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Dunlop 'M' Section tyres. When did they first get used?


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#1 Wakeley

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Posted 25 October 2005 - 22:56

Recently, the HGPCA (the good Lord bless 'em) decided that 'M' section tyres were not raced in period in pre '66 (i.e. 1500cc engine) F1 GP races. and so banned them from their races. I have heard mutterings that certain photos appear to exist in 1964 / 1965 that show tyres similar if not identical to 'M' section being used. This includes Stewart's Lotus at the Rand GP of 1964, photos in Sun on the Grid and the October edition of Clasic Car Africa. I think a Lotus 25 reference book also refers to that pattern in the testing data.

Unfortunately, Dunlop don't seem to be able to say one way of the other, which is a shame.

The aspect ratio was certainly larger on period photos I have seen, being more like 6.50 L 15s but as 7.00 M 13

Can anyone shed some light please? It might not change the rules within the HGPCA, after all I am flattered that someone is clearly concerned that my 1.5 litre 4 cyl FPF F1 car on 13 inch 'M' sections is going to blow his Tasman 2.7 litre away on his 6.50 L 15 inchers... (writer now removes tongue from cheek).

But, for the purposes of hisotical accuracy, were Ms around pre '66?

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#2 Peter Morley

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Posted 26 October 2005 - 11:27

It would be interesting to know when L-section tyres were first used as well.
Some early 1.5 litre F1 cars seem to have run on R5s rather than Ls.

Sounds like you have encountered the same prejudice as the 1.5 litre Lotus twin-cam cars, there seem to be more 2.7 litre 'Tasman cars' than there were engines in period, and the 'Tasman people' are worried that an engine roughly half the size of theirs might have more power than original!

#3 Wakeley

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Posted 26 October 2005 - 11:43

Agreed. As you will have seen if you were to look at the LDS thread, my obsession is with the 1961-1966 period in South Africa. Many books debate the relative merits of the white / blue spot tyres etc.. and there was the case of the tyres on the McLaren T79 being incorrect becuase they couldn't get the right tyres from one manufaturer and had to use someone else's of a different size.

#4 David Beard

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Posted 26 October 2005 - 11:46

Interesting, but could someone please post an Idiot's Guide to the various Dunlop sections, designations, etc?

#5 Catalina Park

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Posted 26 October 2005 - 11:49

The big joke is that the Tasman formula was for 2.5 litre engines! :cool:

#6 Wolf

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Posted 26 October 2005 - 11:56

DAB, I had this stashed somewhere... Is it what You're looking for?

http://members.atlas...wolf/dunlop.jpg

P.S. I would've posted it as image, but I think it's rather big for people on dial-up to load every time they enter this thread... Sorry for inconvinience. :)

#7 Peter Morley

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Posted 26 October 2005 - 11:56

Originally posted by Catalina Park
The big joke is that the Tasman formula was for 2.5 litre engines! :cool:


And they didn't want complex V engines like the stretched 1.5 litre V8s (apparently a couple did run - but as a pre-season test for 3 litre F1 where the engines were actually used).

#8 Peter Morley

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Posted 26 October 2005 - 12:12

Originally posted by Wakeley
Agreed. As you will have seen if you were to look at the LDS thread, my obsession is with the 1961-1966 period in South Africa. Many books debate the relative merits of the white / blue spot tyres etc.. and there was the case of the tyres on the McLaren T79 being incorrect becuase they couldn't get the right tyres from one manufaturer and had to use someone else's of a different size.


I've read the LDS thread with interest - at one time I had the remains of an LDS-Alfa.

I think Wolf has answered most of the questions (Wolf, where did that come from?) - of course the Tasman entrants might want more proof.......

It does suggest that most Juniors should be running on R5s.

But it doesn't make any mention of the different compounds apart from wet or dry for R5s.

By the way, I think one of the later cars (like a Lotus 33) has ran on something completely different in recent historic events.

#9 Wolf

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Posted 26 October 2005 - 12:40

Peter- I honestly do not know... : It may have been even posted here (the original name was "tech dunlop race tyre development history - f1.jpg"), or I may have picked it up on GPL related forums where someone may have posted is as source for 1965 Mod.

#10 David McKinney

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Posted 26 October 2005 - 12:45

Originally posted by Peter Morley


And they didn't want complex V engines like the stretched 1.5 litre V8s (apparently a couple did run - but as a pre-season test for 3 litre F1 where the engines were actually used).

The rationale for running 2-litre V8s in 1961/65 Historic races used to be that they were used in the Tasman Series in period...until someone pointed out that the first stretched V8s (BRMs) did not run until 1966 (and the first Climax V8 a year later)

#11 Peter Morley

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Posted 26 October 2005 - 13:05

Originally posted by David McKinney

The rationale for running 2-litre V8s in 1961/65 Historic races used to be that they were used in the Tasman Series in period...until someone pointed out that the first stretched V8s (BRMs) did not run until 1966 (and the first Climax V8 a year later)


Exactly - the early idea behind the Tasman rules was to let the locals use cheaper road based engines (or 4 cylinder racing engines like FPFs) rather than expensive racing engines, initially something like a BRM V8 would not have been welcomed. Presumably the rules were later changed to allow the racing V8s.

