Technical Cool Vintage Stewart Warner Vacuum Tachometer Motometer Gauge Pictures history and help

So I found a few of the large Stewart Warner Vac-Tach gauges and want to run them on the 1932 3w. I don't see them being used and wonder why and who has them ? I was told I need a box or sending unit and can this be made or where can one be found?
Plus how old are they and what was the original application thanks!

 

Not originally used on hot rods. What self respecting rodder would pay good money for a tach that only goes to 5000?

Probable original application was some industrial equipment or truck. Maybe a very large truck with air brakes that required the vacuum reading?

Yes, you will need a special SW sender that is sandwiched under the distributor cap. Very hard to find, and each type/brand of distributor requires it's own shape of sender. The sender is basically a little generator/motor that is spun by the distributor shaft.

Does the number stamped on the back say W5? That would be May of 1953.

 

Ha ha ha yeah the 5k tack will limit its use but running a Flathead should be awesome . Do you by chance have a picture of the box and thanks for the date..

 

I don't have any pics of the sender, but it looks kinda like a butterscotch colored distributor cap, without the plug wire ports on top. It has a cable coming out the side with a plug like your tach has. And in the middle is a chunk of shaft that the rotor will plug onto. Some have clip bosses on the sides if that particular distributor uses clips.

 

Mine came in a 1948 White WB something US Army bus, has the adaptor under the dist. cap as alchemy's. It was clamped to the mast jacket with a factory looking mount that would hold an anvil ...

 

I just picked up one for myself to run with my Mculloch supercharger on my flathead. keen to hear others input

 

I found a old ad on that auction site and it had a picture of the box. I thought the tach was hard to find not the hunt for the sender is on and will put a want ad in the classifieds .
Has anyone run one of them?

 

Another pic of the sending unit

 

I've been looking for one of these too and was the second bidder on the one pictured above. I think the only way you will get one of these to work reliably is to gut it and convert it to modern electronics. The sender above was a 762 S 4X, which I think was for a Mallory 4-6-8 cyl, probably a 4 cyl, and it may or may not have been working. I hate to think of that thing rattling around my distributor anyway. Another thing I was worried about was the length of it, it looks like its 5 or 6 inches deep and that may not clear a working cowl vent on a '32. I'd be willing to take a chance and convert one if I don't have to pay too much for it. I think they also make a mechanical version of these too but that presents a different set of problems (I hate cables). Everything I know so far has come from fleetside66, who really knows his vintage Stewart Warner gauges and has helped educate me. I bought this 5" multi-gauge set from him so I want a vac-tach to complete the set for my Deuce roadster project.

He still has this set for sale, a very nice 5" multi-gauge set.
https://www.jalopyjournal.com/forum...w-5-all-in-one-gauge-matching-speedo.1102635/

 

I have to say I wasn't sure how it hooked up but liked the look and will figure it out. I am not a fan of how it does hook up and being mine will be in a 32 space also will be a issue.
I wish some one had a details of what's in the sending unit and or a schematic would be awesome.

 

I had book marked the auction on the tack and sending unit but missed it due to not having my phone on me and would have paid more just to take apart the sending unit..
I like that gauge set you have do you know what it's from? And year?

 

This was in my Deuce Ro. when I got it. The vacuum gauge works and the tach is hooked up as a speedo. Indicated 1500 rpm is 50 mph in fourth. Once on the highway, I'll figure out the speeds at higher rpm's.

 

So I plan to run the vac tach next to my police special speedometer and it's a 5 inch gauge

 

That's wicked cool and wonder how they did it? I'm going to pull off the back on mine and see what the skinny is on the guts of it....

 

Looks like they had a speedo cable made and attached it to the stock location.

 

If you're interested in having one converted get a hold of Williamson's Instruments, they did a fantastic job converting my Sun Tach.

