In the sixties, if you had arrived on earth from Mars as a raving racing saloon car nut, you would have quickly realised that there were only a few car brands in certain parts of our planet, namely Ford, Mini and Renault, with an occasional appearance from Alfa and Volvo….there were quite obviously no others. Not known to our Martian friend, this was not strictly true….. but… living on a planet ruled by the Homologencia could, I guess, be aligned to living in a benign dictatorship. The homologation police were strategically located, well trained and had a worldwide hold on anyone seeking to pass Go without paying the required allegiance. I just felt that bucking the system, though tricky, was very necessary in order to expose this capture and control of enthusiasts trying to compete with No Name Brand cars……. Here is a two part tale of how we fared.


Old style Minis have been a constant and somewhat annoying pain in the butt for years. While proper cars came and went in an orderly fashion as time went by, these things were never replaced….. they were always… just…. there. BMC (British Motor Corporation – becoming British Leyland during the period) originally not able to afford a replacement due to Minis being sold without making a decent profit,* had to keep the original design going to keep the cash coming in. The cars were quite cute though and when the iconic status kicked in, this saved their bacon and they overstayed their welcome some more….and then some more. Whilst all this was going on, the go-faster folk had a field day and took these dinky toys to motor racing nirvana. That this was achieved at all is testament to the absolute brilliance of the human race.  For starters the engine is a piece of ancient British architecture which rightly should have been locked in a museum a long time ago….But….. against the apparent laws of physics, became very effective race weapons, the archaic ‘A’series BMC engine eventually becoming one of the more prolific production based racing engines of the era.

Mini 1

From the first Mini – Through the derivatives – To Rally success and all types of racing

Soon after the launch of the first Minis, Ford Dagenham management in the UK smelled a rat with respect to the selling price of the little cars. They investigated the issue by buying a car, put an engineering and procurement team together and stripped the vehicle down to the last nut screw and bolt. They completed a costing exercise via their own supplier network and conducted an engineering study to assess assembly and development costs. The result of the exercise proved that BMC were not making anywhere near sufficient profit on the car, particularly in the area of funding new models . The irony was that Ford executives knew more about the real costing of this new contender than the execs at BMC. That did not help us non-believers though, the mini roller coaster was by that time well on its way.

As if that was not enough.….. we also had Ford Anglias by the bucket load. This was different…… and not about the laws of physics being broken….. but about boffins in a shed in the UK plotting the downfall of those men in their Minis. Think about this for a moment….the 997cc Anglia in its heyday was fighting for first position as the slowest one litre car on the planet and, where that would be a red flag to most, it did not stop the boffins in that shed from producing a silk purse from the proverbial sows ear. The engine so developed helped win the British Saloon Car Championship in 1966 (along with huge poetic licence from Ford and their magical homologation pen). That crummy 37 bhp was now at 120 bhp and the tachometer red line locked at 10,000 rpm….. the Cosworth MAE (Modified Anglia Engine) began a racing engine dynasty that was to rock the racing world for the next 20 years. We’ll cover those 20 years in Part Four of Fordomonation coming up in a few weeks.

Anglia 997 – Moms 60’s taxi

Typical 60’s type  Streetfighter

Lionel Rowe Broadspeed Van Stadens

60’s Broadspeed Racer – UK Champ

……But…..This story is not about those Anglias or Minis….it’s about common sense…..

Modifying cars is without doubt an art form and some folk do it so well and with such finesse that one is quite literally left speechless. My first brush with this kind of talent came one evening in 1969 in my home town of Port Elizabeth and helped me to understand what was needed in this most competitive environment. Shortly thereafter, a second contact with something rather special got my attention and further motivated me to chase down a project simply to set the record straight.

At the risk of repeating comments in previous posts and for those reading for the first time, let me sketch the background. In the 60’s, Port Elizabeth was South Africa’s very own Detroit. Both Ford and GM based their assembly and manufacturing plants in the city and everyone seemed to be connected to one or other of these giants through family, friends or business. That year was the second of my training at the General. As mentioned before, I was sorely disappointed and somewhat frustrated. Firstly, the ‘quick part’ cupboard was bare, this was not the USA where GM were already up to their armpits in Muscle Cars, Corvettes and Z28’s. The culture in this place was clearly focused on manufacturing and selling cars… GMSA was great at that, this was a very good manufacturing and marketing company with a well organised and effective, if conservative, dealer network….but…the product was very much a consequence of the process…. Incredibly, car enthusiasts were thin on the ground… I kid you not.

