Group 2/Group 1/Group A Anom(a)lous Cars

[Al Weyman]

Can anyone explain to me how the 2nd Gen big block all aluminum engined Camaro raced by Frank Gardener was ever remotely legal? They never even made such a car at least not properly, they stuffed a few engines in the chassis (about 50 odd) in a none GM garage workshop only sold about 20 odd of these and broke the others for the engines to race in CanAm cars so how were they ever homologated for circuit racing as i believe the original homologation was for the drag strip, I'm confused??

[Clive Brown]

Originally Posted by Al Weyman

Can anyone explain to me how the 2nd Gen big block all aluminum engined Camaro raced by Frank Gardener was ever remotely legal?

Now I'm glad you asked that, Al! The ZL1 Camaro was a factory production option on the first generation Camaro, and was aimed at the Superstock class of the NHRA, for which the minimum production number was 50. The Camaro was already available with the alloy-headed but iron blocked 427 L88 motor, but Chevrolet introduced into limited production a motor based on that used in the Chaparral Can-Am car. I'm not sure if the heads were the same as the L88 or not.

In all, Chevy produced 69 Camaros fitted with the alloy big-block motor, which weighed about the same as the stock all-iron 327. The motor was also made available as a production option for the Corvette; two were made.

I believe that for Group 2 homologation at the time, it was only necessary to produce a certain number of parts kits; they did not have to be fitted to cars off the production line. However, I thought the minimum quantity was 100. Also, the motor was never sold in a second-generation car, so just how Frank's car got its homologation I do not know.

If the homologation was dubious, how come Ford to name but one competitor did not ask the question of the FIA at the time- although I'm not sure how dry-sumped, mechanically fuel-injected 1litre and 1300 BDA Escorts got in , either.

Later, of course, we had the farce of Group 1 Avengers with twin 40DCOE Webers, and the Mazda RX7's acceptance as the saloon car it so clearly wasn't....

[Peter Mallett]

Posts moved from BTCC Supertouring thread.

[historic racer]

Originally Posted by Al Weyman

Can anyone explain to me how the 2nd Gen big block all aluminum engined Camaro raced by Frank Gardener was ever remotely legal? They never even made such a car at least not properly, they stuffed a few engines in the chassis (about 50 odd) in a none GM garage workshop only sold about 20 odd of these and broke the others for the engines to race in CanAm cars so how were they ever homologated for circuit racing as i believe the original homologation was for the drag strip, I'm confused??

I think you will find that it was listed as a variant on the homologation papers, which I again think required only fifty to be produced. I raced in the same series and certainly nobody questioned its use, mind you as Clive said, Ford's were busy sliding in 1300 BDA Escorts under the same allowances.

[GORDON STREETER]

I assume you mean "anomalous" Al (and that's after most of the day in the beach bar) !
Anyway it used to happen in those days and was probably to do with "who knew who"

[Clive Brown]

Aaah.... but what if the second generation Camaro was itself homologated as a production evolution/variation of the first generation car, rather than as a completely new vehicle?

Surely someone out there has copies of the FIA homologation papers for a second generation car? At least the ZL1 motor never made it into Group 1!

Incidentally, if anyone should happen to have the odd spare ZL1 motor or so gathering dust in a lock-up or under a bench, I know a gentleman from Watford who will take it off your hands for the right price....

[Frank de Jong]

While it was not unusual to have homologations moved from first to second generation (like the Escort II) the ZL1 Camaro was in fact a homologation variant (9th addendum) of the Mk2 Camaro. (#5310). It was for group 2 only.

[Mike Bell]

Originally Posted by Clive Brown

Incidentally, if anyone should happen to have the odd spare ZL1 motor or so gathering dust in a lock-up or under a bench, I know a gentleman from Watford who will take it off your hands for the right price....

Al is looking for one as well....

Clive, you have far more period knowledge than I do, but as far as I can remember the 1973 Gp2 BTCC regs allowed alternative cylinder heads, so Ford simply fitted a BD head to the 1300GT?

[Al Weyman]

Originally Posted by GORDON STREETER

I assume you mean "anomalous" Al (and that's after most of the day in the beach bar) !
Anyway it used to happen in those days and was probably to do with "who knew who"

Ask Peter he split the thread, I don't have a clue what it means either!

[Clive Brown]

Mike

As far as I know, the 1973 Group 2 regulations for the RAC British Saloon Car Championship most certainly did not allow alternative heads; you were permitted to remove metal from the homologated head, but not add it.

Perhaps you are thinking of the Group 5 regulations under which the Championship was run up to the end of the 1969 season? This allowed 8 port heads on Minis, and downdraught heads on 1300 MAEs in Broadspeed's 1300GT Escorts.

I also think that whilst the bore on a Gp.2 homologated motor was free, the stroke was not; that was why Ford homologated the RS3100, to allow the longer stroke that gave them 3.4L in the Essex-based Cosworth GA.

As a guess, I'd say that the 1300 and 1litre BDAs were homologated as a production variation of the RS1600, which was a genuine production entity, albeit in what sort of numbers I'm not sure.

[Al Weyman]

I thought the RS3100 was a merely a 60thou overbored Essex.

[Clive Brown]

Originally Posted by Al Weyman

I thought the RS3100 was a merely a 60thou overbored Essex.

You may be right Al, but I thought that the whole point of the RS3100 was to allow the longer stroke, which coupled with an overbore, gave the 3.4 litres.

I can still remember Frank's Camaro leading all the factory Capris and BMWs at the Silverstone TT in 1973.

There ain't no substitute for cubic inches....

