Vitesse vs Spitfire Steering Rack

[MarkB]

I am in the process of putting my Vitesse back together starting with the bare chassis. I have the original steering rack as well as a GT6 Mk2 and a couple of Mk4 spitfire ones. I have read somewhere that it is better to use a late Spitfire. Is this because they are quicker and is it a worthwhile modification. Theres a lot more weight over the front wheels on a Vitesse and was wondering if the Vitesse rack is geared differently for this reason. I don't want to end up with less turns from lock to lock but at the expense of heavier steering. Any advice appreciated.
Cheers

[herald948]

That's exactly it; a Vitesse (or GT6) rack is -- as I recall -- a bit over four turns lock-to-lock, while the typical Herald/Spitfire rack is something like 3.5 or 3.75 turns lock-to-lock.

[Nick Jones]

6 cylinder cars have a slightly lower geared rack (7 teeth on pinion rather than 6).

I have a higher geared Herald (Spitfire) rack in my Vitesse.  With solid rack mounts and UJ steering joint the steering is very direct but rather heavy at low speed - you'll be wanting a decent size steering wheel!  I also have 175/70 tyres on fairly offset 6" rims which won't help.

Not sure whether a later 1500 Spitfire rack is any different from the earlier ones?

Nick

[heraldcoupe]

Nick_Jones wrote:

Not sure whether a later 1500 Spitfire rack is any different from the earlier ones?

There were two suppliers of pinion gears, one type having a longer shaft than the other.
Long pinions are fairly unusual on (original) Heralds, but seem much more common on the MkIV & 1500 Sptifires.

The only meaningful difference in practice comes when fitting an uprated steering coupling. As long as you use one of the slimline pressed couplings, there is always adequate clearance with the short pinion. With the long pinion, the coupling sits much closer to the suspension turret, and in some installations some metal needs to be cut away in the turret to allow clearance.

Two different pinions were also produced for the 6-cylinder cars, but I don't know what kind of distribution they had throughout production,

Cheers,
Bill.

[Pete Lewis]

in general to identify the 2 ratio's   the 6 pot rack has a annular groove machined into the input shaft half way up the  spline the 4 pot rack is just a plain spline

faster rack on the heavy 6 pot  up front does require 3 shreddied wheat especially if you want a smaller than std. hand wheel     parking and manouvering can be totally tiresome , ours had one as reconditioner was emphatic there was only one .....wrong  

Pete  

[heraldcoupe]

peterhlewis wrote:

in general to identify the 2 ratio's   the 6 pot rack has a annular groove machined into the input shaft half way up the  spline the 4 pot rack is just a plain spline.

Is that true of both pinion lengths?
While I rarely handle 6-pot racks, I am fairly certain I have several racks with an annular groove in the pinion shaft.

Cheers,
Bill.

[Pete Lewis]

Hi Bill hope both hands are getting exercise directing the boss about !!

sorry Im not sure about the different length  pinions , and the groove I mentioned is just a fine line and not the one to clear the pinch bolt .

ive read the 6 & 7  pinion teeth changes but unless the pitch is vastly different to me the fast rack has more teeth/bigger diameter than the slow rack with less teeth smaller diameter..  how else does the  ratio change   so feel some information is a bit mixed (unless ive missed the point)  bit like the pic of bonnet height links being upside down in the manual   ha  Pete