Speedo Recalibration Spitfire Mk2 1966

[KevinB]

Hi,

I'm looking for recommendations for anyone who can re-calibrate the speedo  in my Mk2 Spitfire please. It seems to work fine but is registering a much lower speed than I'm actually doing! 

Thanks

 

Kevin

   

[Qu1ckn1ck]

Speak to Speedy Cables      https://speedycables.com/

[Guest]

Also worth speaking with Tim at Speedograph Richfield: http://www.speedograph-richfield.com/ 

[Pete Lewis]

you need to know the turns per mile to recalibrate 

a simplish way to get this is 

mark 52.8ft carefully down the road or drive

remove speedo cable from head and fit card needle 

her you need some hands on

accurately push car the 52,8ft and count the turns of the needle  x this by 100

this gives you the turns per mile 

the number by the oddometer roll  shows what your speedo needs ,  aim for  up to10% fast  , cant be slower

if your  count is similar and your error is constant you may just need the needle re-positioning by hold the magnetic disc and carefully turn the needle to a revised reading 

never take the needle off its spindle or the hair spring will let go and youre in doo doo's

this involves speedo out rim off and two screws to release the mechanism,  easy DIY job

 

 

pete

 

[Guest]

Kevin,

Following on from Pete's reply:

If you send your speedo away to be recalibrated, by whoever that may be, the following form {see attached} will provide the calibrator with all the required information to do the job.

Regards.

Richard.

Speedo Calibration Form.odt

[DanMi]

Firstly does it need recalibrating to a different turns per mile or just reconditioning to original? The mark2 should have a 110mph speedo with 1248 turns per mile, this will be a number on the face to the top right of the needles spindle. If that is correct and the gearbox is a 3 rail and the diff still a 4.11 and standard diameter wheels then it will need resetting to original. maybe the magnets have weakend or needle moved.

It should do 50mph at 3000 rpm in 4th gear. If it reads this but you are going faster maybe the diff has been changed so you will need to change the turns per mile or get a speed from the car the diff came from assuming it was a 3 railed gearbox car

I used https://www.ebay.co.uk/str/classicspareseng1 when mine read high and is now pretty accurate. The 2 companies above will also do the job

[KevinB]

Thanks for all the replies, very helpful as ever 👍