SS saloon differential ratios

(bobson) #1

Dear all, i’m working on a prewar SS saloon rear axle fitted to a racing special, and i’m not sure if it’s originally from a 2.5 or a 3.5 but it is definitely the wide-track one from a 6-cylinder saloon. The owner is looking for a taller ratio to suit the circuits he races on.

Could anyone tell me what the rear-end ratios were originally for 2.5 and 3.5 SS saloons? Thanks
Bob

(Ed Nantes) #2

They were generally 4 .25 and 4.66 : 1. Although other ratios could be supplied to order. My saloon1937 model was ordered witha 4;1 difff ratio from a 2 1/2 SS100
2 1/2 litre SS100s had a 3.77:1
This is all assuming it is an EnV back axle
If so it is possible to fairly easily adat a post war Hypoid ENV diff assembly in but once again I think about 3.7 is as high as it gets.
I’m not sure about the significance of " wide track’ as they were basically the same as SS 100s But post war Salisbury axles from MK IV wre wider.

(Peter Scott) #3

I think the normal 2.5 litre SS saloon has a 4.5:1 ratio. Because of the simple ratio it’s easy to check what your axle has by turning the input shaft four and a half turns.

I see https://www.vorcomp.co.za/rear_axle.htm does a 3.8:1 crown & pinion set.

Peter

(bobson) #4

That’s a great help guys! It’s roughly a 4.5:1
Now i know what the options are for different ratios (and by wide i meant it’s not the smaller 1.5 litre)
& thanks Pete for the link to Vorcomp, they have some nice bits there