I think the theory is that someone ran stretched V8s in the Tasman series at the end of 1965 (e.g. their 1966 F1 spec. cars), hence they were accepted as pre-66 cars!

The 1.5 litre cars running as Tasman cars should really have been labelled 3 litre F1 cars (and running to the increased weight limit would have balanced out the huge increase in capacity).

#12 Ray Bell

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Posted 26 October 2005 - 14:15

I really don't think you've got it right at all there, Peter...

BRM were engrossed in creating their 3-litre H16, but simultaneously increased a few engines to just under 2-litres for the Tasman Cup series.

a. They never raced before 1966.

b. They were intended to race in the Tasman Cup all along, Rubery Owen having interests in the Antepodes and wanting to showpiece their showpieces in front of their customers.

c. That they raced in the ensuing F1 races was not oriiginally envisaged, I don't believe. Further evidence that their efforts were aimed at garnering Tasman Cups was shown by their greater involvement in the ensuing years, using 2.1 engines in the V8 cars and ultimately 2.5 V12s in 1968.

Additionally, I don't think you could say that there was ever any suggestion that road engines would be a part of the Tasman scenario... and they never were.

Locals were expected to... and did... snap up redundant FPFs and meet the challengers with their own FPFs head on. That the 1.5 F1 cars became so quick wasn't expected, though it must have been obvious that circumstances would ultimately change.

#13 David McKinney

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Posted 26 October 2005 - 14:19

Originally posted by Peter Morley
Exactly - the early idea behind the Tasman rules was to let the locals use cheaper road based engines (or 4 cylinder racing engines like FPFs) rather than expensive racing engines, initially something like a BRM V8 would not have been welcomed. Presumably the rules were later changed to allow the racing V8s.

Speaking as one who was there....
The formula was limited to 2.5 litres so that visiting teams and locals could continue to use their ageing FPFs (racing engines); the lesser lights used 1500cc twincams. There was an early attempt to run a V12 Maserati engine, as well as a V8 Alfa, stretched V8 BRMs and reduced-capacity V8 Repco-Brabhams. No rule change was necessary.

I think the theory is that someone ran stretched V8s in the Tasman series at the end of 1965 (e.g. their 1966 F1 spec. cars), hence they were accepted as pre-66 cars!

Interesting theory, but it never happened, at least not in a race

The 1.5 litre cars running as Tasman cars should really have been labelled 3 litre F1 cars (and running to the increased weight limit would have balanced out the huge increase in capacity).

Did any 1.5-litre cars run as a Tasman car in modern-day Historic racing? They would have qualified as 1961/65 F1 models. But the 2-litre "Tasman" cars should be regarded as 3-litre F1 cars - which would of course rule them out of the 1961/65 class

#14 Ray Bell

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Posted 26 October 2005 - 14:29

Missed the suggestion that the rules changed... of course they didn't until F5000 came in...

The Maserati was used... or at least attempted to be used... in 1966, same year as the BRMs arrived. The V8 alfa was introduced in 1968, IIRC. The Repco-Brabham V8 first appeared in 1967, didn't it?

It was expected (and publicised as happening) in 1966, but I think they were too busy getting the F1 effort going.

David's mention of the 'lesser lights' and their Twin-Cams might tend to mislead... none of these was ever seen as an outright contender, though IIRC there was one got a placing somewhere that wasn't too shabby when all the 2.5s died ahead of it.

#15 Wakeley

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Posted 26 October 2005 - 14:30

David,

Not sure if 1.5 litre cars now race as Tasman cars, but the reverse could be true where there are 2 litre Gold Star South African cars that have now been converted (supposedly) to lesser cc's such as (for the sake of a hypothetical example) a 2 litre FPF now running an Alfa 1500. As it never ran IN PERIOD as a 1.5 litre, my view would be that it should run in the 'over 1.5 litre' class i.e. in the Tasman group.

South Africa series cars, rather than Tasman cars, creates a little problem in terms of the cars it allowed to run in its own races, even before the end of 1965.

I did hear of one BRM V8 which was supposed to be 1.5 litres when purchased from someone in the UK as a spare, and when it went to Hall & Hall to be enlarged quite legitimately to 2 litres (before the ruling about 2 litres not being a Tasman spec), it was found to be oversized at 1800cc which bears out the point of engines not being 2 litres, but just a little underneath in period when run down there.

#16 Wakeley

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Posted 26 October 2005 - 14:43

Almost forgot. Big thanks to Wolf for the .JPG of the tyre list. We always 'knew' pre '66 had 'M' sections. But, the decision to remove Ms from the F1 pre '66 grid would have been easier to swallow if someone had just been up front and said "look guys, we know Ms were used in 1965, but Dunlop don't make that aspect ratio in the sizes you ran in period anymore, and we don't think 550M13s are very fair, all right?"

Instead, we were told they weren't used in period, which is now clearly not the case.

Thanks Wolf, I like having the moral ground, it looks far better from up here...

