Technical Tips for the 346 and Star Page 4

Advice and guidance for the maintenance of Armstrong Siddeley cars. If you have other technical advice for Armstrong Siddeley owners you would like to share here, please contact sphinx@siddeley.org

Please note, technical tips are given by individual members and ASOC Ltd does not warranty the accuracy of them or endorse them in any way.

More tips can be found by using the links to the right.

Choosing tyres for your 346 (or Star) - Supplied by Keith Dewhurst

The original tyres for the 346 were 670x16 crossplies, although the factory did issue guidance on fitting Michelin X tyres. I have driven a 346 on crossply tyres made by Firestone and found the ride very good and steering light, but found road-holding and sway on bends, and the level of wander quite unacceptable compared to the radials I had experienced previously on the same car. I am therefore very much in favour of radials being used, especially if the car is to be driven in a modern way for general motoring. By the way, I have also driven a 346 fitted with taxi tyres and it greatly scared me on even moderate bends !!

The closest and I believe correct radial size for the rims is a 185x16x70(profile). A 346 has a top speed of around 100mph, so the tyre should be speed rated accordingly. If it is not rated for the top speed of the car it is possible then your insurance might be invalid.

Suitably-rated 185 size tyres are only generally available in the UK from specialist suppliers, and many owners have fitted 195, 205 or even 215 tyres. These sizes are more commonly found as they are used on modern 4x4s. Owners using these sizes seem to be quite satisfied with them. However, it is possible that the rear tyres may foul the spats on cornering and be too wide to fit in the tray for the spare tyre in the boot. Tread patterns can also be rather aggressive in looks and give rise to intrusive road noise at speed.

The 185 size which I feel best suits the car also fits some Jaguars, Jensens and other quality cars of the 1950s. When fitted to a 346 I use a pressure of 30psi for the front and 32psi for the rear for normal loads. I find the 346 likes the rear tyres to be a couple of pounds higher than the front. Around 6 types of tyre are available in 185x16, each with its own pros and cons.

Michelin make 2 types: A reproduction of the original Michelin X tyre which looks superb on the car having a rolling diameter close to the original crossply. However, it is inevitably older tyre technology and although superior to crossplies in road behaviour, I think it has poorer road holding than a modern radial and makes the steering rather heavier than a modern radial does.

Michelin also make the Michelin Pilot X. I have no personal experience of this tyre nor have heard anything of it from any user. I would think it ideal for the sporting driver of highly tuned cars as it has a very high speed rating. It also has a good high profile and is modern tyre technology. However, I feel sporting driving is unlikely to be our priority!

The Vredestein Classic, made in Holland I believe, is I think a very good compromise. It has only a slightly lower profile than the Michelin X and looks well on the car. The ride is perhaps slightly harsher than the Michelin X, but in all other respects it offers classic looks with modern tyre technology and therefore grip. It is also amongst the middle to lower price range! It is what I have used for some years now.

Also available is the Avon Turbosteel. I have used these and they are a nice riding tyre and I would recommend them to you over the Vredestein, except they are of a considerably lower profile than original tyres and do not in my view look good on the car.

Pirelli make an excellent tyre the Pirelli Cinturato. I have driven a 346 on these and they are superb. Although an older design in every respect I found them to be without flaw. The drawback? Well when last I enquired they were considerable over £200 each, about double the cost of the Vredestein or Michelin X tyres.

Finally Avon makes a crossply tyre called the Avon Turbospeed. This is a well known and well respected tyre, said to offer close to radial performance. I think Rolls and Jaguar drivers often fit these. Sadly I have no experience of driving on these, but if you want to stick with crossplies, then I think this is certainly the one to go for – and if you do choose them, I would very much like to hear your thoughts on these tyres.

So to sum up: If the choice is for radials, then personally I would go for either the Michelin X, if originality was my priority or for the Vredestein Classic if best overall performance and grip was my priority. If money is no object then the Pirelli Cinturato would be my choice. If crossplies are for you, and light steering may be your priority, then have a look at the Avon Turbospeed, I suspect these would turn out to be very good in use.