Pressure dampening over a certain limit, so's to not damage the gauge movement when/if it exceeds some pre-determined point, I'd guess ~80 psi on that gauge. Your last comment could apply also... . Marcus...
This is the original dash insert and gauges for my 1932 Oldsmobile. They have bee cleaned only, not restored.
Most excellent Eelco score! Ironically, I just bought that vacuum & amps that Nick the Bandit listed here, which helped fill in the missing holes in my set that I've been collecting for quite a while. Yes, he is a bandit (haha), but you sure don't see these things come up for sale very often. I have a working oil temp, the supercharger gauge & an oil pressure. You didn't get an extra fuel pressure, did you? By the way, I've seen another version of the supercharger gauge, where the Eelco logo was above the two rivets. Yours is the first one I've seen like mine. Did you notice that the bezel on it is different than the others? I wonder if there's a water temp out there that survived?
How does the fuel pressure gauge work? Mine is directly connected to the fuel line, which tends to be considered a no-no.
yup, hooks to a fuel line. I think that you are supposed to mount them outside the passenger compartment
I should be the last one trying to explain how anything mechanical works, but essentially the fuel in a running car exerts pressure via a fuel line into a Bourdon Tube (inside the gauge), which in turn flexes & causes the needle to move via a small mechanical system of levers or gears. The oil pressure essentially works the same, as does the water & oil temp, only there the gas (like ether) in the line expands from the heat, creating the pressure to flex the Bourdon Tube. What I've never been able to figure out is whether the oil or gas actually goes into the Bourdon Tube or if its just air pressure (coming from the gas or oil) that goes into the Bourdon Tube. If it's the former, then I can see why you wouldn't want gasoline in a gauge in your dashboard....especially next to a cigarette lighter. Am I missing something? .
And a beauty it is! Remember that there are certain old folks on this site that might be in a certain time period where they might be starting to contemplate one last wish.
WOW!! @Moriarity you hit the mother load of eelco's!! Those are great and you have the original boxes, too! Damn, the eelco's are so difficult to find, you rarely...if ever..see them come up for sale! We know you will give them a great home. And great job to Greg @fleetside66 on your recent eelco finds. Thank you Mark and Greg for sharing your collection with the rest of us. Fleetside, I would argue that you're a stealthy collector Right when I think I have a handle on all your goodies you pull out all kinds of new stuff. I gotta say watching you guys makes me feel sssoooo much better about my gauge collecting problem, LOL! Yes, @Beanscoot as Moriority stated your fuel pressure gauge is typically plumbed in-line in the fuel line and should be in your engine compartment. My fuel pressure gauge is plumbed in-line in the fuel line between the mechanical fuel pump and carb (sits up near the valve cover) Looking at Fleetsides schematic I gotta tell ya, I've had the unpleasant task of lining up the pinion gear and sector link gear so a gauge will read correctly and that was not a fun project.
I imagine there is always going to be some air trapped between the fluid and the gage unless there is a leak in the gage or fittings, this is where it would be a problem with a fuel pressure gage in the passenger compartment. Phil
I'm tending to agree with you on that, Phil. I think it's the same as with an old boat speedometer, where I believe the water flowing into a (Pitot) tube creates air pressure, which acts on the Bourdon tube to move the needle. Moon used to make a really cool speedo very early on, but you couldn't use it on a car (obviously) because it worked on a different principle. Also, because of the nature of how they worked, I noticed that the lower speed graduations on the gauge face were spaced closer together than the ones at the mid & high range. And, obviously, there was no water intrusion into the gauge itself. That being said, I have noticed some of oil pressure gauges that have a film of oil under the lens. I guess, for the most part, the air trapped in the line will not let the liquid past it, probably because the pressure is relatively low. If the pressure was high, I'd think that the air would mix with the liquid at some point. It seems this is one of those things you really can't Google.
Initially there is air in the Bourdon tube, but over time it is replaced with the liquid. With my fuel gauge I can tell that happens as the gauge needle starts to jump around a lot since there's no more damping by an air pocket. When this happens I just disconnect the gauge and blow the line clear, and the needle moves smoothly until the air is "consumed" again.
My boat has one of those Moon speedometers. And here’s a SW marine speedo showing the connection for the tube
Very interesting the way the increments expand as the speed rises. I never could fathom why Dean Moon didn't commission a car speedometer when he brought out the smaller car gauges. U.S Gauge Co. made the small ones (pressure, temp, vacuum, etc.) & Jones-Motorola made the big tach, but no speedometer.
I wondered the same about the car speedometers. I have a couple of Jones Motrola moon tachs. Should probably put one in my boat...
The Jalopy Journal
