• Hi Guest!
    If you appreciate British Car Forum and our 25 years of supporting British car enthusiasts with technical and anicdotal information, collected from our thousands of great members, please support us with a low-cost subscription. You can become a supporting member for less than the dues of most car clubs.
    There are some perks with a member upgrade!
    **Upgrade Now**
    (PS: Subscribers don't see this gawd-aweful banner
Tips
Tips

Speedometer Question

Share this page

Ohiobugeye

Ohiobugeye

Senior Member
Country flag
Offline
Hi All, I have a 59 Bugeye with a 1275 / ribcase transmission with a standard 59 rearend 3.9.1, tires are 155/13" . I now have a Smiths 6144/00 1040 ( from a MG B I think ). The speed is way off, just driving up the street it is reading about 40 mph when in truth I estimate my speed at about 25 mph. Question is what speedo should I install to get a true MPH reading?
 
1376 Turns per mile. Your current speedo is 1040 Turns per mile. HTH.
 
If you have the stock BE diff and a 1275 you ought to swap to the 3.9 before worrying about the speedo. Ratio's are stamped on the flange that bolts to the axle housing at 10 O,clock as you view from the drive shaft flange. I'm running a stock speedo in my BE with the 3.9 and a 1275 and figure a 10% error that is easy to keep track of.

Kurt.
 
I have figured it takes about 2.5 seconds to go past 2 phone poles at 55mph. When in doubt "one thousand one, one thousand two" I have installed 3 speed odometers and this is what I have settled with. I will say my gauges are beautiful and light up well, but the tach and speedo are just window dressing. count and drive by ear, its all good.
 
No problems for me, I can run any wheel size, any tire size, any differential ratio, any transmission, and my Speedo will be dead on the money…
 
Speedhut GPS speedo?
 
Digital Speedo utilizing on of the Sigma Cyclometers is your answer. They read to 180 MPH. Easy to adapt to any Spridget. Glue a button magnet on botton of rear drum with JB Weld, Speedo head mounts on Rear View Mirror Bracket stud with a little creative engineering, right in best line of sight almost like a heads up display. A more heavy duty magnetic reed switch from a local electronics store, mounted w JB Weld to a piece of 1" x 6" steel strap can be attached to one of the rear spring mounting bolts and aligned with reed switch. One rotation of the wheel = speedo head updated with a pulse as reed switch is tripped by magnet. Can be calibrated in seconds to any size tire/wheel combination. Total cost with Wired not Wireless Speedo and misc parts and pieces depending on what kind of scrap stuff is in your garage $40-50 tops. A fun and interesting project. There is a thread, Google something like Lotus and Digital Speedo or something like that for details. Battery lasts 2-3 years in my experience with Bugsy.
 
Well, heck, just spring for a Garmin GPS and get the direction to address'es and map as well!

Kurt
 
Back
Top