Tires

[awilliams]

I'm long overdue for new tires on my Ace Bristol.  I am currently running Dunlop race tires on 15" wheels which fill the wheel wells and look great but are totally unsuited for a road going Ace.  My question is, is there a 15" tire that not only works well but is tall enough to fill the wheel openings or will I have to go to 16" wheels?
   
   On another note, can anyone explain the difference between a D and a D2 Bristol engine?  My understanding is that the only difference is 9:1 pistons as opposed to 8.5:1 but I'm not sure this is accurate.

[B.P.Bird]

I have found the new radial Blockley 205 VR 70 15 to be very good with the leaf spring chassis. I believe you are correct in saying that the only difference between the 100D and the 100D2 is in the CR.

[AK1055]

Barrie,
   
   Are you referring to road use or have you used these for hillclimbs or sprints?
   
   Does anyone have experience of the Avon CR6ZZ which are available in various 15" size from BMTR Birmingham? There are generally a soft compound in the larger widths but they do a slightly harder compound in the narrow widths.
   
   I use the softer compound on my Mk IV Cobra which perform superbly on the road as well as for hill climbs & sprints.
   
   Malcolm

[awilliams]

Thank you for the information.  I checked with Blockley and they recommend either 550x15 or 165VR15 for a radial.  Does anyone have any experience with either of these tires on an Ace?

[AC Ace Bristol]

Andrew.
   
   5.50/5.60 by 16 were standard tyre for the Ace Bristol and a 15 inch option was available from mid 1957, During the past 12 years I have run dunlop racers on the road and track until Avon and others reintroduced 16 inch tyres. Then the change to Avons proved better on the road in all conditions especially in greasy wet conditions.
   
   John Arnold run 15 inch Avons on his Ace and they were very good on both road and track, however I believe they too were 5.50 /5.60 wide (165mm) some Aces run 175 or even 185mm tread width but I would have thought they would burn the paint off the rear wheel arches asumming they would ACtualy clear,  Barrie referes to 205mm lower profile, they would extend beyond the standard  Ace bodywork, unless you have modified to lipped bodywork/ arches as per 260/289 Cobra, these were designed to cover the standard 15 inch by 5.5 or 6 inch rims as suppliued by AC Cars " Thames Ditton". 185 x 15 inch with 70% profile.
   
   Andy Shepherd and a few others run 15 inch wheels on their Ace Bristol's, will have a word and pass on their comments.
   
   The Ace requires a softer walled tyre, not sure if the Blockley is the most suitable for the Ace, great on earlier cars and very good with XK 120/140 jaguars, however they are heavier and more touring than Sport..[;)]
   (Personal opinion. Hopefully not putting noses out of joint)..[B)]
   
   Keith.

[Laurence Kent]

My car runs on Coker 185 X 16s. I seem to have to check the tyre inflation with some frequency, but these tyres are good for both the street and racing. They never rub against the body, unlike other 185s, such as the Pirellis. They also give the Ace a nice look...still a bit on the slim side, but not that ultra-skinny look one gets with 155s.
   
   As for difference between the 100D Bristol motor and the 100D-2, I remember reading--but I can't remember where--that the D-2 also had a stronger bottom end. I remember that this was characterised as "a nod" to racers...who wanted to get their cars into a higher state of tune.

[awilliams]

Thank you Keith and Laurence.  I appreciate the advice.  While I like 16" wheels, I'd rather not go through the expense of getting new wheels unless absolutely necessary.  So, it would be good to hear about some 15" tires that work as well.
   
   Can anyone confirm Laurence's comment about D-2 emgines having a stronger bottom end?