6 V Tachometer

[51er]

I read somebody asked about a 6 volts tachometer for our cars, Westach made it in nice different styles, along with many other gauges. https://www.westach.com/product-page/2ct34-6v-nc
Tried to upload a pic but couldn’t be able by my iPhone

[RalphG]

Thanks, they are more expensive than I'd expected. Only 3500 rpm but that would be plenty for most flatheads unless they are into racing.

[Merc Cruzer]

The nice thing is, the Tach doesn't care if it is 12 volts or 6 volts. If it has a light in it, then change the bulb to a 6 volt bulb. I used an old Trisco tach and it worded great.

Pos ground, just switch the lead and ground wire

Go on e-bay and get one for an 8 cylinder in your price range and size:

https://www.ebay.com/itm/28397168182...Cclp%3A2047675

The older ones had a lower range, more appropriate for the Flathead.

It was just an experiment and I took it out, after I made a video with it, to test the shift points on my transmission. I could just as easily used my Snap-on dwell/tach gauge.

[tubman]

Boy, I don't know about the above. I have spent a LOT of time with my 6 volt positive ground "Tach Driver", and it's not as simple as most think. We tried running 12 volt tachs on 6 volts (switching the polarity) and never go one to work. You have to boost the voltage AND change the polarity for both the logic and signal circuits. Plus the "dirty" power from an old car with a generator will raise hell with the circuits in modern tachs. We finally did come up with a device that would reliably run any new tachometer on a 6 volt negative ground vehicle, but by the time we had developed it fully, it was too expensive for most people.

If you doubt my veracity, check this out : https://www.youtube.com/watch?v=TaxpuDkWAqc. t shows the device we developed hooked up to a '51 Mercury engine (running 6 volts positive ground) and a "Sun-Pro" generic 12 volt tach. The engine starts, we rev it a couple of times, and then pan down to the engine and finally the 6 volt Optima. I still run these on a couple my of my own cars with no problems.

Funny, one of these plus a cheap 12 volt generic tach was priced about the same as a "WestTach", but just wouldn't sell in volume. BTW, in my opinion, "WestTach"'s 3500 RPM range is not nearly enough, even for a stock flathead, and in my opinion, one would look more at home mounted on a tractor.

[Merc Cruzer]

tubman,

I am wondering if you use a "modern Tack" vs a very early Tach, creates issues the early tach's didn't?

I am thinking that instruments used early on, were more forgiving than the latter ones, similar to my Snap-on tach-dwell meter. It seems to address use on all vehicles of that era.

A couple of pictures of the owners manual, for the Snap-on MT416 Primary Tach-Dwell Meter

[51er]

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Well, I tried to put a 12V Sun Pro tach in my 6V neg ground 51 coupe and it works in a erratic way. Those old style 6 volts tachs just like the ones on eBay needs a transmitter box to work OK. And a good and reliable kit (tach+transmitter) is way to expensive.

[tubman]

Originally Posted by Merc Cruzer

tubman,

I am wondering if you use a "modern Tack" vs a very early Tach, creates issues the early tach's didn't?

I am thinking that instruments used early on, were more forgiving than the latter ones, similar to my Snap-on tach-dwell meter. It seems to address use on all vehicles of that era.

A couple of pictures of the owners manual, for the Snap-on MT416 Primary Tach-Dwell Meter

I really hate to "be one", but you are way off base here. The early tachometers were "meter tachs", meaning they were basically ammeters that needed to be driven by a special controller box that had a bunch of archaic circuitry and goofy (1.7 volt?) batteries. Most of these batteries corroded over time and ruined the controller boxes. This is why you see so many older tach "heads" up for sale on places like eBay. They are completely useless without the controller box. I have a pretty good reputation about these old set-ups and am constantly being approached by many folks who would like me to "fix" their controller box. We can do it (and have done it several times), but most people don't want to pay what it costs.

Modern tachometers are what are called "motor" tachometers, and operate on a completely different principle that the earlier units.

Technology marches on.

[Merc Cruzer]

tubman,

Thanks for the clarification. So rather than an old Sun Tach, (I have deleted the reference to Sun Tack's in my prior post, based on your explanation) that requires a "special controller box", the reason mine works, is that it uses newer technology, thereby allowing it to work on both 6 volt and 12 volt, Pos and Neg ground systems?

I stand corrected, and thank you for the education.

As it turns out, mine is a older model, of the Trisco S-670 tach. The only place I can find to buy one, is at your Local Butler Auto Mart:

http://butlerautomart.co.nz/our-rang...tion-S670.aspx

Location:261 Stanmore Road
Richmond
Christchurch, 8013
New Zealand
Contact:Phone: 03 3898830
Fax: 03 3893895
Email: Stanmore Branch

Location:407 Colombo Street
Sydenham
Christchurch, 8023
New Zealand
Contact:Phone: 03 3668005
Fax: 03 3655895
Email: Sydenham Branch

I also have another one I will be trying tomorrow.

[tubman]

Thanks, I'd like to get my hands on one of those, but up here in northern Minnesota, it's probably quite unlikely.

I'm glad it worked out for you.

[Merc Cruzer]

My brother-in-law gave me both. If I remember right, he said the blue one came out of an old Jeep.

It reads: Patent 3005155 Thomas G. Faria Corp. Uncasville, Conn.U.S.A. A12430-60-8

[TJ]

Westach must have sold the business to someone in the So. Cal. area. They were in Sonoma , Ca. and went out of business up here. Glad to see they are still around.

[5851a]

I have a Ford dealer over the counter Faria tach. 2 wires, coil feed power wire in and out to coil. I'm using it on 12 volt but it's after the resistor wire. Seems to work fine, kind of like the old dwell/tach meters did. Never tried on 6 volt or positive ground though. Kind of figured it worked like an AC voltmeter. Ford in dash tachs were wired in the same way, or the ones I owned were in the 60's to mid 70's.

[Merc Cruzer]

Originally Posted by 5851a

I have a Ford dealer over the counter Faria tach. 2 wires, coil feed power wire in and out to coil. I'm using it on 12 volt but it's after the resistor wire. Seems to work fine, kind of like the old dwell/tach meters did. Never tried on 6 volt or positive ground though. Kind of figured it worked like an AC voltmeter. Ford in dash tachs were wired in the same way, or the ones I owned were in the 60's to mid 70's.

Hooked up the tach in series (Unhook the wire from the coil to the distributor. Then I hooked up the red wire to the distributor side of the coil. Then I hooked up red/white wire, to the wire from the distributor to the coil and it works perfectly. Picture worth a 1000 words, so see picture below.

Now I have two different tach's, that hook up completely differently, and yet they both work, on a completely original Pos ground 6 volt system.

51er:

Bottom line there are allot of options out there for you, just avoid Sun Tach's with driver boxes!

[51er]

[QUOTE=Merc Cruzer;2143798]Hooked up the tach in series (Unhook the wire from the coil to the distributor. Then I hooked up the red wire to the distributor side of the coil. Then I hooked up red/white wire, to the wire from the distributor to the coil and it works perfectly. Picture worth a 1000 words, so see picture below.

Now I have two different tach's, that hook up completely differently, and yet they both work, on a completely original Pos ground 6 volt system.

51er:

Bottom line there are allot of options out there for you, just avoid Sun Tach's with driver boxes![/QUOTE

Yeah, I already ordered one from Westach, I really liked the old school design with 6V modern guts!