What are the graduations on the gauge

[ramairthree]

supposed to be? on a 74 rr

I just the an old sending unit put in, and the rights wires spliced together.
My reading is barely at the first hash mark under the PR.

At some point I will get the right kind of T plumbed in and run a real gauge, but this is what I got for now.

Thank your for any info.

 

[jessipup]

That's much like mine. I was reading only to the first mark and then going back half way to zero. I replaced the sending unit and it will run up to the second when cold and then fall back to the first. if I bring the revs up a bit it climbs again and stays there until I let it idle back down.
Now when it's good and warm and I come off the highway it will fall all the way to a little below half way to the first or a little less.But becausr it is stock equiptment and I really don't want any aftermarket guages hanging off the bottom of the dash.
I also would sure like to have some kind of approximate relation between the marks and the pressure they represent. I have a 318 stock with a little over 45000 on it, right now it has 10w-40 in it but I may put in a 15w-40 today and see if that brings up the pressure a bit. The test temps have been between 65 & 100F. In the old days here in texas I would just run a 20w-50 in everything.

Thoughts anyone?:thinker:

 

[YY1]

Isn't it obvious?

Not quite a third, a little above a half, and somewhere in the vicinity of 11/16, or 7/8.

Seriously, who decided that one? Maybe The built on Monday morning or Friday afternoon stigma applied to management decisions as well.

I would treat the area bounded by the three inner marks as the "operating range", with the far left as the minimum, the center as ideal, and the far right as maximum. Anything below the first mark would be unacceptably low, and anything above the third mark would be excessive.

 

[tpodwdog]

id just be happy it works!...all my gauges on my 70 RR ( when they do work)...read half. full tank of gas reads half....oil pressure should be 40 psi in a perfect world...mine reads 20...and so on and so forth. ANYONE GOT ANY IDEAS WHY IT DOES THAT?....im guessing a bad ground but i cant find it...i been all over that car !

 

[YY1]

I've had Mopar motors that carried 20 lbs at idle and went up to 80 at full throttle and others that carried 78 at idle and 80 at 1200 RPM (on an aftermarket mechanical gauge).

I'd put in a mech guage, at least temporarily, to verify.

I bought a parts store AutoMeter for $18 to do just that on both the cars I'm currently working on.

Shouldn't take more than 1/2 hour to swap the sender and find a temporary spot to set the guage (even under the hood).