Convert MPH to km/h

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AW-100

AW-100

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My -65 Barracuda has a speedometer reading in MPH, but over here our roads are regulated in km/h. Now Classic Industries have a new speedometer face plate to fit to my old speedometer reading in km/h, but they are all sold out. And they have no schedule for when they will start producing these again.

Is it as simple as adding 60% more teeth to the speedometer drive gear in the transmission to get the readings right, as km/h is 60% higher than MPH? (10MPH=16km/h)

speedopinionadapter.jpg

Here is an adapter from a 727. On my 904 I only have markings for 21-26teeth, and a drive gear with 26 teeth original. Can I turn my adapter accordingly, Even without profet markings, or can I fit an adapter from a 727 on it? My calculations says I need a gear with 40-42 teeth.

Thought about this one: [ame="http://www.ebay.com/itm/Mopar-Transmission-speedometer-gear-40-tooth-727-833-904-Dodge-Plymouth-/321555268227?pt=Motors_Car_Truck_Parts_Accessories&hash=item4ade300283&vxp=mtr"]Mopar Transmission Speedometer Gear 40 Tooth 727 833 904 Dodge Plymouth | eBay[/ame]


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Should be close but why bother ? I certainly wouldn't bastardize the speedo face , I just do the math in my head here in Canada and have gotten so used to it that I just know where the needle should be for all the key speeds , after all most place just have a couple of different speed limits and they are all multiples of 5 or 10 ,we only see KMPH speeds of 40, 50 ,60 ,80 ,90 ,100 and 110 around here so it's not that hard .
 
Um don't you need 60% less teeth adding teeth will cause your speedo to read lower not higher. and if you did find the correct gear to translate your speedo would only read up to about 70 mph is that enough ?
 
Multiply by 6 and drop the zero..now you have MP/H.

When I replaced my gauge cluster, I put an electronic speedo in..

If you have a cell phone that runs apps...n\make it into a speedo in KMS and use that...one of our members did that !

Good luck..

BTW, the states were supposed to go metric but never did..
 
this company sells speedo adapters to compensate for whatever difference you have or want. This ad shows a GM adapter but I think they sell them for any brand of car.

[ame="http://www.ebay.com/itm/360731753792?_trksid=p2060778.m1438.l2649&ssPageName=STRK%3AMEBIDX%3AIT"]Gear Ratio Adapter to Speed Your Speedometer Up 78 | eBay[/ame]

treblig
 
trapster said:
Um don't you need 60% less teeth adding teeth will cause your speedo to read lower not higher. and if you did find the correct gear to translate your speedo would only read up to about 70 mph is that enough ?
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Ahh, of course... I need a smaller gear, so the wire will turn faster to increase 60%... But I think I'll have a problem finding a gear with 10 teeth... :p My Speedo goes all the way to 120mph, so that would be enough if I got that to km/h. I'm never in a hurry driving the Barracuda... :)
 
Just put a little gauge vinyl 'cling' sticker on your speedo window, with a swing from 0-160 kmh. Match swing degrees from 0-100 mph. Make it with a computer program and reduce it to size on computer, then have a printer make it on clear vinyl. 100 here is 160 over there, and fractions thereof.


My thoughts on metric...go all the 'weigh' or don't go at all. Back to the old French Revolution metric time and all will work fine but metric and a 24 hour clock? Anarchy!
 
first find a set of 4.10 gears and then change the speedo gear.

or just put a plastic sticker on your dash.

:)
 
Considering that so many "do it yourselfers" have broken the speedometer needle when screwing with their gauge, I'll advise against it. As it stands today you do have some idea how fast you're going.
 
Mark up an inexpensive tach face with kmh ticks. Spot on with a manual, pretty close with an auto.
 
Download Ulyssess speedometer for your smart phone. It even has a trip odometer and a heads up display. I used that until I got new electric gauges. When I had a motorcycle that was imported from the UK, I used the 60% rule. It was close enough.
 
really multiplying the number on the sign by 6 and dropping the zero isn't that difficult geez ! I thought Norway had a decent education system , if it means that much I'm pretty sure Premium Dash Decals can either sell you or print you the decal you want , call them and ask .another place to call and ask is Charger Specialties , they do gauge resto and usually have a rack of decals at Moparfest .
 
Treblig said:
this company sells speedo adapters to compensate for whatever difference you have or want. This ad shows a GM adapter but I think they sell them for any brand of car.

Gear Ratio Adapter to Speed Your Speedometer Up 78 | eBay

treblig
Click to expand...

Looks like the Speedometer Adapter for a NP203 or NP205 Transfer Case in a 4WD Dodge. The 203 & 205 didn't have a removable/interchangeable Speedometer Gear like a regular 2WD 727, 904 or 833 does. It was just a 1:1 output I believe (I might be wrong on that number) And they used those boxes in place of a Speedometer Gear to match the gear ratio in the differentials.
 
bcschief said:
Did Canadian Valiants and Barracudas have KPH speedo's in 65 ?

Brian
Click to expand...

No, Canada didn't convert over to metric (with the exceptions of Oil Refineries and other businesses) until the late 70s..My '75 Duster's speedo, bought in Ontario, was MPH.
 
I agree with 1968DARTMAN - use your GPS - we all use them now instead of maps anyway - and for $100 at Canadian Tire, cheaper than the new speedometer and cable that I bought for my '66 Cuda
 
dodgedifferent2 said:
I went this route
http://premiumdashdecals.com/metric_speedometers.htm
Its a simple sticker you place on your speedometer and its all converted. I had no issues with it, but i have only had it for a year or so.
I had just planned on using my gps till i had all the speeds in my head. Or tape a small conversion chart on the dash
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Thanks, have contacted them and are awaiting reply as it looks like they might be out of stock. Is the decal very visible on the face, or does it blend in? Does it unstick in the corners or is the adhesive good enough? Can I bother you to take a picture of your Speedo?
 
i should be able to take a photo of it today. I know that i have had a few people already look at the dash and are shocked that i have a rare metric speedo in the dart (rally dash). I played along that i spent a few bucks on it, then later i explain what i did :)
 
AW-100 said:
My -65 Barracuda has a speedometer reading in MPH, but over here our roads are regulated in km/h.
Click to expand...

I bought a 65 Valiant KPH speedometer (which is the same as a 65 Barracuda) from someone in Finland or maybe Ulf (65dartcharger) in Sweden. It's going in a 65 Barracuda which is eventually going to the Netherlands to my oldest son - they use KPH there as well.
 
I can speak to the quality question. Premium Dash Decals are exactly that. Not cheap paper stickers. Not going to peel. Regards the quality, the install doesn't get any easier. There is some percentage of damaged needles. 1 of 100 ? Who knows ? Good luck
 
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