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Autometer Gauges - Mechanical or Electrical?

Discussion in 'The Garage' started by Greg72, Mar 12, 2002.

  1. Greg72

    Greg72 "Might As Well..." Staff Member Super Moderator

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    I'm curious about the reasons why someone would choose a mechanical gauge over an electrical one. I noticed that Autometer offers a choice on many of their gauges.....especially "oil related" ones......(temp, pressure)

    It seems like a lot more hassle to plumb oil lines into the dash for a mechanical gauge.....so I'm wondering what the "payoff" is. Are they more accurate, or faster responding?

    Just ANOTHER thing I know nothing about, so I thought I'd ask the experts.....! /forums/images/icons/smile.gif
     
  2. K10ANDYKHAMNIC

    K10ANDYKHAMNIC 1/2 ton status

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    i bought the mech ones with the reasoning that if they broke u would know it and they might be more durable ... i dono check my pics page for pics of them in my truck.
     
  3. Triaged

    Triaged 1/2 ton status

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    The mech. gages have a broader sweep than the elec. ones do. Autometer just came out w/ a few "full sweep" elec. gages that sweep as much as a mech. but there arn't that many styles/types available yet.

    I would go w/ the "full sweep" elec gages for things like oil press. because I don't like the idea of running a oil line (plastic even) into the cab. Makes for a nice oil leak on your foot. Other than that mech. gages have less to go wrong and are cheeper.
     
  4. Ryan B.

    Ryan B. 3/4 ton status GMOTM Winner

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    Hey Greg-
    You mention plumbing oil lines into the dash for a mechanical gauge...
    Don't you have a mechanical oil pressure gauge in your dash now? I don't know bout you but I have a hard line that goes through the firewall to the back of the engine block for my stock mechanical gauge.

    Now about the Autometer gauges...
    I doubt it would be hard to make it work with that existing line, perhaps all you'd have to find is an adapter fitting?...
    In my camaro i have autometer mechanical liquid filled gauges, for the oil pressure, coolant temp, and fuel pressure.

    -For the oil pressure it isn't a hard line like in my blazer, it's braided steel hose with i think AN -4 fittings on the end. That hose would be cake to install for a gauge.

    -For the coolant temp, it is a pain to hook it up with the 6' long hard wire line... that is there's a bulb type sensor that goes into the manifold, up to the gauge and there is no way to disconnect it... I wanted to move my gauges and i ended up having to undo the sensor and feeding it all the way up through the dash, then relocate the gauges and run that hard line again.
    What is cool about those mechanical temp gauges is that after you turn off the key it always tells ya what the temp is.
    ...as a pose to electric gauges, as soon as you turn off the ignition and take the key out, the electric temp gauges stays "frozen" until you turn on the key again.
    Like when i take the key out of the ignition, i can sit there and watch the temp rise 10 degrees after i turn off the engine (and the cooling fan.)


    -For the mechanical fuel gauge, I still don't have it hooked up yet. It is Very Dangerous and illegal to plumb a gas line into the cab for a fuel pressure gauge! Duhh. You can have one on the outside like mounted right on the cowl, and it looks really cool too. right./forums/images/icons/shocked.gif
    To run that mechanical fuel pressure gauge, i have to hook up an isolator with a line from the fuel pressure regulator to the isolator... then a line with coolant in it from the other side of the isolator up into the cab and the mechanical fuel pressure gauge.

    Plus... wires are little more tempermental (sp?). How often do you hear about wacky electrical gauges or the wiring.. short to ground this, shorted or crossed wire that... With mechanical gauges it'll either be "dead on" or broken and not working.
    With electric gauges I believe that it is possible to have a little "excessive resistance" between the gauge and the sensor and that will throw your whole accuracy of the gauge reading off... exessive resistance = voltage drop = affected reading.



    I'm sure someone will correct me if i'm wrong on any of this.
    Hope this helps ya some.
    I'm sure there's more people around here that can chime in a few more things.
     
  5. Greg72

    Greg72 "Might As Well..." Staff Member Super Moderator

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    Thanks to everyone for the responses.....

    Now for the followup questions.....what is "full sweep"? Most of the gauges I see have what looks to be a range of motion for the needle of about 90-degrees.

    ......also, I've been debating over the 2-1/16" vs. 2-5/8" styles. It seems that the smaller ones become hard to read. The "tail" of the needle looks like it would block the "description" of the gauge function. On the larger one, everything appears to be more readable....but they're getting a bit large for in-dash installations! /forums/images/icons/smile.gif

    BTW -> This all came about after last weekend's wheeling trip. I don't think that "putting my hand on the trans hump" is a very accurate way to measure transmission temperature!!! It was certainly warmer than usual though...... /forums/images/icons/shocked.gif
     
  6. GMCLegacy

    GMCLegacy 1/2 ton status

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    i have full sweep mechanical auto meter guages in my '80, the needle move almost 270 degrees, it is easier to read, and gives you a more accurate reading.
     
  7. fortcollinsram

    fortcollinsram 1/2 ton status

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    In general, mechanical gauges are more accurate and are more "dynamic" (or faster responding, as you said). My roommate has a mech. boost gauge on his Cummins and an Electic Pyrometer and the boost gauge jumps up and down a lot faster then the EGT gauges does...I think electric is nice for the ease of installation and not having to worry about oil leaks and such...

    Chris
     

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