#17 Wakeley

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Posted 26 October 2005 - 15:10

David,

I thought I'd dust off the Shell Book of New Zealand racing (1963) - as you do - and just to make sure that people don't get the wrong idea of the 2.5 litre FPF restriction. I think 1963 was the last year the drivers could bring a car over 2.5 litres and run in Tasman to a (sort of) International Formula. From 1964 onwards I think, the cars had to be 2.5 litres maximum, no superchargers, and a fuel limit to 93 octane. Prior to that, the lack of 2.7 litre FPFs was more to do with the number of engines Climax were prepared initially to produce from their 2.5 litre engines, as it was fairly close to the walls.

In the final round at Teretonga that year, McLaren (Cooper 2.7 FPF) from Maggs (Lola 2.7 FPF) and Ireland in third (Ferguson 2.5 FPF).

#18 David McKinney

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Posted 26 October 2005 - 15:17

Originally posted by Ray Bell
David's mention of the 'lesser lights' and their Twin-Cams might tend to mislead... none of these was ever seen as an outright contender, though IIRC there was one got a placing somewhere that wasn't too shabby when all the 2.5s died ahead of it.

I had been going to say Peter's suggesttion of production engines being used was rubbish, then remembered the Twincams, which is why I mentioned them. They got top-six finishes (and points) on several occasions

#19 David McKinney

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Posted 26 October 2005 - 15:21

"Wakeley"...
The first Tasman Formula and Tasman Championship were in 1964
Before that the New Zealand and Australian international races were held under Formule Libre regulations

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#20 Wakeley

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Posted 26 October 2005 - 15:39

"McKinney"
Thank you for that clarification. I stand corrected. The same book (I should have read on...) says

"The introduction of what has now come to be known as the Tasman Formula was greeted with some misgivings. In the first place it precluded the use of the lightweight America V-8 engines which, in recent times, have proved extremely raceworthy when properly prepared."

I'll stick to SA matters I think.

#21 Peter Morley

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Posted 26 October 2005 - 17:58

Originally posted by David McKinney

Speaking as one who was there....
The formula was limited to 2.5 litres so that visiting teams and locals could continue to use their ageing FPFs (racing engines); the lesser lights used 1500cc twincams. There was an early attempt to run a V12 Maserati engine, as well as a V8 Alfa, stretched V8 BRMs and reduced-capacity V8 Repco-Brabhams. No rule change was necessary.

Interesting theory, but it never happened, at least not in a race

Did any 1.5-litre cars run as a Tasman car in modern-day Historic racing? They would have qualified as 1961/65 F1 models. But the 2-litre "Tasman" cars should be regarded as 3-litre F1 cars - which would of course rule them out of the 1961/65 class


I'll happily take your first hand experience over what I read somewhere.

n.b. Just read the last post - thank you "Wakeley" for finding a similar text, the version I've seen suggested it was V8s in general that weren't allowed.

I'm sure he knows the same person as I do who was rather upset to discover that his 1.5 litre BRM (which had come from a very well known driver) was 1.8 litre.

I was only repeating the justification I was given when querying the eligibility of an over 1.5 litre BRM V8 car in pre-65 F1/Tasman races and was told that some had ran before 1966 hence they were eligible.
I personally doubted that, but assumed that the experts knew better, and had at least checked their information (as I had a proper 1.5 liter car I didn't need to justify mine, hence I didn't investigate the matter further).

Not sure if I understand the last query:
Several 1.5 litre cars have ran with bigger engines in historics, in the Tasman class (some of these are of a type that never went to New Zealand), but you know that.

Incidentally I was trying to say exactly the same thing - stretched V8 cars are actually 3 liter F1 cars.

It is possible that something like a 1.5 litre LDS (e.g. one that didn't take part in the GP) running in historics has been (correctly) placed in the Tasman class rather than F1? Is that what the query was?

#22 David McKinney

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Posted 26 October 2005 - 18:17

Not quite
My query related to your saying 1.5-litre cars should run in the 3-litre F1 class - I suspect you meant stretched 1.5-litre cars?

#23 Wakeley

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Posted 26 October 2005 - 18:36

Peter.

I was placing my tongue in my cheek, which didn't work. I was trying to make a hypothetical point, but one which could happen quite easily. What do you do about a car that raced with a 2 litre engine at the end of the F1 pre '66 period in South Africa completely legitimately. It would not have been eligible even as a 1965 car for a pre '66 F1 race at the time - where does it go now in terms of class. Clearly, it's lumped in with the 'Tasman' cars.

Then the owner (let's say) places a 1.5 litre engine in the car - or the engine was in it when they bought it as the car raced 'post' '66 with the configuration at some point. The papers would state that it had an Alfa 1500 in it, and also a 2 litre FPF.

My point was that if the car didn't race in the class in period, then even if it keeps a class of engine form a later period that is in the pre '66 guidelines, which class should it be in today? It's a pre '66 car, but raced in South Africa pre '66 as a 2 litre. I'd suggest it is not a pre '66 GP car, no matter what engine it's got in it.

Luckily it's not happened yet, and do I care? Well, maybe it's linked to the issue of this chat board topic. You can 'ban' a tyre format even when it existed, but you may have cars getting in under the wire that 'conform' backwardlty. Does it matter, maybe not - but in 10 years time, it's more difficult to unravel unless someone says 'hold on a moment'.

