NASCAR comes to Le Mans
June 1976: The United States of America is about to celebrate its bicentennial. And what better way to mark such an auspicious event than conquering a certain French motor racing circuit with some all-American iron?
Three years before, the oil crisis affected the pockets of Joe Public and racing teams alike. Budgets were slashed, ideas sidelined but racing continued if perhaps not as freely as before. The Automobile Club de L’Ouest (ACO), fastidious organisers of the 24 Hours of Le Mans were struggling to fill the fifty-five-place grid for the ‘76 event. They turned to Big Bill France, owner of Daytona International Speedway, home to the Stateside version of the twice round the clock endurance[1]. In a spirit of International Exchange, the ACO would allow NASCAR entries from across the pond under the ‘Grand International’ class.
The Grand National series cars could maintain their hallmarks; namely, a stock body with tubular frame and protective rollcage, body panels in steel, stock suspension components and of course a dirty great big block V8 up front. The only provisos being functional head and taillights, wipers, tow hooks and side view mirrors on both sides. Those low down and darty prototypes might just attempt an overtake on either side. Bill France chose two NASCAR teams – a Winston Cup Ford Torino under the established Junie Dunlavey team alongside a more prosaic entry from one Hershel McGriff. Together, they earned the French nickname, Les Monstres!
McGriff was a privateer but a veteran racer from the late 1940s. Buying an Oldsmobile 88 for under $2,000 he entered and won the inaugural Carrera Panamerica in 1950 propelling him into NASCAR stardom. However, Hershel ran a lumber mill back home in Oregon. Together with a growing family led McGriff to park his racing ideas for over a decade before the racing bug bit back.
Keeping things familial (father and son), once finished at the mill of a Friday evening, Doug would head out to compete in the regional Winston West Cup, the weekend mechanics being lumber mill workers. Their weapon of choice, a Chevrolet Chevelle sporting Olympia Beer sponsorship. The set-up proved successful with victorious campaigns reaping rewards. The Chevelle was replaced by a 1972 Dodge Charger that had been built and prepared by Ray Nichels, linked to future NASCAR royalty Richard Petty.
In the McGriff hands, the Charger won the Oregon State Championship from ‘73-75 whereupon they sold the car, only to hastily retrieve it when the invitation to head to Le Mans came from France. In those far off, innocent days, it was widely considered the Charger’s shape was better aerodynamically for high-speed laps over any other current NASCAR fare.
Fettling the car as per the ACO’s strictures, spares, including engines were crated up[2] in preparation for the trip across the Atlantic. Petty and Nichels had discovered a power advantage by fitting Wedge heads onto (what became known as choaked) Hemi heads. Two spare mills came over – one stock Hemi head, one Wedge topped.
As a means of instilling some interest-class rivalry, teams McGriff and Donlavey were backed up by four IMSA representatives comprising a Chevrolet Monza and Corvette with a brace of 911s – one RS, one RSR. Also consider the Le Mans big guns consisted of a Porsche 936 driven by a victorious Jacky Ickx with Patrick Tambay in an Alpine (DNF). Henri Pescarolo and John-Pierre Beltoise in the Inaltera (18th) with Ford also providing power to both Mirage, piloted by Derek Bell (5th) and a Lola with fellow Englishman Alain de Cadenet, who finished a highly creditable third. Other notable entrants being a Lancia Stratos (20th), five BMW 3.0 CSL’s, the usual flotilla of Porsche 911s and a lone de Tomaso Pantera – sadly, a non-starter – engine fault.
With engine maladies we remain. A standard NASCAR engine was tuned to run on octane over 100. McGriff’s knew the French race ran on standard pump fuel thus the engines (both heads) had visited Seattle-based Precision Engines for a 93-octane tune. The Wedge Hemi had an 11:1 compression ratio – good for 630bhp and 215mph along the Mulsanne straight. The standard Hemi ran at 13:1 with broadly similar outputs.
The problem lay within a measuring anomaly. European and American octane ratings differ; the European style 93 significantly lower than the equivalent Stateside 82, which led to almost instantaneous trouble. During qualifying, such lean running led to burnt pistons after only a single lap – the time of 4:30 meaning a lowly grid start[3]. Short on time in as much engineering tooling, the only workable solutions were to retard the timing, enrich the mixture and even fit a second head gasket to try and reduce compression.
