I agree with leaving it alone. Besides creating your own scale as Dartnut suggests, You could also use a speedometer app from your phone. That's what I'm doing until I can fix my speedo problem. (No, I don't have a bathing suit problem.
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Switching from Km, to MPH.
- Thread starter moparmark65
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)I guess I'm lost, why would the gear need changing whatsoever? Unless the actual range of indicated speed is different, i.e. 0-120mph vs 0-150mph, it should remain the same, only need the desired speedo/odo installed. The calibration is simply in the markings on the face, not pinion speed.
Dave999
Well-Known Member
does nobody make new speedo dial decals
just swap to a MPH scale
i.e leave the pointer and gears alone and alter the scale.
at one point in the UK you could get MPH decals and KPH decals to allow compliance with standards when using a car you imported or taking a car to a KPH country
Australian valiants also went through a MPH to KPH change and you could get new speedo face decals to assist with the swap...
nobody messed with gears or gauge calibration. Just stuck the decal on and pretended that km were miles for the odometer
just swap to a MPH scale
i.e leave the pointer and gears alone and alter the scale.
at one point in the UK you could get MPH decals and KPH decals to allow compliance with standards when using a car you imported or taking a car to a KPH country
Australian valiants also went through a MPH to KPH change and you could get new speedo face decals to assist with the swap...
nobody messed with gears or gauge calibration. Just stuck the decal on and pretended that km were miles for the odometer
moparmark65
Well-Known Member
I actually just ordered a set, classic industries sells them. I will try that first. Then worry about calibration after that! And I think your onto something, my speedo is like 240km, decal set goes to 150mph
Dave999
Well-Known Member
well the speedo section is working the same all you did was move the numbers
but i presume the gearing for the tiny gearbox that rotates the miles or KM counter must be set for one or the other...
i.e going 1 Kilometer turns the 3 or 4 gears in the odometer enough to click through 10 tenths and then next tumbler clicks onto 1 Km 000001.0
and the odometer reads 1 i.e the distance you travelled is 1
if i travel 1 mile
its going to read 1.6...
1 mile = 1.609 KM
000001.6
so if i change the decal to miles for the speedo, if they printed it right, it has a different scale and everything should be fine for indicating your speed but, the mile counter (is still really a km counter) will read 1.6 for every 1 mile you do, as it did when the speed decal was in KM.
which would eventually grossly overstate the mileage.. the car is however so old, nobody really cares, unless of course you are on a mileage limited, historic car or club car insurance scheme. (UK and Aus have these you may not in the US/Can/Mex)
in which case you will be paying over the odds because you would seem to be doing 1600 miles for every 1000 you drive.
Dave
but i presume the gearing for the tiny gearbox that rotates the miles or KM counter must be set for one or the other...
i.e going 1 Kilometer turns the 3 or 4 gears in the odometer enough to click through 10 tenths and then next tumbler clicks onto 1 Km 000001.0
and the odometer reads 1 i.e the distance you travelled is 1
if i travel 1 mile
its going to read 1.6...
1 mile = 1.609 KM
000001.6
so if i change the decal to miles for the speedo, if they printed it right, it has a different scale and everything should be fine for indicating your speed but, the mile counter (is still really a km counter) will read 1.6 for every 1 mile you do, as it did when the speed decal was in KM.
which would eventually grossly overstate the mileage.. the car is however so old, nobody really cares, unless of course you are on a mileage limited, historic car or club car insurance scheme. (UK and Aus have these you may not in the US/Can/Mex)
in which case you will be paying over the odds because you would seem to be doing 1600 miles for every 1000 you drive.
Dave
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Yep the speedo is doing 60 mph or 96 KPH at 1000 shaft RPM ( iirc) so the needle is in the same position either way. but my understanding is the op wants to use the same scale (0-200 or whatever it is for his KPH speedo) but have the needle point to 60 at 60 MPH so the shaft speed would need to be about 60% slower at 620 shaft rpm.