#24 David McKinney

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Posted 26 October 2005 - 20:46

My understanding of the definition of the Pre '66 class run by the (UK-based) HGPCA is that it's open to cars of a type which raced in F1 1961-65 or Tasman in the same period. If your hypothetical 2-litre South African car is, say, a Cooper or a Lotus, it would qualify under the Tasman heading. But if it was an LDS it wouldn't - unless it followed your scenario of using a retro-fitted 1500
BTW, I'm still not sure how 2.7-litre Brabham-Climaxes qualify, as they never raced in the Tasman Series...

#25 Wolf

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Posted 26 October 2005 - 20:51

Pardon me for asking a (possibly) stupid question, but I rememer there was SA C'ship at the time- what engines did they use? If they were 2000 and not 1500cc, why not include them like Tasman series?

#26 Wakeley

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Posted 26 October 2005 - 21:44

David,

The regulations for HGPCA are not quite as you describe regarding 2.7 litre cars. Tasman appears to have wider interpretation - see Class 8 definition below from the 2004 regs, which I am fairly certain have not changed for the year just gone:

Class 1 GP cars 1925 - 1934 running on 18" or 19" wheels
Class 2 GP cars 1935 tp 1951 running on 18" or 19" wheels (cars running with smaller wheels must show period evidence)
Class 3 Voiturette cars pre 1939 of 1.5 litres on 16" wheels
Class 4 GP & Voiturette cars 1930 t0 1951 over 1.5 litres on 16" wheels
Class 5 Formula 2 cars 1952/1953
Class 6 Formula 1 cars pre 1961 on 15" wheels
Class 8 Tasman cars and Indianapolis cars pre 1961 (VSCC group 4 cars and specials at the discretion of the committee)
Class 9 Rear-engine Formula 1/Formula 2 pre 1959 cars of not more than 2 litres
Class 10 Formula 1 pre 1966 1.5 litre 4 cylinder rear-engine cars
Class 11 Formula 1 pre 1966 1.5 litre multi-cylinder rear engine cars
Class 12 Tasman and Intercontinental pre 1966 4 cylinder rear-engine cars of not more than 2.7 litres and multi-cylinder cars of not more than 2 litres built in 1965.

So, the ex-Love and McLaren 2.7 litre FPF T79 is a Class 12 car as it raced in the 'Tasman' series and won it pre-66.

In my ficticious example, a 2 litre pre '66 LDS now fitted with a 1.5 litre 4 cylinder engine would go into the Class 12 category as it never raced in period with a 4 cylinder engine. It is debateable if someone had (say) a Cooper with a 2 litre engine but reverted to a 1.5 litre in exactly the same circumstances, I'd say the same applies. Just because one chassis did something shoudl not necessarily be a reason to allow the whole load of cars to do it.

#27 Peter Morley

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Posted 26 October 2005 - 22:11

Originally posted by Wakeley

My point was that if the car didn't race in the class in period, then even if it keeps a class of engine form a later period that is in the pre '66 guidelines, which class should it be in today? It's a pre '66 car, but raced in South Africa pre '66 as a 2 litre. I'd suggest it is not a pre '66 GP car, no matter what engine it's got in it.

Luckily it's not happened yet, and do I care? Well, maybe it's linked to the issue of this chat board topic. You can 'ban' a tyre format even when it existed, but you may have cars getting in under the wire that 'conform' backwardlty. Does it matter, maybe not - but in 10 years time, it's more difficult to unravel unless someone says 'hold on a moment'.


My tongue's rarely out of my cheek but sometimes that isn't always spotted either!

A problem is they've been accepting various combinations, on what might be fairly dubious grounds, for sometime already and as we're discovering here it is already fairly difficult to unravel now let alone in 10 years time!

Accepting later cars would clearly be a mistake, if a car wasn't a pre-66 GP car at the time it never can be.

A 1.5 litre F1 car that ran in 3 litre F1 with a stretched engine is clearly a 3 litre F1 car unless the engine is put back to 1.5 litres (and any other changes, like wider tyres, reverted), accepting it as a Tasman car because it would have been acceptable is distorting history.

Accepting car types that never even ran with the larger engine is an even bigger distortion, until recently a 3 litre F1 series did not accept a car unless it had taken part in a GP - that meant that various spare cars weren't even accepted, even though they existed and ran at the time, there is no chance they would accept a car with a different engine unless it was the exact chassis.

The, supposedly 1.5 litre, 1.8 litre BRM V8 I know of was fitted in a Lotus 24 that only raced as a Formula Ford (it was a spaer car previously), it could be hard enough getting that chassis accepted as a 1.5, let alone as an over 1.5 litre V8 car (did anyone ever race a Lotus 24 as a 3 litre F1?).

As you say it is really frustrating when they won't accept something that was allowed at the time, but do accept things that didn't exist - makes you wonder if there is one set of rules for them and another for the rest of us!

#28 Wakeley

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Posted 26 October 2005 - 22:24

I have just read a really good thread (now this has got off the 'M' section question) called 'Tasman Series' in which there are some great contributions and some of the best photos I've seen of the Coopers under construction and testing at Goodwood and NZ. Made my evening they did.

But David, I may have been hasty to say it 'qualifies as a 2.7 in Class 12 as a Tasman car. Yes, it would but as a 2.5 litre! Oh dear.

