Series 2A/Stage1 speedo question

[65s2a]

What is the speedo cable drive ratio on a Stage1 V8? I have fitted 3.54:1 RR diffs in my S2A with 750 tyres (now love the gearing), and want to know if the speedo cable drive ratio on a stage1 V8 (that uses 3.54:1 diffs and has the same speedo format as S2A) is the same as S1, S2 & S3 (=2.25:1)
If it is the same, I'm thinking I could fit one of these speedos and it would read more correctly than the original SWB speedo that is expecting 4.7:1 diffs and 6.00 tyres? I would have to fit a S3 clip on speedo cable...
The original speedo does 1504 turns per mile, I need 1004 turns per KM or 600 turns per mile...which I hope is what the stage1 speedo does...any ideas? Thanks Les

[Lotz-A-Landies]

I don't think it is going to solve your problem as the Stage 1 V8 KPH speedo is marked 860 assuming this to be 860 turns per Km.

[isuzurover]

AS per Diana's post. Stage 1 ratios are completely different because it uses an RRC setup.

The easiest option would be to get your speedo recalibrated by Lionel Otto Instruments. I think there is even someone from there on this site???

[65s2a]

Thanks for the reply. I think I'm OK [or maybe I'm in space? ]...I have been experimenting with a spare S2A speedo and by changing the magnetism in the rotor in the speedo I can get the reading to change by probably 20%...by using de-gaussing coil from TV tube to de-magnetize or if I over do it, using a powerful magnet to re-magnetize the rotor, I can lower the 860turns per KM to 600 turns per [mile] as the KM speedo would now read..? I'm encouraged !! (hope this activity isn't seen as wierd amongst LR owners) Cheers Les

[Lotz-A-Landies]

Will that change the Odo or just the speedo?

Diana

[65s2a]

Good thought...ODO would still be wrong... I'm thinking how important would that be?

[Lotz-A-Landies]

Most automotive instrument people can add a little gearbox in the cable to convert between the speedo and the error.

I've not done the calculation, but you may find that the KPH speedo for a SIIa/SIIb forward control is almost the correction you need. (If you can find one.)

[65s2a]

Yeah, I've seen those...quite costly [in my S2A hobby world] but the main turn off with the ratio adaptors is I didn't get to improvise what may be reasonably available to me to solve my problem using research, collective knowledge and potentially innovative maby old school [or even silly] ideas...which for me is what makes the Series LR rebuild journey what it is...
I paid a farmer in out back NSW $100 twelve years ago for "Hillston" and it was absolutely stuffed, had an unfeasibly large water tank on top of it...sitting under a tree cos the clutch had blown up no doubt due to the weight that it had to carry, all the chassis stop rubbers had been worn to nothing and the chassis had cracked and warped...any sane person would have used some of the parts but for a more suitable restoration candidate...nope, I decided I needed to do this one up...wasn't looking for easy...lots of stories but back to the point, The ODO issue Diana rightly brought up is the only thing that may turn me away from tweaking a speedo to read correctly...sorry for the rant. Thanks Les

[TJWA]

Hi 65s2a. Did you end up carrying out a solution? I'm in the same boat here in a Series III. 3.54 Diffs and 7.50 tyres.

I'm thinking about calculating how many turns per kilometre are required then finding a speedo to suit from another vehicle that will accept the cable.

Are you sure you require 1004 turns per KM? My S3 SWB speedo is marked as 880, I would have thought that changing to 3.54 diffs and 7.5 tyres would LOWER the turns of your speedo per kilometre.

The speedo cable is spun at the final drive of the transfer case to the rear diff. If you have 3.54 diffs then it's going to take less turns of the shaft to travel a kilometre?

As the Stage 1 had 3.54 diffs I would have though it's speedo would be correct? Although my mental calculations would put it at 800 turns per kilometre not 860 as Lotz-A-Landies has quoted is written on the front of a Stage 1.

[HBWC]

this may help i know its for triumps and mg but the iner workings are the same
http://home.comcast.net/~rhodes/speedo.pdf