Oil temp sending unit size

[2eighTZ4me]

I have AutoMeter Ultra Light gauges. The sending unit I have for both water temp and oil temp measures .567" (roughly) diameter at 1 3/4" long. I am trying to order an inline oil temp gauge adapter from Pegasus Racing, such that I can just screw the sensor in and get readings from the line. The water unit actually screws into the t-stat housing fine. It is the same size as the oil sending unit. (Sensors look identical). I have been researching on Summit's website and only can seem to find 3/8" and 1/2" adapters. Can someone confirm the size I need to get, as .567" comes out to roughly 9/16" and I don't see that listed anywhere.

 

Pegasus racing recommends that if I'm using AutoMeter gauges, that I will need a 5/8 - 18 adapter, yet 5/8" comes out to .625". Am I measuring wrong? I measured the threaded part OD in between the threads.

[darom]

The source mentions the size:

http://datsunzgarage.com/rebuild/

 

"... the correct thread for the oil sensor hole on the passenger side of the block is 1/8" -18 NPT (National Pipe Thread)."

 

My 280z 1976 block had a British Pipe Thread (BPT) oil adapter. I ordered an Autometer sender/gauge and had to find an inline adapter BPT male to national pipe thread female for the Autometer sender.

[2eighTZ4me]

That's the pressure sender - not temperature. Already got the pressure fitting taken care of and plumbed. I figured it out though. I was indeed measuring wrong. I needed to measure at the crown of the threads, not in between. Pegasus was correct, for an AutoMeter TEMP sending gauge, the size is 5/8 x 18.