Interesting though, the car as a 2.5 litre was sold (minus engine) to John Love. The engine went to Sam Tingle and was installed in the LDS '10' - and we've always had that LDS down as a 2.7 litre car. I suppose changing the stroke and pistons wasn't beyond the possible, so it probably reverted to a 2.7 FPF. According to the Love book by Mills, that one of Tingle's 2.7 litre engines (it doesn't say if it was the same one that had come out of the T79) was given to Love by Tingle for the SA GP 1967 as Love had been having engine problems.

#29 Peter Morley

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Posted 26 October 2005 - 22:25

Originally posted by David McKinney
Not quite
My query related to your saying 1.5-litre cars should run in the 3-litre F1 class - I suspect you meant stretched 1.5-litre cars?


Yes I meant 1.5 litre cars currently running stretched engines (currently called Tasman cars), as some teams ran in the early days of 3 litre F1.
Despite the fact they might have been acceptable under the Tasman formula they weren't ever built as such (and didn't exist as such pre-66), so should be classed as 3 litre F1 (where it is more likely that something similar actually ran in that configuration).

Did 3 litre F1 have a minimum capacity? If not it is possible that someone might have simply entered an unstretched 1.5 litre car - which I think you might have already asked.

#30 Doug Nye

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Posted 26 October 2005 - 23:02

Originally posted by Ray Bell
I really don't think you've got it right at all there, Peter...

BRM were engrossed in creating their 3-litre H16, but simultaneously increased a few engines to just under 2-litres for the Tasman Cup series.

a. They never raced before 1966.


Just a mo… Like much in this thread the above is almost correct. Here's how the BRM records present it...

BRM was first approached as early as 1963 by team driver Richie Ginther who was interested in the sports car potential of an enlarged version of the 1½-litre P56 V8 engine. He had a would-be backer, motor dealer Joe Vittone of Riverside, California, and in 1964 the first enlarged version of the engine – displacing 1880cc – was assembled as the first product to slot into BRM’s Project 60 folder.

Experience with the 1880cc P60 engine indicated the potential of developing one bank – 4-cyls in-line of course – as a 1-litre Formula 2 unit. This was developed for customer sale in 1965-66 as the BRM P80 engine.

Matra became a customer for the P80 F2 engines and also reached an agreement with BRM for ‘2-litre’ V8 engines to power its new MS620 endurance racing Coupes at Le Mans and in other chosen events of 1966. The initial Matra engines – still under the P60 umbrella – emerged as 1916cc V8s. This capacity was achieved by using the pistons from the 1-litre Formula 2 P80 4-cylinder engine together with the longer-stroke crankshaft adopted for the original 1880cc P60 V8.

Further work progressively enlarged what became known as the ‘Tasman’ BRM V8 engines to 1930cc, and ultimately to 2070cc. In recent years development for Hysterical racing continued some of this enlargement, and one has heard talk of 2.2/2.3-litre fakery/trickery/fudgery/thuggery/buggery of which perhaps more later…

Meanwhile, late in 1964, reversed port heads had been adopted which produced the definitive in-vee exhaust/outside inlet BRM V8 engine form, as opposed to the original in-vee inlet/outside exhaust V8 units. These heads produced what was known as the P68 or ‘Type 68’ engine form – whether in 1½-litre F1 or potential, future, enlarged-capacity form...

On October 27, 1965, the works team’s former 1½-litre Formula 1 engine serial ‘5610’ completed re-assembly in 1916cc form and was re-numbered ‘6010’ to suit. On November 8, 1965, the Parnell team’s former 1½-litre Formula 1 engine serial 5607’ was completed in enlarged form as the prototype 1930cc P60 unit, and it was re-numbered ‘6007’ to match.

On December 5, 1965, Innes Ireland finished 6th in the Rand Grand Prix at Kyalami, driving Parnell’s Lotus 25 ‘R4’ powered by the new ‘2-litre’ BRM V8 engine, ‘6007’.

On January 2, 1966, Innes ran 4th during the non-Championship South African Grand Prix at East London, driving the same car, powered by the same new ‘2-litre’ BRM V8 engine. On that occasion it chewed up the gearbox.

On January 9, 1966, the first two works ‘2-litre’ or ‘Tasman’ V8 engines – both of 1930cc capacity) powered the BRM P261s of Graham Hill and Jackie Stewart to 1st and 2nd places in the New Zealand Grand Prix at Pukekohe.

Returning to the original subject of this thread - somewhere I have some contemporary gen on Dunlop racing tyres....

Ummmmmm.... found it...

From a story I produced in 'Autosport' March 28, 1969: "The R5 (tyre) became standard wear on all Formula 1 and most other competition cars after 1960...Synthetic rubber cappings were first adopted in the R6 (CR48) tyre introduced in 1962. This L-construction tyre was based very closely on the road tyre shape of the time, its round tread being necessary to accommodate the camber changes tolerated in the suspension systems of the time. The tyres were 68 per cent profiles with 7 1/2ins wide treads on the rear sizes..."

After waffling on about the search for improved tyre stability working towards a casing which would be free from internal stresses when inflated, I described how Dunlop had told me that: "...the flat, squat-looking doughnut tyre (was) introduced in 1964...and with this M-type stress-free construction the (standing) wave barrier didn't appear until the tyre was spun up to 20 per cent higher speeds than hitherto. It ran 5-10 deg C cooler in all conditions...".

