rigging up old tachometer
 

I was going through all of my grandfather's old stuff in the garage at my grandma's and I managed to find a still intact Smiths Tachometer. Sure it only goes up to 60 x100 RPM, but its fuckin' old school pimp.

I think it might've come off of one of his MG's or Sprites, I dunno.

How would I go about installing this tachometer? I measured and it has a 12mm threaded input on the back. Could I use another tach's cable?

Anyone know anything about Smith Tachs? Google says they're electric.. huh

12mm threaded? That's gotta be mechanical then. Similar to the speedometer cable.

There're adapters where you can get the speed off of the Metering Oil Pump driveline, but that means you have to premix.

make a clock out of it

I do already premix. I was planning on blocking off my OMP, but.. what is this you speak of?

just to check here, it's not coax is it? it could have an electric pulse input.

It's almost certainly mechanical...will require a cable being driven off a gear on the camshaft...oh wait a minute, we don't have a camshaft. Post pictures.

Rich

hmmm, actually, thinking about it

it might be coaxial

I'll post up some pics when I get home from class

Nope, its definately mechanical.

1. How do I go about using the OMP to hook it up to see if its accurate for use?

or

2. Should I try putting the innards of a cheap electric tach in it?

pics will be scanned shortly (yeah, I'm just placing it on a scanner)

The best way to go about this is to just discard the tach. To get a mechanical tach to work right would take a lot of work, and hardly be worth the time and money. As for putting the workings of a cheap electrical tach into it, you might as well just use the cheap tach you buy. The scale the new tach would use is likely different than the ones on the tach you have, meaning it wouldn't read right.

haha dude, why bother? always trying to be innovative :) just get a tach thatll actually work

You'll see!

You'll ALL SEE!

I found a website that actually takes INTERNET SERIOUSLY!

No really, I'm taking up the mechanical to electric conversion: http://www.britishcarforum.com/lore/...ment.php?id=12

And I've already found a donor tach with the same 270* sweep and 6k RPM range. AWESOME!

Here is a pic of the tach I managed to hunt down with the part number.
http://www.britishmiles.com/parts/images/rn2313-00.jpg
Apparently its from a Bugeye Sprite I. So its almost 50 years old. Yes I have no problems converting a $200 historical tachometer for use in my RX-7.

And its getting the guts from this tach: An ISSPRO I managed to get new on ebay for $30 as opposed to $120 from http://egauges.com/vdo_ind.asp?Type=...EVA-R&PN=R5591
http://egauges.com/images/isspro/Large_d/R5591.jpg
Yes I have no problems ripping apart a brand new tachometer.

And its going on the passenger side of the dashboard, near the a-pillar. I think the passengers should have a tach to watch, too! It'll be fun freaking them out.

That thing looks really nice, will you mount it in the usual dash location or someplace more showy, like above the clock?

read the line right above your post, Zephy

I'm sorry wasn't paying attention to anything under the picture, doesnt sound like a bad idea, I have yet to see that done on another car.

If I don't screw up the conversion, its going to be pretty badass.