Gauges

[Gaijin]

I’m looking to swap my analog Autometer gauges for Smith AC Cobra 8K tachometer, 180 mph (mechanical) speedometer, oil pressure, oil temperature, water temperature, fuel level and ammeter.

Will the Smith gauges use the same wirings as that of my installed Autometer gauges?

Will Smiths also be calibrated to read the same values?

[CraigS]

I have no specific knowledge of Smith's gauges but I doubt it. Usually gauges come w/ their matching sending units. RE; wiring, yes most likely the wiring will work out. Does your FFR have an ammeter currently? An ammeter may need it's own wiring even if you have one now. Over the years I have seen several different ways to make them work.

[gbranham]

Curious about using an ammeter gauge. I see the value in a voltmeter gauge, but ammeter? Not sure I understand the value in monitoring current. I assume maybe it's to measure an alternator's health/performance. Educate me!

Greg

[Mike.Bray]

Curious about using an ammeter gauge. I see the value in a voltmeter gauge, but ammeter? Not sure I understand the value in monitoring current. I assume maybe it's to measure an alternator's health/performance. Educate me!

Greg

I've always wondered that too. Weren't ammeters from the days of generators and carburetors?

[Jeff Kleiner]

Ammeters carry full battery amperage behind the dash...faulty wiring or ammeters and have burned down even more cars than glass fuel pressure gauges in the engine compartments have. If you're going to use it you best put a megafuse in line.

Jeff

[rich grsc]

I've always wondered that too. Weren't ammeters from the days of generators and carburetors?

Yes, when a generator maxed out at 30 amps. No way should you put an ammeter gauge on a modern alternator making 100 amp or more.....hello car fire

[Mike.Bray]

Yes, when a generator maxed out at 30 amps. No way should you put an ammeter gauge on a modern alternator making 100 amp or more.....hello car fire

I was just thinking that Rich, alternators can put out crazy amperage. The one on my Camaro is 160 amps.

[FLPBFoot]

In the marine industry, particularly on larger boats that have a DC side with large battery banks for house power, running refrigerators, etc, the control panels will typically have a voltmeter and an ammeter to monitor drain on the battery bank. Most I've seen use a shunt where current flows through the shunt plates and the ammeter displays the voltage drop across the shunt converting this drop into amps. This keeps the large high power DC cables where they belong and allows small wiring to come up to the electrical control panel of the vessel.

Agree that having one on our cars is not necessary but is someone wanted to, the calibrated shunt would be the way to go to keep the large high power cables in the engine compartment where it belongs.

[edwardb]

Airplanes use a shunt to measure current flow as well. Installed one on the firewall of my airplane build. Main power feed goes through it. Results in a very slight but precise voltage drop and current can be measured. Small gauge wires through the firewall to the instruments. Ohms law in action.

[MaxVmo]

Airplanes use a shunt to measure current flow as well. Installed one on the firewall of my airplane build. Main power feed goes through it. Results in a very slight but precise voltage drop and current can be measured. Small gauge wires through the firewall to the instruments. Ohms law in action.

Whatcha building edwardb? Buddy of mine is redoing a Long EZ project he picked up for a song.

Curious how many aviators we have here?

[Jim Doak]

I had Smiths gauges in my first build, including an ammeter; however, I wouldn't do it again. The oil pressure, coolant temperature and oil temperature gauges were mechanical, which required running a capillary tube from the temperature senders to the water and oil temperature gauges as well as an oil-filled tube from the oil pressure sender to the gauge. Also, I had to run a speedometer cable from the transmission to the gauge and get the correct, color-coded plastic gear for the output shaft to calibrate the gauge to read correctly. Kind of a pain.

Perhaps you can get non-mechanical Smiths gauges now?

[rich grsc]

Why would anyone want smith gauges?

[edwardb]

Whatcha building edwardb? Buddy of mine is redoing a Long EZ project he picked up for a song.

Curious how many aviators we have here?

I built a Sling TSi. It's done. At least as far as I could take it. Sold the ready to paint and assemble build to a gentleman also here in Michigan. He's been keeping me posted and is making good progress finishing it up. I'm not a pilot, but this was a lifelong dream. I did a couple of threads:

https://thefactoryfiveforum.com/showthread.php?45961-My-Journey-to-the-Next-Project-Sling-TSi-Build

https://thefactoryfiveforum.com/showthread.php?48654-My-Sling-TSi-Airplane-Build-Walkaround-Video

Also, mentioned in the first post of my Mk5 Roadster build:

https://thefactoryfiveforum.com/showthread.php?51545-EdwardB%92s-Mk5-30th-Anniversary-Build-More-Footboxes&p=583297&viewfull=1#post583297

[gbranham]

Why would anyone want smith gauges?

Because they're a glutton for punishment. Hah!

Greg

[StangRacer]

Smith's does now offer modern electronic gauges.

When I ordered mine, I opted for the volt gauge over the amp gauge along with the GPS speedometer... I kind of wish I had gone with the mechanical speedometer. I am using a Chevy S10 tailstock on my T5Z transmission to move the shifter. At the time I ordered the Smith's gauges I was not aware there is a fella on ebay that makes a bolt on sleeve to move the speedometer drive gear on the tails haft that allows one to adapt the Ford driven gear to the S10 location...

As far as how the wiring of the Smith's gauges compare to the Autometer I have not wired any Autometer gauges in 10+ years but I can't imagine it would be too difficult to change them over. The wiring directions that came with the Smith's gauges do call for each individual gauge to be fused.

[MaxVmo]

I built a Sling TSi. It's done. At least as far as I could take it. Sold the ready to paint and assemble build to a gentleman also here in Michigan. He's been keeping me posted and is making good progress finishing it up. I'm not a pilot, but this was a lifelong dream. I did a couple of threads:

https://thefactoryfiveforum.com/showthread.php?45961-My-Journey-to-the-Next-Project-Sling-TSi-Build

https://thefactoryfiveforum.com/showthread.php?48654-My-Sling-TSi-Airplane-Build-Walkaround-Video

Also, mentioned in the first post of my Mk5 Roadster build:

https://thefactoryfiveforum.com/showthread.php?51545-EdwardB%92s-Mk5-30th-Anniversary-Build-More-Footboxes&p=583297&viewfull=1#post583297

Great story! By the way, Nampa has a great aviation museum with an airworthy P-40 and other stuff. I had the airplane sickness since I was a kid as well. I tried for military aviation but had red/green color issues and in 1993 no waivers were being issued (crushed) so pursued the civilian path and now spend my workdays looking out the cockpit left seat window of a 737.

I’ve seen so many posts here with aviation connections, so got curious. Thanks for the read—brings back memories.

[Jeff Kleiner]

Why would anyone want smith gauges?

They make a perfect compliment to Lucas switches and relays ;)

Jeff

[Mike.Bray]

They make a perfect compliment to Lucas switches and relays ;)

Jeff

Be sure and pick up some of this while you're at it.

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