Speedo Confusion

[Jaars]

I have several speedometers, but do not know what they go with. I need one for the Venezia which will has a S5 synchro transmission and the old 4.22 rear-end. From previous posts I realize I might want to change ot a 3.88 rear.
Obviously I like to use a new one. The turns/mile numbers vary so much!
Here is what I got:
SN 5338/00 1536 1 mile New with clear label indicating how to reset
SN 5338/01 960 2 miles New with clear label indicating how to reset
SN 5338/12A 1504 70558 miles
SN 5338/25A 1000 17 miles looks new

Anybody can shine light on these numbers?
Thanks, Robert

 

[Bill Blue]

A couple of years ago someone said the 1536, 960, 1504 and 1000 are speedo cable revolutions per mile.

Bill

 

[Series3Scott]

Robert - found a listing for SN5338 in the Hillman Super Minx parts book.

 

[Wombat]

Robert

Can't help with the part numbers (none are listed in my SI to IV parts book) but I have done the sums.

With 165R13 tyres the circumference is 6 feet (give or take a little bit). This gives 880 turns of the wheels per mile. Depending whether your speedo pinion has 14 or 15 teeth the cable turns per mile with a 4.22 should be:

15 teeth 990 rev per mile
14 teeth 1060 rev per mile

I don't have the tooth count for the Alpine, but the Arrow range used 13, 14 and 15 teeth for the 3.7, 3.89 and 4.22 respectively. I might go out on a limb here and suggest the Series V has a 15 tooth pinion. There was a change in part number in the late SIV when all cars for the North American market were fitted with the 4.22.

Hope I haven't totally confused the issue.

 

[lemansvk]

Given that the Venezia is much closer in derivation to the Humber Sceptre than the Alpine, the 5338/Super Minx connection that Scott made makes sense. I guess what might help is a Sceptre parts or workshop manual. There is one online somewher but I'd have to search for it.

Incidentally, from looking at my Alpine WSM I'd suggest that numbers around 1000 indicate revolutions per kilometre whereas numbers around 1500 indicate revolutions per mile. eg Alpine SIII OD speedo is either 5324/18 with 1408 revs/mile (MPH) or 5324/19 with 880 revs/km (KMH)

Cheers, Vic

 

[Wombat]

There are links to the Sceptre and other parts lists from the Rootes Post Vintage site (rootesparts dot com). Click on the "Reference Information" part way down on the left of their home page.

Good Luck!!