[Al Weyman]

Have you seen Frank's video where he is first instructing people how to drive the beast around Oulton then goes to a BTCC race at Thruxton? The speed differential between the Camaro and the Capris and Batmobiles is quite stunning.

[brown dog]

I believe that Group 2 DID allow alternative cylinder heads. The RS3100 (Group 2) Capri obviously had the Cosworth 4 valve heads, and the earlier RS2600 Capri (Gp. 2) had Weslake designed heads.

My understanding of the RS3100 engine size is this. The RS3100 road car (the "homologation special") was merely a 3000GT with a 0.060" overbored engine, and a very mild porting job (I know one of the people who was involved in building these "special" engines back in the day, and they were certainly not that special!) The original Capri 3000GT engine was 2994cc, which meant they ran in the up to 3L class. The RS3100's 3.1L capacity allowed them to run in the next class, up to 3500cc, so they could stretch the engine and be competitive with the 3.0CSL, which was 3500cc and now sporting a 4 valve head too. The engine bore went up from 95.2mm of the RS3100 to 100mm on the GAA engine, giving a capacity of a tad over 3400cc.
Of course no road going Capri was ever produced with such an engine, but there were 100 Cosworth engine kits produced (or 200 depending who you talk to?) so obviously not necessary for them to be fitted to the road car from the factory, as was necessary in the likes of Gp.A. But engine capacity in the original car did matter in Gp.2, hence building the overbored RS3100 road car. My guess is the 1300BDA Escort was running as a 1300GT, as someone suggested earlier.

How all of this would extrapolate into the OP question re the rank Gardner Camaro I am not sure, was there a big block Gen II Camaro produced ex factory?

[Frank de Jong]

The last post is correct; alternative heads had to be produced 100 times to be homologated. For the BMW 2002 there were 2 totally different 4-valve heads.
The 1300 BDA was a 1300 engine with again a 4-valve head; it was homologated in 1000 cc form (very early IIRC) and even 1150 form. Ford did its homework.

[Peter Mallett]

IMO the 3100 RS Capri was developed for two reasons, the first being the engine size and in reality it didn't need to be a very hot engine, they just needed the bore and stroke. The other reason was the ducktail. The RS 2600 (in reality a 2900) was found to be unstable at speed so they needed that ducktail to compete with the BMW.

But in fact there is nothing "anomalous" about these cars.

The XJS and the RX7 are arguably the most strange cars to be granted Group 2 homologation, (the XJS went on to Group A). What others were there?

[Alex E]

They were certainly allowed 4 valve heads in Gp 2 in 1973. I think it was just that the most known examples, Capri , BMW did not have them ready for use until 1974.
As I remember the bore size was free, only the crank stroke had to be homologated with a production car, or evoloution of. Hence the RS 3100 and the CSL Batmobile.
Alex

[Al Weyman]

Yes the 2nd gen Camaro was produced and quite a few as well with a 396ci big block engine in fact I believe it was a 402 but released as 396 for insurance purposes and also understated bhp. But it was an all iron engine and although powerful was a real heavyweight.

[Greg Cozier]

Originally Posted by Alex E

They were certainly allowed 4 valve heads in Gp 2 in 1973. I think it was just that the most known examples, Capri , BMW did not have them ready for use until 1974.
As I remember the bore size was free, only the crank stroke had to be homologated with a production car, or evoloution of. Hence the RS 3100 and the CSL Batmobile.
Alex

The bore size wasn't free, you were allowed to bore up to the class limit. The RS2600 Capri could only go to 2999cc, the homologation special RS3100 could go to 3500cc (10cm pistons). As mentioned above, the duck tail was the only other bit added for the RS3100, the GAA cyl heads were part of the 'kits' that had to be made 100-off.

[Alex E]

Originally Posted by Greg Cozier

The bore size wasn't free, you were allowed to bore up to the class limit. The RS2600 Capri could only go to 2999cc, the homologation special RS3100 could go to 3500cc (10cm pistons). As mentioned above, the duck tail was the only other bit added for the RS3100, the GAA cyl heads were part of the 'kits' that had to be made 100-off.

Hi Greg, yes of course you are right about the class limit. I am always thinking BMW and it didn`t really apply to them as they were already over 3 litre.
It is interesting that BMW, amd maybe Ford, had already built and Homologated the 24 valve engine in `73. But decided not to use it. When they did it was not much of an improvement over the 12 valve for some time.
Still it was the best period of Touring Cars in my opinion.
Alex

[Clive Brown]

Originally Posted by Al Weyman

Yes the 2nd gen Camaro was produced and quite a few as well with a 396ci big block engine in fact I believe it was a 402 but released as 396 for insurance purposes and also understated bhp. But it was an all iron engine and although powerful was a real heavyweight.

The second generation Camaro was also homologated into Group 1 with the all-iron elephant block 454, and ran as such in the RAC BSCC.

[Al Weyman]

Really Clive, erm 454 thats some serious muscle.

[Clive Brown]

The downside was that it was also seriously heavy. IIRC, this led some competitors to use the big block at the power circuits like Silverstone and Thruxton, and the 350 at circuits such as Brands, where handling was at more of a premium.

[Peter Mallett]

And I recall they were seriously good value going through Allard at Thruxton. But surely these were homologated cars with nothing particularly "suspect" about that homologation. I know I stopped the thread at Group 2 but I was hoping for stories similar to the lack of sufficient cars in one location, such as the alleged Gothenberg taxi story.

[chunterer]

Ah yes...

Was this the story where 500 240 Turbo's were supposed to be supplied for homologation counting but there was only 150 present, and even those may just have been rolling shells?