Ford, just down the road, however, were heavily product focused and bursting at the seams with a built-in go-faster car ethos. The larger Ford family contained many nauseatingly committed enthusiasts, most of whom were very, very good at what they were doing. Modified Fords grew out of the pavement….especially Anglias. Being an enthusiast myself, the choice was simple, join the Ford gang or get some stuff done with the Generals product…. my non-conformist streak made the latter a simple preference and I set about trying to make some sense out of this rather restricted tuning environment.

That scene was daunting enough, but Ford was not the only problem, there were those damn Minis to be dealt with. The local Speed-shop, PowerKing, run by the Wood brothers was a BMC stronghold and modified Minis were almost as plentiful. Add to that the Renault contingent in good numbers and my Opel Kadett was outnumbered a hundred to one…. But…. The Opel had been chosen as my weapon of choice and it was a case of sink or swim. As a street car, the Kadett had been modified and was, in the Martian viewed environment, also annoyingly quick but it was a first stab for me as a greenhorn enthusiast. Despite the threat of having the homologation police knock at my door in the middle of the night, I had recently decided to turn my sedan road car into a racer and had acquired an old Kadett ‘wagon (Car A Van) as a daily runner. One evening, early in this caper, the road car engine was stripped and on a bench in the garage threatened with being upgraded into a racer….plenty of ideas but no firm direction yet.

993 engine bits
Chevy style valve train

On the Bench – 993 Opel – Steel internals  and SB Chevy style lightweight hollow pushrods and pressed Rockers.

As fate would have it, a friend popped round and was on his way to visit Kingsley Wood and twisted my arm to come along. This suggestion was out of left field….Kingsley was technically going to be the enemy….he was  one of the Wood bros, owner of that local speed-shop and running the quickest 1000cc race car in the Eastern Cape and Border, a 998 Mini. The thing was quick and well prepared, bristling with factory bits. Evidently some arrangement had been made for a few guys to visit that evening….. Did I want to come along?   Sure I did.

This turned out to be a lesson of note. Kingsley, from memory a toolmaker by trade, was rebuilding the 998 race motor as we arrived. On the bench in the neat workshop was the upturned cylinder head with the affable Kingsley doing the assembly. I was completely gobsmacked. Having seen many modified cylinder heads, from amateur efforts to race and road stuff in the local speedshops and countless pics in all manner of mags and tuning publications of the day…. this was special. Add to that my own attempts on the old girl’s Opel, my road car and a good few freebies done for friends running GM, I could be forgiven for thinking that I had a handle on things. I did not. The ‘head on that workbench was a work of art. Combustion chambers were beautifully contoured and identically finished. Valve throats and valves fabulously detailed and ports similarly well profiled. For those familiar with modern C&C milled alloy masterpieces, give a thought to the cast iron monstrosities that were the pieces worked on in those days. To arrive at the outcome seen on that workbench needed special talent, there would be much soul searching in later days. Going back to that art form I spoke of earlier, I realised that I would have to raise my game considerably… to be quite candid….a swift kick in the butt did wonders…

As sobering as this lesson turned out to be, the direction and inspiration I was looking for was motivated by what happened next. That cylinder head bothered me. As beautifully finished as it was, the five-port arrangement was, in my opinion, fundamentally ‘wrong’. Here I was, in the realm of the local championship winning car and can remember the thought …‘this is not right’…. Bear in mind that by 1969 we had (kind of) accepted that Minis were hot racers and without any real thought figured that something special in these machines brought that about…. Rubbish…. Minis were quick because the right parts were available to make them quick and if you added the type of preparation Kingsley was capable of, you would have a winner.

Strolling over to the immaculate block subassembly mounted on the close ratio Mini gearbox and looking at the general appearance of the ancient side covers, tiny bores and mineshaft long stroke, a most irreverent thought crossed my mind. ….. “Robert Louis Stephenson has had something to do with this”…. Compared to that little Opel engine stripped on the bench at home, it was just plain “ancient”….. No bloody way was this thing going to produce more power than the Opel….. I arrived back at my tiny garage, collected a cup of coffee and sat oggling those engine parts…. every single component was more raceable than that BMC ‘A’…Forged steel crank and rods, beautifully waisted con rod bolts, short lightweight hollow pushrods, a compact engine block, ideal bore stroke ratio, and a downport cylinder head with huge potential.