First major race for the M-section tyres then was the non-Championship 'Daily Mirror' Trophy event at Snetterton, in the hissing rain - remember? Fastest thing there was Graham Hill in the brand-new prototype (1 1/2-litre) BRM P261, on 15-inch wheels - wearing, you guessed it, old -style L-section tyres.

DCN

#31 Ray Bell

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Posted 26 October 2005 - 23:36

Of course, I should have remembered the sports car project...

To what formula was the 1965 Rand Grand Prix run?

#32 David McKinney

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Posted 27 October 2005 - 04:51

The 1965 Rand GP was run to the new 3-litre F1 regs
It's debatable whether that qualifies the 2-litre engine as a Pre 66 F1 unit, as at the time of the race the upper limit for F1 was still officially 1500cc :drunk:

#33 David McKinney

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Posted 27 October 2005 - 04:56

Originally posted by Wakeley
Class 10 Formula 1 pre 1966 1.5 litre 4 cylinder rear-engine cars
Class 11 Formula 1 pre 1966 1.5 litre multi-cylinder rear engine cars
Class 12 Tasman and Intercontinental pre 1966 4 cylinder rear-engine cars of not more than 2.7 litres and multi-cylinder cars of not more than 2 litres built in 1965.

So, the ex-Love and McLaren 2.7 litre FPF T79 is a Class 12 car as it raced in the 'Tasman' series and won it pre-66.

In my ficticious example, a 2 litre pre '66 LDS now fitted with a 1.5 litre 4 cylinder engine would go into the Class 12 category as it never raced in period with a 4 cylinder engine.

I'd forgotton about the Intercontinental part of the definition, which I think is how the 2.7 Brabhams get/got in - even though Formula Intercontinental ran only in 1961 (before there were any Brabhams...)
Never any question about the Love Cooper, inarguably a 1965 Tasman car
But I still can't see how a 2-litre LDS would qualify for Class 12, as no LDS ever ran in the Tasman Series

#34 HDonaldCapps

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Posted 27 October 2005 - 06:22

As Doug points out, the "m-section" Dunlops appeared at Snetterton in March 1964. I hesitated to mention this earlier since I had no idea that these were now referred to as "m-section" tires. You learn (or re-learn) something everyday. Glad to see that my memory is not as poor as I thought. These tires were the 'R7' if I recall, I don't remember the 'CR' code.

#35 Wakeley

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Posted 27 October 2005 - 07:04

Dear DCN,
Thank you for your recollections regarding the M Section element. I'll search out a copy of Autosport on that date. Most helpful.

Back to the (off) topic regarding the Class 12 question. The issue was not so much if the T79 would be included, but with what engine. If it is accepted with a 2.7 which it could not have competed in the Tasman series with (1964 onwards) then the only time it competed with a 2.7 would be from 1965 Rand GP onwards - whic is back to your point regarding Intercontinental races - although strictly HGPCA regs should perhaps make 'Gold Star' races in SA another element to remove the avoidance of doubt. This places any theoretical 2 litre SA car (e.g. an LDS so equipped) in the same boat if it raced pre '66 with a non F1 regulation power plant as defined at the time.

For a number of cars that appeared in the 'last' pre '66 race at the Rand GP on 4.12.65 this was probably not a problem if they had run elsewhere before this race with a 1.5 litre engine (either V8 or FPF etc..). This race got described in Sheldon (SA Record 1960-75) as 'the first of the Intercontinental race with the most popular power unit being the old Formula 1 4 cylinder Coventry-Climax engine enlarged from 2.5 litres to a maximum of 2.7 litres'.

Cars that appeared:
Brabham BT11 F1-2-64 FPF
Pretorius Lotus 21 21-952 FPF - Drove this car, not LDS
Bonnier Lotus 25 25-R6 FWMV
Siffert Brabham BT11 F1-6-64
Ireland Lotus 33 33-R13 BRM '56'
Hawkins Lotus 25 25-R7 FPF
Charlton Lotus 20 20-J-867 Lotus LF (did not start, engine failure)
Prophet Lotus 24 24-P2 (estimated) Maserati 250S
Anderson BT11 F1-5-64 FPF
Love T79 FPF
Jeffries T55 F1-11-61 FPF (previous Love car)
de Klerk BT11 IC-5-64 FPF
Tingle LDS FPF (2.7)
Pretorius LDS - Reserve car for Lotus 21 did not start
Serrurier LDS FPF (2.0)
Puzey Lotus 18 18-P2 (estimated) FPF
Holme LDS '5' Lotus LF (1.5)
Niemann Lotus 22 22-J-37 Lotus LF
Hume LDS FPF (not sure) Did not start

#36 Peter Morley

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Posted 27 October 2005 - 09:27

Originally posted by Wakeley
Dear DCN,
Thank you for your recollections regarding the M Section element. I'll search out a copy of Autosport on that date. Most helpful.

