanical gauge permanently?
Anthony
No, it did it’s bit and now it’s back in the box, along with the Tee, nipple and adapter. That’s why I wasn’t worried about the Pex line. A secondary gauge and associated plumbing and fittings represent additional potential leakage points.
I did preliminary tests with an air compressor and jumper wires to the car’s wiring harness. Engine off obviously. I could have adjusted it then, but it was suggested that the battery voltage is different with the car running and that might affect the adjustment. So I waited. Turns out the differences between the two gauge readings were the same with the engine running or stopped, so I could have adjusted it off of the compressor.
EDIT:
Something else I observed. There are occasionally concerns about t he length of time it takes for the Smiths gauge to show pressure, the logical concern being insufficient OP for the first few engine revolutions. I noted that the mechanical gauge consistently registered oil pressure almost immediately while the Smith’s gauge was still pegged at zero.
Thanks John. I did not remember the gauge was adjustable. I got the T piece from Merlin Motorsports and a mechanical gauge that will screw directly into it. I too worried about another place for oil leaks if I left it installed long term so I will try your method to calibrate and check for accuracy occasionally.
The problem with copper is having to deal with it if you need to take the gauge out (or the section of dash it’s mounted in). I always sweat bullets when I have to take a dash out with a copper O/P line. Same goes for ether bulb temp gauges.
Not period for a classic car.
At the end of the day, Stainless flex is just plastic with a mantle - if heat or aging are the problem with plastic, then they still are when you cover it in braid (plus you make it impossible to inspect visually).
I’ve never actually had a copper line break, but when I’m lying in the footwell of a car more expensive than my home, up to my elbows in sharp edges I’m always wondering “Will this be the one?”.
When I take a gauge out I also remove the distributor rotor and keep it with the gauge. When I was young I stupidly started a car after I’d removed the oil gauge… once.
I wouldn’t go that far, but if one can easily make something more accurate, why not do it.