998 Mini head  race prepped

993 Kadett head

993 Kadett head  race prepped

What we were supposed to believe is that the 998 Mini Cooper head would ultimately flow more air than the Kadett Cylinder head (given the same R&D) …..I don’t think so….

998 block

The 998 Mini engine block

Chevy Inspired 993 Little Block by Opel

Chevy inspired 993cc GM Little Block by Opel.

MAE Cosworth Engine Block 2

Cosworth 997 MAE Engine Block (Early Kent)

The irreverent thoughts continued. Just how had such an archaic piece of British junk got to being so effective? If that chunk of iron could do it, the Opel had to be better…. or the laws of physics and the application of common sense were screwed up. I set about doing the job but still with no clear idea of what the silver bullet would be.

Then the Ford experience.

The product of those boffins in that shed in the UK, turned out to be the Cosworth/Holbay tuned Anglia engine fitted to the 1966 UK saloon Championship winning Broadspeed Anglia. The car was now in PE. This car was owned by Ford SA, run by the late Gordon Briggs in the SA National saloon car championship and was the ‘other’ 1000cc race engine I had managed get a good look at. I was and still am, extremely critical of the fact that as fitted to the Anglia, this engine was nothing more than a paperwork homologation special derived from the F2 Cosworth mill, but nevertheless, special it was. Unlike the BMC 998, this was a proper race engine, the history fabulous and had kick-started what we now know as Cosworth today. Although, like the Mini at 1000cc, nothing…. absolutely nothing…. was remotely similar.

As absurdly disproportionate as the long stroke was on the Mini engine, the Ford was the exact opposite….an equally disproportionate short stroke and massive 81mm bore. Valves were as big as most production 2 litre engines, billet steel crank, slipper skirt two ring pistons, enormously rigid steel caps and the piece de resistance….that downport  F2 cylinder head with matching IDF’s. Respect was duly given…..120bhp at 9000rpm from a 997cc production-based pushrod engine in the 60’s….and that 10,000rpm redline…. would tend to require that.

Opel Siamesed Downport

Opel Siamesed Downport

MAE Cosworh-Holbay Downport

Cosworth/Holbay Downport

Super Short Stroke MAE Billet Crank

Super-short stroke – Billet Crank – Cosworth MAE

993 Kadett Block - crank 2

Stock Opel 993 Steel Crank set up  

The Penny dropped. It was absolutely not about whether it could be done with the Opel, it was merely how long it would take.

Put simply, if the two engines morphed and resulted in a 50/50 DNA split, the result would be the 993 Kadett mill. Firstly, it would produce a proper Bore/Stroke ratio, the downport cylinder head with siamesed inlet ports mimicked features of both engines, a solid, modern block and the steel bottom end took care of the muscle required to keep it together….all that was required was to find out how to make it breath. The earlier question on how the mini engine managed to be effective was answered simply…. it had to do with Shakespeare and the infinite monkey theorem.

“The infinite monkey theorem states that a monkey hitting keys at random on a typewriter for an infinite amount of time will surely type a given text, such as the complete works of William Shakespeare, or at least a good part thereof.”

The fact is that in the 60’s, 100’s (if not 1000’s) of boffins worked on the “A” series mini engine and amply illustrated by Kingsley, were most definitely not monkeys. There were a lot of them bashing at the keys. There had to be a result…. and there was…. The top list of names and magic numbers is endless……the engineers at Longbridge for a start, Cooper, Downton, Armstrong, ‘S’, 731,648/9,850, 997, 998, 970, 1071, 1275,1293, 1440, then later, Longman, Vizard and an infinite supply of these learnings passed to enthusiasts via magazines and books published by the boffins. Add to those the availability of tried and tested special parts…. and there had to be that result…. simple. These were special folk who could have been working on a cabbage and the result would have been horsepower. The iconic status of the car, huge support from the Longbridge connection and the fact that by 1969 production had already run ten years, did not hurt at all by keeping the homologation docs (and continued development) intact. Aside from the natural inbred competitive spirit driving those involved, modding Minis made straightforward business and racing sense….this was not going to be easy.

The Ford Anglia case was less frenetic and far more logical from an engineering perspective but very much the same thing. Some of the best minds in the business from the Ford’s go-faster juggernaut were involved.

