Caster angles, toe in, toe out

[Acoc-06915]

I notice my greyhound has heavier steering than my Bristol 400 which is of course slightly heavier.  The centering is also less effective.  I have been told that this is quite normal and some owners have the front wheels adjusted to toe out slightly to improve the centering.  I would be really interested to hear any views or advice regarding this topic.

Michael

[Flyinghorse]

I have a few general observations ( also being a 400 owner and having recently worked on an Ace )
I would start by getting the actual ( on your car) caster/ camber/ toe readings measured so you have a reference
Hopefully a Greyhound owner will provide factory settings and possibly other advice.
The Bristol 400 has 3 1/2" rims and quite narrow 5.5 tyres, so greyhound will have larger tyres which increases the issue at low speed.
Check inflation pressures - often the lower pressures we run on older classics (25-28psi) exacerbates the heavy steering.
I would also put some swivel plates / tunrntables under the front wheels and check with that if everything turns as freely as it could also simply be lack of greasing on the rotational front suspension components.
Regards
Graham

[Flyinghorse]

One other thought , and this is why important to check actual caster angle, as the uprights can get reversed / swapped side to side causing an issue with the camber.

Ideally you want a positive caster  to what ever the factory spec is . I think caster won't be adjustable as built into the actual upright.

From what I have read the caster has the biggest impact on self centering.

[Acoc-06915]

Thanks Graham. Some useful points there.  My particular greyhound was fitted with Cobra wheels in the sixties and that I would think would make the steering a bit heavier .  They do look lovely though.

I am going to thoroughly lubricate and check tyre pressures.  What range of pressures would you look at?

Speaking to IN racing he agreed that his Greyhound had steering heavier than his 400.

Many thanks so far.

Michael

[Flyinghorse]

Michael,
I don't know what  tyre pressures are recommended( and I'm surprised no current/ previous Greyhound owner has chipped in), but my previous suggestion re running lower pressures will likely be in correct as the tyres you have on Cobra rims are likely radial not cross plies.

Longstone say on Michelin x radial 33psi is a good start point for a Greyhound- see the find your car features on their website.
Their article on the Ace tyre pressures interesting reading as does the Cobra tyre section.
As always depends on what your tyres actually are and your driving style and road types.
https://www.longstone.com/ac-ace-tire-pressures#:~:text=Crossply%20tires%20on%20the%20AC,for%20their%20particular%20AC%20Ace.

[B.P.Bird]

Michael,
The front wheel geometry you enquire about is to be found on page 47 in the AC Greyhound General Instructions.
If you don't have the General Instructions you are placed at something of a disadvantage and I note that the A.C. Owners' Club do list the Greyhound General Instructions as one of their handbook reprints. In any event here are the settings:

Toe In 1/16" to 1/8"
Camber Angle 30' to 1°
Caster Angle 6°
King Pin Inclination 9°

Only the toe in is adjustable and you might note that, although the trunnions and vertical links are Alford and Alder parts (A&A) also used on the Triumph TR2-5, A.C. used a different caster angle and therefore the trunnion at the bottom of the vertical link was modified by re-machining and setting the wishbone pin at another angle to suit. The components will not fit on the wrong side. A great relief for numpties like me.
It is a long while ago, when I was young and strong, but I do not recollect the steering being heavy on '2535 even when I too swopped the 5" rims for 6" rims. It was heavier on the 16" wheels with Michelin X, but that was an option which Mr. Charles insisted on in spite of Alan Turner having specifically designed the G'hound for 15" wheels.....
The other important variable in the question of steering weight is steering ratio. The steering was quite quick on the G'hound and it might well be that the steering on the Bristol 400 is lower geared ?
Finally I did find the steering and roadholding sensitive to tyre manufacturer. The best tyres I found were B.F.Goodrich Comp T/A. However that will no doubt, by now, be a different specification. Probably best to canvass current G'hound drivers for their views on tyre choice.
Barrie

[Acoc-06915]

Thank you both for sharing your knowledge, really useful.  I realised when trawling through the history file that I do have the AC instruction book which I have to say will come in handy if I decide to rebuild the gearbox, but certainly contains plenty of useful info and data.

So far I have checked and greased the numerous points on the front suspension and noted that the steering turns lock to lock nice and smoothly which is comforting, also all the rubber type bushes are good.  Next I will check the tyre pressures and tyre manufacture.  From memory I think they are Avon radials.

Whilst writing, are new disc rotors available anywhere or can they be skimmed as I feel under braking a very slight judder consistent with slight run out of the discs.

Michael

[Acoc-06915]

TYRE PRESSURES.

I have checked and the tyres are Avon Radial steel 185 R15 and set at about 27psi all round.

I would be interested to have views on tyre pressures before I start trying anything different.

Michael

[Flyinghorse]

I can't comment on the tyre pressures ( except longstone say 33psi but is for Michelin x) but I recall a mk2 Jag I bought had really bad toe out and was very heavy on steering and centering.
It was so bad it was visible but I recommend checking yours. Years ago I bought the kit to do wheel alignment ( turntables/ Dunlop caster camber) and this has been excellent if you don't have a garage near you
www.trackace.co.uk

I'm up in Scotland where none of this is easy unless you have own equipment.
Regards
Graham

[Acoc-06915]

Finally managed to get the Greyhound to Baskervilles and the toe out was "off the clock" so hopefully will give better castor and a lighter feel.  Unfortunately whilst in the shop we found that the silicon fluid had done for the master cylinders and the servo.  I should pick it up this week and will report back.  Fingers crossed!

Michael