The Stovebolt Site Forums The Shop Area General Truck Talk KPH Speedometer

thought folks might be mildly interested to see this item i just got from ebay

it appears to be an original metric speedometer that replaces to 0-90 MPH version
i bought it for just the dial face, so that i can know how fast i'm going in Saskatchewan

if someone can make this face into a printed sticker that would be neat
else i might make a printable PDF version and explore the options to printing my own

When you make up the new dial, you might be able to put the MPH scale on an inner ring. That way you can use it on either side of the border.

LOL
An old guy I used to work for bought a then-new Chevy in ~1980 and drove it up thru Canada. When he got here, he complained about not knowing how fast he was going. I had to point out to him that there were KPH numbers inside the MPH markings (I had the same model Chevy.)

Nice item. Unfortunately none of the vendors make a gauge repair sticker kit for you Canadians. I think a guy could make a sticker from a photo. And with a little bit more editing on the photo, you could add the MPH numbers like Gord suggested. Matching the color might be a little tricky, but doable, as would be "removing" the rust on the numbers.

Just have to remember Km are 5/8(.625) of a mile.

Ed

A 1980 Chevy is metric yes, but an AD. I find that really, really,....really hard to believe. ALL of my ‘77 and earlier GM Canadian products were mph. ALL of them.

I wouldn’t resurface it just in case it’s an original. Were there any other countries using metric back then that manufactured GMs? Maybe it’s a fake? This is a tricky one in my mind. Very strange.

At the very least, at least it will keep you sharp on multiplying fractions!! 😎 I thought you’d like that one, HRL!

Perhaps Brazil? They were making GM trucks in the 50s and were using the metric system before then. (AFAIK)

It come from Venezuela
They had metric back then already
So GM made the KPH speedos for that market

Very cool!

The interesting part would be calibrating the odometer to read in KM instead or miles!
Jerry

If it was built as a KPH speedometer, that should have already been taken care of. If a guy was trying to convert a MPH speedo to KPH, the odometer would definitely be off (still reading in miles).

Change gears in speedo reducer.

Ed

My bet is that those speedometers read kilometers per hour on the needle, but miles on the odometer, which means that nothing under that KPH dial is different than the speedometers which we have with MPH and miles like Jesus did in the Bible.
Carl

the dial face cleaned up reasonably well, i'm gonna use it as is, it will match the other aged instruments in my truck
the photos attached are "cleaned.jpg" this is the result of 48 hr room temperature soak in Evaporust cleaner, then gently rinse with cold water and massage any particles off with fingers only not even a brush.
then it air dried well for a couple days
"coated.jpg" is after i applied a thin coat of Rustoleum satin clear to help stabilize the surface to lock everything in place and prevent new rust
the back side will get a new coat of plain white

i'm gonna definitely check out the odometer later to compare to the 0-90 MPH cluster, i suspect it will be in miles
but i'm curious now to see if i could find appropriate gears to turn it into a KPH odometer. gonna put a pin in that idea

Hy 2ManyTrucks, back when Canada metrified there were speedometer adapters being sold to make our speedometers read in Kilometers per hour rather than miles per hour. I bought a couple of them, but I only installed one, I have another brand new one around here somewhere.

Old British motorcycles, of which I own several, used Smiths spedo drives that came in Mile and metric flavors. Miles units resulted in 1000 revs per mile and metric were 1600 revs/mile. The standard for miles on US spedos is 1000 revs/mile. Speedo shops have or can get adapters that are used on trucks when axle ratios are changed. They come in many ratios. So there may be one for a metric conversion.

Tommy has the answer. Spin the speedo thru 1000 turns by hand. If it added 1 unit, the odometer is in miles. If added 5/8 of a unit, the odometer is in km.

Well it could be that the speedo itself is the same on both sides of the border, the printing on the face of the speedometer is placed differently.
Just a thought
Steve

Very interesting, thanks for sharing. I am guessing the odometer is in kilometres.

i measured the odometer
it appears to be in Km!

i turned it about 60-65 times to get the tenth to move one whole unit
so that means it would be about 600-650 turns to get 1 unit increment on the odometer

if the truck cable from the transmission is indeed 1000 turns per mile, then it is also 621 turns per Km
since this odo counts up 1 with 600-650 turns that means it will count 1 Km on the odo with a cable turn rate of 1000 turns per mile.

neat

Here is a YouTube video of a cool 1951 with Uruguay license plates. About 40 seconds in you can see the KPH speedometer. The truck has some other interesting features.



Your gauge face turned out great. Good work.

Interesting. Looks like it has a custom fabbed tubbed bed (or something from a later truck maybe a different brand?) Done quite a while back gauging from the similar finish on cab and bed.
Also a cute little bowtie emblem between the speedo and instrument cluster.

that's a nice video Frank50,
thanks for the link!

i see that in the video that truck as a metric speedometer version of the 0-80 MPH
whereas my metric speedometer is the counterpart to the 0-90 MPH
so now we have evidence of all 4 speedometer variants

for interest sake, i counted the gear and worm teeth to calculate the exact turns to unit count in this metric speedo.
input shaft worm to first gear ratio 11:1
first gear-worm shaft to second gear-worm shaft ratio 8:1
second gear-worm shaft through idler to 1/10ths Odo wheel is 7:1

multiplying those ratios get us to 616 input shaft turns to 1 complete revolution of the 1/10th unit which counts up 1 KM

If you want to make a waterslide decal, just let me know. Some of you may remember I did this about a year ago to convert a 0 to 80 mph electronic speedometer to look as close to possible as the original one. You can still see that work in the electronic bay section somewhere...

There it is: https://www.stovebolt.com/ubbthreads/ubbthreads.php/topics/1343677/1.html

When you get to around page 3 you should see the work I was doing on the SpeedHut speedo conversion (which is about as close to original as you can get with the lcd display for odometer, etc).