Translate the background of these two engines into what the Opel was about. GM was not only disinterested but openly anti racing. The homologation docs were a reproduction of the standard Opel sales brochure and as a race car, was effectively dead in the water just because of that. On the face of it, it absolutely did not matter whether the machine had potential, the homologation police were ready……….but….Port Elizabeth was a special place. Our smart regional racing authorities had just given the middle finger to the new national Group 2 ‘Asthmatic Olympics’ regulations** (1970 for ‘71) and wonder of wonders…. our racing was based on the late 60’s group 5 regs with the addition of…… ‘what you can do… I can do’.  The need for the one-sided homologation nonsense was thrown out of the window. The Opel was instantly legal and I scraped together the money needed to buy that 46IDA Weber downdraught.

**The early 70’s saloon car racing regs in SA specified that both the standard inlet manifold casting and the number of carburettor choke tubes fitted on a standard road car were to be the basis for racing.  Stupid with a capital F.  This forced a) the exit stage right of many cars not fitted in standard form with multiple carburetion or “big” manifolds  and b)  forced those manufacturers so affected to build specially homologated cars in very limited numbers in order to compete. The positives were that cars like the Datsun Z’s, Capri and Cortina Peranas as well as the Firenza Can Am were built ….but at the same time killed the possibility of cars like the Chev 38/4100 and many others to be competitive, the Kadett being another. The Irony of this situation played out later in the 70’s when free carburetion was allowed and that same Chev 4100 became the fastest SA production racer in 1978/79. There was another positive…… and that is something we are going to cover in future tales in this series…how some brilliant local engine tuners overcame this diabolical regulation.

I then started the process of getting the job done. Firstly I was most definitely not a Longman or a Vizard.  I did not have information from 1000 folk to rely on and initially it felt a lot like heading for a gunfight with a plastic spoon.  I did however have the flexibility to choose direction and the ability to guess. So how in hell was I going to do this? Firstly the racing bit for me was a means to an end, call it the test or outcome of work done. Strange as it may seem, to me it was not about winning races…I am not a natural circuit racer, it was simply ‘get this engine to produce more power than that Robert Louis Stephenson thing’…. and so I did race……but should have realised earlier that teaming up with a decent driver to get the job done properly would have been the smart idea. I did however take ¼ mile drags seriously. Firstly I was good at it… and besides, it was always a pretty decent measure of outright horsepower.

That Annoying 993cc Kadett

That annoying 993cc Kadett

Not so Good Pic - 46IDA and manifold

Not so good Pic of the 46 IDA & Manifold

The Opel OHV is a natural revver, 8000rpm for a street car was a piece of cake.  For me, having chosen the basic architecture in using a big downdraught 46 IDA Weber, the first task as I saw it, was to find a cam profile that had a semblance of punch… and to work around that. The road car had responded reasonably well to BMC style timing (731/649) with good rpm and reasonable power but no real “snap”. The Inlet manifold to fit a 46IDA was acquired from Blydenstein (Viva) and modified to fit the German engine. Cylinder head mods were based on a very simple principle of opening the ports, radius carefully and not change port shapes too much, re-profile the valves, then doing a careful 3 – 4 angle valve job. Compression was a low 10.8:1, best I could do on flat top pistons ……Done….horsepower was instantaneous. –.  Not good enough to clobber the mini but a better step forward than expected.

More head scratching. The original thinking was that because of the inlet port configuration it would be safest to follow that BMC valve timing route… made sense but not horsepower… here is the kicker. Despite the siamesed inlet ports, the Opel engine was very different in power delivery from the BMC ‘A’, it never really fell off the power curve at the top-end and would seemingly continue to run to ridiculous rpm.  Running to 9000 was no big deal, but still no “snap”. Many of my early attempts felt rubbery. OK then, so I tried some Ford based profiles…. Basil van Rooyen came to the rescue and a TR68 was installed plenty Snap.*** The engine hauled from 5500 and ran to 8500 pulling well all the way. Next step bigger valves and add some compression.

At around this time and in a completely unrelated project at work in GM engineering, I had my first ‘lightbulb’ moment in understanding valve timing dynamics.  The relationship between engine compression ratio and valve timing struck home when the ’69 spec Z28 302 engines arrived for the Can Am. These were engines running 11:1 compression as a street spec and the question was whether operating on the available 93 octane (RON) at sea level would result in serious detonation (knock). Bear in mind that at 9:1 on some stock Chevy V8’s, combustion  knock was a regular visitor…. My expectation was that it would….. It did not…. That did not make sense….until I took a good look at the valve timing of the Duntov 30/30 solid lifter cam. I still did not fully understand the link… but became sufficiently involved to eventually catch on to the critical Inlet valve closing point being the direct connection to establishing dynamic compression ratio…..much more of that in later tales.

