A thread sandwich.

I dispensed with both the clock & the oil temperature gauge, being neither interested in the time when I’m out, nor the fatuously inaccurate temperature figures & replaced them with something I am interested in, oil pressure plus an accurate temperature reading. To adapt these I bought a sandwich plate to go between the oil filter housing & the filter, assuming that the screw adaptors would be compatible, they are not! The closest the kit comes to being correct is the 20mm x 1.5 unit which screws into the filter although not an impressive fit, the internal thread wouldn’t even look at the filter housing. The thread form is 13/16” x 16 tpi & this on a car from the metric era, with no other imperial thread as far as I am aware. Fortunately I picked up a 13/16 tap & ten minutes later I was screwing it all together, the thread disparity between the oil filter & adaptor wasn’t significant enough to be a worry although I fitted a generous amount of PTFE tape to make the fit “more reassuring”. And as Ed China would say, Result.

OK here is my original thread. Gauge thread I also replaced the clock and oil temp gauges with a matching pair of temp and pressure.

I did spend some time with an infra red temperature gun and introduced several different resistors to match the temp gauge to real life temperatures. :lol:

Incidentally the sensor thread is 1/8 NPT, which changed to metric around 2000.

Thanks David. I started this caper by buying a couple of digital / analogue instruments to replace the old units, plumbing the senders into adaptors, taking the original senders M12x1.5 to two 1/8” tpi, dispensing with the OEM unit. The length of the adaptors & placing the temperature sender furthest away from the oil created a temperature gradient rendering the accuracy of the instrument an irrelevance. It was then that I went for the pancake type which caused the upset, I have subsequently given the new arrangement a good shaking down & find that both pressure & temperature accuracy are within claimed tolerances, the temperature being an order of magnitude better than original.