Back to the (off) topic regarding the Class 12 question. The issue was not so much if the T79 would be included, but with what engine. If it is accepted with a 2.7 which it could not have competed in the Tasman series with (1964 onwards) then the only time it competed with a 2.7 would be from 1965 Rand GP onwards - whic is back to your point regarding Intercontinental races - although strictly HGPCA regs should perhaps make 'Gold Star' races in SA another element to remove the avoidance of doubt. This places any theoretical 2 litre SA car (e.g. an LDS so equipped) in the same boat if it raced pre '66 with a non F1 regulation power plant as defined at the time.

For a number of cars that appeared in the 'last' pre '66 race at the Rand GP on 4.12.65 this was probably not a problem if they had run elsewhere before this race with a 1.5 litre engine (either V8 or FPF etc..). This race got described in Sheldon (SA Record 1960-75) as 'the first of the Intercontinental race with the most popular power unit being the old Formula 1 4 cylinder Coventry-Climax engine enlarged from 2.5 litres to a maximum of 2.7 litres'.


DCN's information on M-sections means they were available for at least a year before the formula ended, that must be a very strong case for their acceptance on a car that ran in 1965.

His information also confirms that no stretched V8 engine ever ran in a Tasman race - which I think had already been established.

Perhaps you could offer a compromise - M-section tyres in exchange for them keeping their definition of a Tasman car..........

At one time the regs did mention SA Gold Star races - not sure when/why that dropped out (the impression given was that Gold Star was 1.5 litre - did it change or did they drop it when they discovered it was 2 litre?).

Wasn't the idea behind the Intercontinental formula that the teams wanted to continue with their 2.5 litre cars rather than move down to 1.5 litres and started the formula in the hope that 1.5 litre would fall flat on its face?
Did the IC rules suggest an increase in capacity when the authorities were proposing a decrease?

CR code refers to the tread pattern - CR48 was a wavy pattern, CR65 was more of a block pattern - one of the tyre suppliers lists shows these tread patterns.

#37 Wakeley

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Posted 27 October 2005 - 10:05

Peter,

I am nervous of offering opinions based on my groaning bookshelf, rather than on people who were there or know better. So, at the risk of being wrong, the Sheldon book prefaces the start of the 1965 (not 1966) race year by stating:

'South Africa anticipated the rest of the world by changing to a 3 litre limit for their Championship at the beginning of 1965. However, the South African GP, as a World Championship qualifier, was obviously run to the 1.5 litre Formula and is included at this point for convenience.'

The next section of the book (page 121) starts with the following (Wakeley Note: Bear in mind the dates the book deals with of 1960 - 1975 in terms of the definitions written after the fact)

3.0 Litre Formula
---------------------
Cars limited to 3000cc capacity unsupercharged, 1500cc capacity supercharged
Cars complying with International Formual 2 admitted 1965 - 1975
Cars complying with International Formula 5000 admitted 1968 - 1975

To a previous question, no note of a minimum engine capacity, but this is an abstract, maybe there were minimum limits.

So, the first race under the '3.0 litre rules' at the II Cape South Eastern Trophy on 9.1.65 indicates that Love altered his T55 FPF engine to 2 litres, but many others probably remained at 1.5 litres, it is not clear from the book - do others know differently please?

As to the tyre issue back in the present, I think the problem is that the aspect ratio of the tyres in question that are available now as 'M's are different. C'est la vie.

#38 David McKinney

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Posted 27 October 2005 - 11:16

Originally posted by Peter Morley
Wasn't the idea behind the Intercontinental formula that the teams wanted to continue with their 2.5 litre cars rather than move down to 1.5 litres and started the formula in the hope that 1.5 litre would fall flat on its face?
Did the IC rules suggest an increase in capacity when the authorities were proposing a decrease?

Yes, yes and yes
Engine limit was 3000cc

#39 HDonaldCapps

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Posted 27 October 2005 - 11:46

Actually, there were some options that were adopted for the Intercontinental Formula for 1962, which the CSI approved, as I recall, pushrod/stockblock engines getting a displacement of something that I cannot remember off the top of my head. Although the ICF was dead in Europe for 1962, the USAC had ICF as one of the options for promoters of its RRC events that season, hence the cars seen at Bossier City and IRP as examples. So, ponder that for a bit. I might be lucky enough to have brought a copy of that information along with me in electrons, otherwise it is 10,000+ miles away. It would seem to be that you could not run the Scarab Buick in any Class since it does not seem to fit any of the classes listed....

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#40 David McKinney

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Posted 27 October 2005 - 12:21

Wasn't the Scarab-Buick built for Formula 366?

#41 Ray Bell

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Posted 27 October 2005 - 12:35

Now David, is it fair to bring that up?

Somebody might now need to decide where that fits into the modern groupings...

#42 Peter Morley

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Posted 27 October 2005 - 13:37

Originally posted by Wakeley
Peter,

I am nervous of offering opinions based on my groaning bookshelf, rather than on people who were there or know better. So, at the risk of being wrong, the Sheldon book prefaces the start of the 1965 (not 1966) race year by stating:

So, the first race under the '3.0 litre rules' at the II Cape South Eastern Trophy on 9.1.65 indicates that Love altered his T55 FPF engine to 2 litres, but many others probably remained at 1.5 litres, it is not clear from the book - do others know differently please?

As to the tyre issue back in the present, I think the problem is that the aspect ratio of the tyres in question that are available now as 'M's are different. C'est la vie.