 

Thank you Alfin32 for the rear view, I just took my back cover and this is what's inside . The round disk in the center is hooked up to the tach needle. It also looks like it's making a pulse and sending current into the 4 windings on the outside and 6 pick-ups generating electricity to spin the tach needle on the spinning disc or this would be the armature.
So we have to say the missing sensor is creating a low voltage pluse to spin the needle at various speeds. It is using the rotation of the distributor and I am sure spinning a electromagnetic motor for the voltage ..

 

Nice Deuce dashes guys! The tach with all those windings it must weigh quite a bit! If you remove all of that and put a modern tach mechanism in it that would shorten it up a bit too. I think it would be workable, especially to one of the specialists that work on gauges. It looks like Williamson's Instruments would be a great choice to convert it. Notice how much shorter the mechanical version is than the electrical version. I'll have to ask Greg (fleetside66) if he knows where my gauges came from, I'm thinking a they are from a truck. Here's a pic from his 1957 Stewart warner catalog showing them and what you needed when they were new.

 

Thank you for the info and the good experience from them and very refreshing to hear . I have been intrigued by the vintage tachometers and it's sending units for many years. I have collected dozens of the football sun tachs and the black face ones as well and Stewart Warner as well, old gauges are cool!!!! I do have a number of transmitter boxes for the sun tachs but none for the SW. I have converted the old sun ones using hearing aid batteries to achieve correct voltage . They work good but finding a good correct box that reasonable is getting harder. The Stewart Warner ones are crazy hard to find and too many hoarders in my area.

 

Continentaljohn, Studebaker used a sender that sandwiches between the distributor cap and body for their Stewart Warner tachs just like the one in the pic if that helps you find one.

 

StudebakerJoe Interesting and cool thank you and will have to see if I can find one

 

Hope this helps. It's not an actual pic but will give you an idea of the insides of the sender.

 

Joe thanks for the diagram and makes more sense . I am still looking for one to take apart and possibly make a couple

 

I wonder if this setup could be removed and simply converted to a mechanical tach, similar to alfin32's setup? I wonder if Alfin32's is really a different unit entirely, or if it came from the factory without the motor on the back to drive it and some sort of different adapter to drive a cable?

 

For what it's worth, here's my buddies with the rear cover and motor removed. Note that it does look different than alfin32's mechanical version. Still, if this could be converted to cable it could be a great alternative to an expensive conversion or impossible sender.

 

Here is a pic of my mechanical one, plus the original cable. Everything seems to be pretty straight forward & looks like the rear of every other S/W tach & speedo of the era. This one is 1948. BTW, it's interesting to note that the little vacuum gauge is plain white, as compared to the colorful ones. Alfin's mechanical one pictured above is white, too. Maybe the mechanical ones are white & the electric ones colored? Or, maybe the later ones were colored & the earlier ones white? The mystery goes on. S/W did some very strange things & these gauges are no different. I'm looking forward to getting the scoop on the first converted one. Something tells me it might have something to do with hoops of fire.

 

This is one I have for my flathead. The distributor unit is a generator to spin the tach. I also have one in my roadster with the 49 olds engine. Gary

 

I came across 1944 army technical manual on google that shows how to take apart and repair some types of SW and other brands of gages. Here's the link, may not be exactly on point but I thought really cool and shows tools for removing and replacing different types of bezels. https://books.google.com/books?id=H...w to take apart a stewart warner tach&f=false

 

Well it works but it reads too fast, but about 4:1. I talked to a speedometer shop it sounds like it's an easy fix for them. They said they would just change the magnetism, just like calibrating a speedometer. At this point we've found an original mechanical so this hit the back burner. If someone's interested in taking it from here let me know it may be available.

 

I wonder if the pulse type Alt ., that a Diesel truck used would Power one of these . Pulses are generated from the stator windings . I know Alt ., probably is not an option , just something to keep me wondering if it would work or not . I have a pulse tach on my BT Cummins , it works great and was super easy to locate and wire into operation .