Tach Tech - Mixing the old with the new

Who doesn't like vintage gauges.

I wanted a tach for Buckshot, but a new SW wings tach is about $120, then add for a tach cup. Plus, the new ones are all 8K, who needs that for a flathead

Ryans post about vintage tachs got me thinking, and looking on Ebay. I found a sweet 4500 RPM SW tach, and was the proud owner for $40.



From the listing of date codes at roadsters.com, it looks to be mid fifties unit, perfect.



The problem with vintage tachs, however, is the crazy sending units needed to make them work. I figured that I could convert an old tach to electronic, if I had the right donor, so another $15 on Ebay, yielded a new 6K SW tach.



I chose this model, because the sweep of the two gauges are very similiar and the new tach is adjustable.

I first started by ripping the guts out of the new tach by peeling back the bezel, then disassembling.







Next, pull the needle.



and remove the face.



I almost hated to do it, but now it's time to rip the old tach apart.



rip out the old drive motor.



and remove the rear housing



and the old bezel.



clip the drive shaft to remove the needle.



and remove the old faceplate.

 

I wanted to use the old tach cup, it looks cool and is a heavy gauge steel, but it is more shallow.



after making the old cup look like swiss cheese....



the new guts slid right in



I drilled the old faceplate for the two mounting screws, and glued the old needle to the base of the new needle, and pushed it onto the shaft.



Now, some head scratching....

I wanted the tach mounted to the column, but didn't have a mount, so after diggin around the garage, and a little welding, came up with this...



It's an old steering box clamp, half of a busted 3/4 inch wrench, and some flat stock bent to match the tach.

Here it is all painted and bolted back together. I used the back part of the old tach to cover the wiring studs, and routed all the wires thru a grommet.







Once it was wired up, I chained an old sun tach beside it, to calibrate. The needle can easily be remove and replaced to get it at zero to start, and by adjusting the pot on the back, the two tachs read almost identical.



Done! for half the price of a new tach, and it looks soooo cool.




Wanna see and hear it on my flattie?

Click here...


http://www.youtube.com/watch?v=ZtODALqk0FI

 

Great idea,thanks for the tech.

 

Excellent tech! Watching this to move to the tech archives....

 

great tachtech,congrats on job well done

 

i always wanted to do something like this, but didn't really want to tear into any of my old tachs. awesome tech

 

Cool tach.........Thanks for the tech..

Binga

 

I posted this pretty late last night, and I don't think many people saw it, so I'm gunna bump it.

Rich

 

Very nice tech!

Congrats on the spread in SR! ONly reason I noticed it was the H.A.M.B. decal in the windshield!


jerry

 

You Sly Dog You.
Looks Great.

 

Thanks man, I was pretty surprised to see it.

Rich

 

cool i may ahve to do that if i cant figure out my new/old westach

 

Looks great, how come the needle isn't zero'd out?

 

very neat thanks for posting

 

Awesome

 

I was wondering the same thing.

 

Yeah, a lot of the new electronic stuff doesn't "zero" until you supply power, which is what this one does.

My "new" wings gauges do the same thing.

Rich

 

Yes it does! I like it.

 

Clever! And looks great!

Jon

 

THANKS! should give so something to do when my little girl is sleeping! I hate sitting in front of the tv....

 

Kudoes to you dude! Nice tech feature!

 

Excellent. Even better: I found both guages in my box o' SWs! Now to get to work....

 

Great article to back up a cool idea, and the video made it all real....thanks man....

 

Really nice Tech article! I can't help but wonder if one could also have a decal made of an old gauge and then just reface the new gauge? Or would printed vinyl just not look right?

I do like the work you put into this, and the mount is top-shelf!

 

Can I put a Tach on a V8 Flathead that is still 6 volt? If so, can you tell me which tach would be best if I went new. I called around and everyone seems unsure, Summit had no idea. Just want a cool old looking tach to hang.

 

Good job, very clever.

 

Were you really drinkin MGD while working with vintage parts?
Are you still missing part of one finger?

 

Most tachs that were available during the 6 volt era were either cable driven or required a sending unit.

You just don't see any 6 volt electronic tachs, but I'm sure a specialty place like westach.com could hook ya up.

Rich