I know all about groaning bookshelves, I've got magazines & books spread over 4 different locations! As you say first hand experience should be preferable to written accounts, but neither are infallible, photographs are best - but when you see what can be done on a computer you could even question them.

Whenever I've queried the difference in tyre widths between period and now I've always been told that Dunlops are the same dimension as original. As the list shows, the discrepancy is probably because the cars in question ran R5s and now use L sections (as per original according to the powers that be!).

Is your problem that they don't make the specific size that your car ran in period?
Or are they querying the dimensions of current Dunlop M racing tyres - in which case I would suggest they verify the dimensions of their L tyres first.

In the end the problem is that historic racing does not have to recreate events as they happened in the past, it is about racing old cars but with a new set of rules applied to them. A series organiser isn't obliged to follow the original rules, and basically has a free hand with the rules.

#43 HDonaldCapps

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Posted 27 October 2005 - 13:53

Originally posted by David McKinney
Wasn't the Scarab-Buick built for Formula 366?


Nope, the rear-engined, open-wheeled Scarab Buick was intended for ICF and the big honking Ol' Yeller/Max Balchowsky type Buick crammed in one of the original Scarab GP cars could have been used in Formula 366 had it gotten off the ground. I think Karl drove this car at Riverside and wrote about it for C/D.

The ICF Buick displacement was in the 4000cc neighborhood as I recall, or whatever the limit was for the pushrod/stockblock ICF engines. ICF for 1962 retained the 3000cc limit for racing engines, hence the number of 2700cc FPFs floating around the USA since they could be used for both ICF and sports car racing.

#44 Ray Bell

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Posted 27 October 2005 - 14:00

Yes, very close to 4000cc I recall...

There are some nice pics of that car around here somewhere. John Ellacott pics, now where are they?

Well, here's one:

Posted Image

#45 David McKinney

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Posted 27 October 2005 - 14:48

Originally posted by HDonaldCapps
The ICF Buick displacement was in the 4000cc neighborhood as I recall, or whatever the limit was for the pushrod/stockblock ICF engines.

Although no ICF races were run in 1962, no doubt regs were published. I would have thought however that the upper limit for pushrod/stockblock engines was the same as in 1961, ie 3000cc

#46 Ray Bell

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Posted 27 October 2005 - 15:35

Hmmm... I thought it was bigger in 1961...

I've definitely seen the different sizes somewhere.

#47 HDonaldCapps

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Posted 27 October 2005 - 17:27

Originally posted by David McKinney
Although no ICF races were run in 1962, no doubt regs were published. I would have thought however that the upper limit for pushrod/stockblock engines was the same as in 1961, ie 3000cc


Ah, David, just because no ICF events were run in Europe doesn't mean that ICF didn't exist. The Pipeline 200 at the Hilltop Raceway outside Bossier City, Louisiana was announced as a “Formula Libre” event, but also stated that those cars participating has to conform to either the current Formula 1 (1,500 cc), the Intercontinental Formula (3,000cc/5,000 cc), or the USAC sports car regulations (up to 8,000 cc). The same went for the Hoosier Grand Prix at Indianapolis Raceway Park.

As for ICF 1961, there were no distinctions as to engine configurations or origin, only a maximum displacement of 3,000cc normally aspired.

All this was laid out in several of the American magazines of the time, SCG and C/D being two that I know devoted some space to the new ICF regs for 1962.

#48 David McKinney

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Posted 27 October 2005 - 18:28

Thanks for bringing those US races up, Don
I didn't realise they still called the relevant class Inter-Continental :blush:

#49 HDonaldCapps

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Posted 27 October 2005 - 18:43

Originally posted by David McKinney
Thanks for bringing those US races up, Don
I didn't realise they still called the relevant class Inter-Continental :blush:


David, it was news to me as well when Bill Green at the IMRRC pointed it out to me..... :blush:

#50 D-Type

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Posted 27 October 2005 - 21:44

Of course the correct thing to do would be to say that if the chassis is 1965 or earlier then they are eligible for pre-1965 but all cars with oversized (>1.5litre) Climax and BRM V8s had become 1966 Formula 1 cars and should meet the 1966 minimum weights.

But this whole business is a bit silly - how many ERAs were 2 litre in period? Certainly neither E-type was. How many D-Type Jaguars had 3.8 litre engines outside of the works and Ecosse ex-works cars? Did the Tojeiro-Jaguar ever run a 3.8; in fact didn't the Ecosse one only ever race as a 3 litre? How many Lotus XIs and XVIIs, Lola Mk 1s or Elva Mks 3 or 4 had 1212cc Climaxes in period? They were nearly all originally 1100s with the occasional 1500. A35s, Morris Minors and Mk1 Sprites should be 948cc and Mk 2 Sprites and Midgets 1100cc - not 1275. Triumph Spitfires should be 1200cc except for the last one which was a 1500 as was the final Spridget. Anglias should be 997cc or 1.2 litres not 1500cc - let alone 1650cc. Mk 1 and Mk 7 Jaguar saloons, XK120s and XK140s should be 3442cc while Mk2s, Mk VIIIs, MKIXs and XK150s were 3781cc. etc, etc - that's off the top of my head without checking. I'm referring here to their original capacity and accept that after going into club racing, some of the capacity increases were made more or less in period.