External Oil Pressure Test Gauge

Hi,

I would like to purchase an oil pressure test gauge to use on my 308. Where does the gauge fitting screw into? Is there supposed to be a fitting on the sending unit?

Thank You,

Anthony

I think the mechanical guage goes in the same threaded hole as the oil pressure sender comes out of.

yes, I realized after I wrote this.....!

I am assuming the sender simply unscrews?

Thanks again,

Anthony

Anthony,

I did the same for my 355. My biggest problem was getting a crossover to go from metric to the standard thread that most oil gauges have that you buy from local shops.

Regards,

Pete

If you guys are just looking for a temporary way to test/verify the oil pressure, here's the hot set-up.

http://www.waekon.com/PS/catalog/dr05.html

I have this kit....It came with many, many adapters and fits virtually everything I've ever worked on. If the kit doesn't have the adapter you need, they'll make you one for free!

About $100...

Regards,
David

Hi,

Does anyone know what the 308's sender unit has for threads, M18 x 1 ?

I have a gauge, but need a female 1/8 NPT to male 18M ? adapter....

Thanks,

Anthony

I think they are M18.

Don't take a chance .. take it with you when you shop for the crossover. In Houston I found 1 shop that wanted $36 for the crossover ..I found another who gave me another brand as a 'demo'. You need a speciality nut/bolt/thread shop. M18 is a big metric size.

As i have spent a bit of time with the oil sender, in studying th orifice size as it relates to gauge movement, I would point out that the inside is hollow. While I dont at the moment know how deep, it may very well be enough to tap an 1/8" NPT on one of the flats, thus having a hand place to put the lines. The wrench I used for the many on and offs is a "reworked" 22mm, and it sure makes life easier. BTW: I found that opening up the small hole or dampening oriface in the end of the sender to .062" really made the dash guage react much quicker, yet it wasn't so large as to cause gauge flutter (the reson for the small hole) Flutter may be one thing you will encounter if there is no drag on the oil between the gauge and the motor. For starting neew motors, I use a separate micromessh scren type filter, and ithas a gauge,. The first one I tied flipped around so wildly it could not be read. I had to use a liquid filled gauge to get a stable readying. OH yeah, STAY AWAY from those cheap plastic lines!
HTH
Kermit

Thanks for the info, Matt. What I am trying to do is to just measure my oil pressure with an accurate test gauge and I am not sure of the threads (per inch) to use as my adapter fitting -I have not removed the sender just yet. (I think the diameter is 18mm?)

Thanks,

Anthony

Anthony, it is an 18x1.25mm.
Here is a pic of a test fitting I welded together out of a nut, and an air fitting. I plug in a trusted (known to be accurate)regulator, and if both the air gauge and the dash say 75 lbs, I can be fairly sure it is on the money. Works good in low pressure as well as high.
HTH
Kermit