CMP GM Dash Oil Pressure thread size?

[Bruce Parker (RIP)]

I got ten Weatherhead Eaton 6100X2 fittings today and they fit the back of the oil pressure gauge perfectly. Looking at the bevels on the male and female ends screwing in the fitting could operate as a compression fitting on the 1/8" tubing (or if not perhaps a flare may be required).

As to Rob's thought that the gauges for 216 and 270 engines may have different numbers and different pressures he may be right. The gauge I have marked for 30 pounds has the numbers 1506373 and 1506375 on it and the one in the Fox parts book is 1506377, presumably matching the 80 pound upper range painted on the instrument cluster glass. Looking at the 30 pound gauge guts I don't think there would be any damage if it was subjected to higher pressure. You just wouldn't know what the pressure was if it read over 30.

[Colin Alford]

Bruce,

I don’t have access to any Fox or Otter manuals but I do have access to C60X manuals.

When Rob posed the question of different pressures/gauges between the 216 and 270 engines, I had a look to see what I could find.

According to MB-C2 the early instrument cluster was graduated 0-15-30 for the 216 engine, and the oil pump was capable of producing 14 psi at 2000 rpm. Various Chev parts lists (Other than C60X) list the correct oil pressure gauge as 1506092.

According to M660-C1 the early instrument cluster was graduated 0-40-80 for the 270 engine, and the oil pump was capable of producing 35-40 psi at 1000 rpm. C60X-04 parts list shows oil pressure gauges 1506379 ( early with red pointer) and 1506377 (later with white pointer) which is also the same number you quoted from the Fox parts list.

If we disregard the 0 and 30 in the upper corners of your gauge, the part number seems to be much closer to the 0-80 gauges for the 270 engines than it is to the part number for the 216 engines.

Perhaps a test is in order to determine the actual range.

When the switch was made to individual gauges, both 216 and 279 engined vehicles used the same round gauge with part number 1506359. I presume the gauge had sufficient range to accommodate both types of engine.

[Bruce Parker (RIP)]

Thanks Colin, that's a ton of research and very helpful. You may be right about the Fox gauge given the number ranges. The cluster and gauge was in a NOS Fox dash and didn't looked messed with (for instance, the temp gauge was electric and had the instrument cluster been civilian or from a 216 Chev it would have been mechanical).

Originally Posted by Colin Alford

Bruce,

I don’t have access to any Fox or Otter manuals but I do have access to C60X manuals.

When Rob posed the question of different pressures/gauges between the 216 and 270 engines, I had a look to see what I could find.

According to MB-C2 the early instrument cluster was graduated 0-15-30 for the 216 engine, and the oil pump was capable of producing 14 psi at 2000 rpm. Various Chev parts lists (Other than C60X) list the correct oil pressure gauge as 1506092.

According to M660-C1 the early instrument cluster was graduated 0-40-80 for the 270 engine, and the oil pump was capable of producing 35-40 psi at 1000 rpm. C60X-04 parts list shows oil pressure gauges 1506379 ( early with red pointer) and 1506377 (later with white pointer) which is also the same number you quoted from the Fox parts list.

If we disregard the 0 and 30 in the upper corners of your gauge, the part number seems to be much closer to the 0-80 gauges for the 270 engines than it is to the part number for the 216 engines.

Perhaps a test is in order to determine the actual range.

When the switch was made to individual gauges, both 216 and 279 engined vehicles used the same round gauge with part number 1506359. I presume the gauge had sufficient range to accommodate both types of engine.

[Jordan Baker]

Here is the information for the Otter oil gauge.

[Bruce Parker (RIP)]

Originally Posted by Jordan Baker

Here is the information for the Otter oil gauge.

I bet the Otter and Fox gauge not only adjusted for pressure but allowed for a larger diameter line. Jordan, is the Otter line 3/16" or 1/4"?

[Colin Alford]

Bruce/Jordan,

I have done some more reading.

Oil pressure gauge pipes and fittings can be found at group number 1.519 in the Chev/GM parts lists.

Attached are two examples of the listings for 216 engined vehicles.

Pipe Assy 592818 started to be used upon the transition to individual round gauges.

The other tubing, union and nipple were used with the early instrument cluster.

The mentioned “Tubing unit” seems to be a parts listing of bulk coils of tubing for workshops. ( image attached)

Info regarding C60X to follow.

[Colin Alford]

While the listings for the 216 engined CMPs were easy to follow, the listings for C60X are not.

C60X-01 (October ‘42) lists 1/4” (upper) and 3/16” (lower) tubing. None of the listed fittings are the same as those for 216 engined CMPs.

C60X-04 ( January ‘45) lists 1/8” tubing, but the other fittings have the same part numbers as those for the larger tubing (a mistake?)

I am not sure what conclusions to draw, but please have a look at group 1.519 in your Fox and Otter parts lists.