Please bear in mind, all this is taking place on a trainee salary of what was then about R30.00 a week, so saving for each “mod” took time. A local dealer, Fleet motors, (I avoided Hunts due to the Ranger debacle) had taken an interest and paid entry fees and fuel for any racing or sprints. The Kadett was now about 0.7 sec off the mini in a ¼ mile and as a track car still way off the pace….. most of that still due to the driver….

The move to bigger valves was a leap of faith. Two problems. Firstly the only valves available (affordable) were Vauxhall Viva and after suitable re-shaping they could do the job….but… this was the British version of the same engine (softer in all critical areas) and the damn things had butt welded stems. Visions of this lot coming apart at 8 Grand were a real nightmare…No real choice, so had to use them. The second problem was that with no special part availability to raise compression, the stock piston crowns had to be milled and the block decked. I now had the dual problem of having to increase valve pocket depth for the larger valves as well as dealing with thinner piston crowns. Luck sometimes just smiles on you and after close inspection and cutting up a few old pistons, realised that the pin reinforcing struts on the underside of the crowns were smack in line with the proposed larger valve pockets. What would have been disaster, just resulted in enough meat to do the job..  10.8 moved to 11.6, not good enough but getting there.

Sectioned Head
Downport 993 Cyl Head

OHV OPEL Cylinder head –   Inlet and Exh port arrangement and Chevy V8 style wedge chambers

Neat Chevy Style wedge Chambers

By this time I had made progress at the General and had been running the service station rolling road…an awful ‘Sun’ device. Yours truly was the only person who showed real interest in the machine and figured I had got the job because somehow I managed not only to make it work but could get repeatable results. I also had the authority to run the Kadett on the Dyno after hours… “please remember GM is not in racing so don’t spread this around”….yes really!    I must say that without the availability of this machine I would have been lost. The critical need to know how mixtures, timing and many other variables like choke tube sizes, tract lengths and valve timing affected the power output was essential. It was a massive learning exercise and one that set me up to understand the basics in modified engine behaviour…..most beneficial in later years.

The engine in this new spec was now producing a solid 72 BHP at the wheels (a conservative 90+Bhp at the flywheel) and the annual hillclimb was two days away

It was now about 18 months after the night at Kingsleys and the ‘climb’ for us 1000cc folk was pretty much a full throttle blast, the corners not too much of a challenge. The Kadett simply out-powered the Mini, the gap was nearly two seconds at the end of it and the first time the Opel had won the 1000 class. Job done. But this was one of those small victories that one internalises at a tech level. The mini was about 80Kg lighter, smaller, running close gears, a decent final drive with an L/s and racing tyres. The Kadett running radials, tall as hell 3.89 final drive, no L/S and standard gearbox ratios …I remember holding third to over 9000Rpm to cross the line.


Annual hillclimb. This first left hander was followed by an equivalent right hander just to the right of this pic. Big cars like this Fairmont GTHO would have some difficulty…. but for us 1000cc guys it was full bore all the way. The start line was some 200 metres further down the road.

I could say at this point that victory was sweet, it was… but not as sweet as it should have been. On the final run up the hill the Mini ‘lunched’ its engine in a big way about 50m from the line and, as I saw some days later, had fractured the centre main in the block and consequently broken the crank.  This type of failure on a mini causes horrendous damage to the mechanicals due to the gearbox location and for me to see that carnage happening to a fellow competitor took the edge off the win. (so bad was the failure, that standing at the finish line I actually had to duck behind a car to dodge bits of metal bouncing down the road). To be fair that engine had seen many years of hard work. I mention this failure only because Kingsley then rebuilt the mini using the 970 ‘S’ architecture – the 1000cc short stroke version of the ‘S’ engine, homologated by BMC as their primary weapon of choice in the 60’s and as a race motor, pretty near unbreakable.

Fast forward to 1973….

The opening of the main straight at the new Scribante race circuit (track still under construction) and all three 1000cc cars are there. In the intervening period I had done more work on the engine and power was now approaching a realistic 100bhp/litre but the real change was in the overall gearing. To do this I found a set of 4.125:1 gears in the redundant stock of our parts department at GM. This was an incredible find simply because these gears were not only unique long pinion parts but an option for station wagon versions of the same car and had not ever sold in the time since the cars were first built in 1963. The budget had also stretched to allow racing tyres and a choice of either going for 13” wheels and slicks (ideal if gearing was OK) or the original Mini spec 12” CR 84 low profile treaded Dunlops. No contest…..the need to get the gearing right won (this was about the engine…right?) and the Dunlops were called to do duty. For those tech guys out there, the gearing in top with those two changes brought the gearing down from 16.3mph per 1000 rpm to 14.3mph…. for the first time since building the car, this was competitive stuff ….Game On. I have absolutely no doubt that this was the only A body Opel Kadett in the world running at this spec.