Dave999
Well-Known Member
which moves him into converter territory
transmission speedo output into electronic box 1000 rpm cable rpm needs to be the input and electronically measured and converted to a signal into a stepper style motor used to turn the output cable into the speedo at 620.
you could make one but buying one is probably in the 400 bucks or more area
would be easier to put a tone ring on the prop shaft/pinon/ disk rotor mount a pickup and use an electronic pulse from it into the electronic to mechanical drive box......
still gonna cost more than a decal...
this way you could appear to have a 240 MPH speedo
however the resolution in the area that is in the legally binding speed limit range is probably not going to be good enough to accurately sit on the limit and not get pinged by the cops
as you are using only one 1/4 of the scale to measure the legal speeds. normally you would use 1/2 to 3/4 of it
crappy old speedo wasn't that accurate to start with so making it worse is not a good idea
Dave
transmission speedo output into electronic box 1000 rpm cable rpm needs to be the input and electronically measured and converted to a signal into a stepper style motor used to turn the output cable into the speedo at 620.
you could make one but buying one is probably in the 400 bucks or more area
would be easier to put a tone ring on the prop shaft/pinon/ disk rotor mount a pickup and use an electronic pulse from it into the electronic to mechanical drive box......
still gonna cost more than a decal...
this way you could appear to have a 240 MPH speedo
however the resolution in the area that is in the legally binding speed limit range is probably not going to be good enough to accurately sit on the limit and not get pinged by the cops
as you are using only one 1/4 of the scale to measure the legal speeds. normally you would use 1/2 to 3/4 of it
crappy old speedo wasn't that accurate to start with so making it worse is not a good idea
Dave
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moparmark65
Well-Known Member
I will certainly check the gear in transmission, my book says the orange gear is what i need for the gear ratio and tire size. I will get speedo face done then use GPS to try and dial it in!
autoxcuda
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Just buy a used 120 mph speedo from a 67-69 Barracuda.
But find out if your speedo has a screw on receptacle for the speedo cable OR a clip on. And get the appropriate rallye speedo gauge.
I'm sure someone with gladly trade you just to have a KPH speedo on the shelf too.
But find out if your speedo has a screw on receptacle for the speedo cable OR a clip on. And get the appropriate rallye speedo gauge.
I'm sure someone with gladly trade you just to have a KPH speedo on the shelf too.
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OttawaCharger
Well-Known Member
Mr heater box will convert them over to kmph if you want.
I have thought about that, the modern cars use that type of thing
Dave999
Well-Known Member
all kinds of kit to do it and details on how to use arduino etc with hardware from digi-key.. all too complicated or expensive for me....
easiest is tone ring and pickup with wire into box under dash with a short cable drive into back of speedo But mine works mechanically so i never got any further. was gonna do one for an electronic speedo t5 , pluses in via conversion to pulses out into the motor drive turns speedo at correct rate.
marksmopar1
Well-Known Member
Simply install the repo sticker over your current speedo face, done. 60 kms is 36 mph for example, the needle will be in the same place on the speedo it’s just the location of the speedo numbers that are placed in a different location to read correctly. The sticker will put the numbers in the correct location. But, your trip odometer and mileage counter that will remain in kms or miles depending on its original calibration.
Sometimes it's just a waste of oxygen trying to convince those who know everything.
A very good friend of mine found this for me to swap out the mph to kmph odometer. They are out there....and this is a 1968.
moparmark65
Well-Known Member
Thanks for that. I actually found a guy up north of the border, ( mr. Heater box) that will rebuild a MPG speedo and swap it for the KPH one. They are quite rare and he can make some money on it.
moparmark65
Well-Known Member
Thanks for the hook up! I talked to him, he is going to rebuild me a mpg, and swap it for the kpg. The kpg’s are rare and he can make some money on it, and I get a nice mpg speedo. Win/ Win!!
I think it’s easy for us after 50 years of doing the quick math, that being said, I would think having a factory kmh speedo in my 69 GTS would be kind of cool
moparmark65
Well-Known Member
Thats the easy part, but to convince a potential buyer down the road that the odometer is kph and not Mph is what I want to avoid!
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