The Mini was running the short stroke 970 S at 999cc now owned by Barry Kapelus…… and the Broadspeed Anglia owned by regional champion Lionel Rowe.

For many, this was just another day but for me it was to be a little more than that as I was also running the engineering Can Am test car and had to scoot back to the start line on a Monkey bike after each Kadett run.  The racing was based on elimination runs starting in classes. The first, a scrap between the Kadett and Mini. The pics below showing the race about 100m from the start line.  A 15.74 played a 16.2 the Kadett moving to the next round and two runs against the Broadspeed. On the first run against the Anglia I snapped a rear upper shock stud on the Kadett and lost time off the line…. 15.53 played a 16.05. With that fixed and the notorious PE wind having come up as a headwind, the last run:   Anglia 16.13, Kadett 16.14. Lionel and I were team mates by that time and I pulled his leg telling him he only won that thrash because the Anglia had frog eyes!!**

To put all that into some perspective these are 1000cc cars running to terminal speeds just over 90mph in a ¼ mile.

Kadett vs Mini 1973

993cc Kadett :  15.75sec    Vs    999cc Cooper S: 16.2sec  

All us racing folk have little stories we keep to ourselves simply because telling them could make it sound like an excuse factory. Truth is that on the day, the Kadett engine had not had much TLC for some time and the valve springs had gotten a little tired. Valve thrash started at 8800rpm and that happened to be about 80 metres from the line in third gear….forcing a gear change to 4th. ….at that point I had a nose on the Anglia and lost it before the line.! That’s my story and I’m sticking to it…..0.01 of a sec @ 90 mph is around 15 inches!

Kadett vs Broadspeed

993cc Kadett:  16.14sec   vs 997cc   Broadspeed Anglia: 16.13sec

Kadett vs Broadspeed 2

Broadspeed just out of shot in both runs…but you can see that frog eye…Man with the flag & hat – The late Gordon Briggs (RIP)

So, this tale is most definitely not about how smart I was to make the Kadett competitive….. as I said before, all that had been done was apply what those around me were doing, and using existing tech know-how. There was no trick stuff at all….the engine simply responding spectacularly to being tweaked. Just as an example, crank, ’rods and pistons were original parts.  Despite the limited resources, we were in a position to say that the engine had done what we figured it was capable of and that was at least to be competitive… important to also note that I was just scratching the surface compared to the work done on Minis and Fords.……But we had shown that common sense had prevailed.

As a race car though, I had not yet proved the point…so let’s move on to where the car was called to arms at circuit racing…..this time with a proper driver!

For that part of the story we go to Part Two….. and how this happened:

Round The Outside

Round the outside….

 See you next week for Part Two of the Infinite Grease Monkey Theorem – A Fox In The Henhouse. 

A Footnote on Homologation –  We all know that having a set of rules to control any form of competition is essential, however, homologation requirements in the period were unnecessarily complicated and restrictive. Given that all manufacturers interested in serious racing would do very much the same things to get their steeds fit for competition  ie: Close ratio gearboxes, final drive ratio changes, limited slip differentials, multiple carburetion and bigger valves to mention a few….why police them and require expensive homologation compliance? Then the most irrational rule of all….specifying that vehicles needed to have race weights within a given % of the manufacturers production numbers….. why??…. Simply specify a minimum weight per engine  capacity class. Some would have to run ballast, others run non-structural lightweight panels. On this one, look at history, the smart guys did the panel issue anyway, it just cost a lot of moola to get compliance. The only really tricky bits are the engine mechanicals….. and if you look at the period around 1966 to 1970 the crazy thing is that rules were completely screwed up. There were lists of required homologations as long as your arm  on every conceivable part of the car…but….freedom to cut and weld-up cylinder blocks to you hearts content…absolute…BS.  Worse, turbochargers and superchargers were allowed without weight penalties…just a 1.4 X capacity clause.  This stuff was wonderful for engineers to sink their teeth into….but created completely unrealistic track performance. We’ll talk more about this in future tales.