The Americans, though competitive were in holiday mood. Whilst miffed at the problems, the McGriff team thought nothing of filling the Charger with teammates and heading off into town, stretching the car’s legs along the Mulsanne. Fabled tales of a trip to the Tertre Rouge corner café linger long in local minds.
A hot and dry race day ensued. Knowing the inevitable outcome, the McGriff Charger was flat out down the Mulsanne when the engine cried enough on just its fourth lap. Out but not down, the McGriff entourage headed home still crowd favourites. The engines returned to Precision, the McGriff’s continued racing at home until 1980 when the Charger became part of the lumber mill’s liquidation, the car’s purchaser unknown.
The story does not end there. Around twenty years ago, Christophe Schwartz, a French journalist and muscle car fan, saw a picture of the ‘76 run Charger racing in his home country. Under a favourable star, he was introduced to a relative of the lumber mill. Kevin Pierson, son of Dick Pierson and the chap entrusted with running the mill in Oregon on the McGriff sojourn. The Pierson’s introduced Schwartz to Chuck Shafer, a former stock car driver and owner of a ‘72 Charger with Hemi set up. Accurately restored (but not identical) in Olympia Beer livery, Schwartz became the Charger’s next custodian[4] although the car was still set up for oval opposed to twisting racetrack nature.
Schwartz managed to bring the car home unchanged for the 2006 Classic Le Mans, mentioning how the steering wheel was held “hard right” on the famous straight at 180mph. Yet more luck fell his way when one of the original Wedge Hemi heads appeared on Craigslist in 2010. Upon detailed inspection it was confirmed to be one of the original Precision Engine heads sent to France in 1976, though not necessarily used.
Now combined as such and with a definite track focussed mechanical set up, this 3,800-pound car takes some stopping; brakes being vintage Hurst/ Airheart discs. Schwartz takes in the classic European racing scene where “the faster you go, the better it feels, above 80 and onto 180, it’s a fantastic stock car.”
Data Sources: Roadkill magazine – Fall 2017, Motortrend – 18/09/20
[1] what would later become known as the Rolex 24
[2] Rumours of crates marked up as “Lubricant” containing Olympia Beer have not yet been sunk
[3] The Torino faring little better, 55th – dead last but they did start. A gearbox failure in the 11th hour of the race put paid to their attempt. Consider a lap on Le Mans demanded around twenty-two shifts per lap. Frequently, NASCAR races barely shifted the stick twenty times their whole race.
[3] Shafer was reluctant to sell but sadly died in a farming accident in 2005. His wife, Cindy wanted to make good on a verbal promise.
Driven To Write 
That would be l’Automobile Club de (not ‘a’ and, even then, to be precise, ‘à’) l’Ouest.
Good morning Brieuc and thank you for the correction, duly made.
Great story! A shame about the rubbish fuel they had to use at Le Mans though. IIRC this has been a recurring theme for US based teams visiting France to race the 24hrs. Even Group 44 experienced this issue. It sure would have been be interesting to see how the NASCAR Charger would have fared if they hadn’t had the terrible detonation issues. My guess is that their brakes would have needed very, very careful management throughout the race (although Chrysler did have constant-loss water-cooled brakes available for racers from the late ’60s- possibly these would have helped). Had the engines not been detonated and the brakes held out surely they’d have finished well up the list. A double shame that the NASCAR men didn’t return and build on the experiences that they’d gained at wonderful Le Mans.
There are two engines mentioned in the story. One is the famed 2nd gen 426 Hemi. The other a 426 wedge*. The 2G Hemi were offered for sale to the public in order to homologate them for NASCAR. The size was 426cid which is a little under 7-litres. This was the upper limit that was allowed in NASCAR at the time. For endurance racing on the high ovals a 426 Hemi was run at anything from 600 to 800 bhp. For sprints and drags they could be set up to surpass 1,000 bhp. They were and are strong. While the Hemi was meant to be raced in NASCAR at 426cid, there are some rumours of even larger versions being run (well and truly against NASCAR rules…….if you got caught). The largest I’ve heard of is ~9-litres. This would be risky, as a wining car running that engine would be in grave danger of being detected and disqualified. But it was run and it won a championship. The way they got away with it is really, really cunning.
After a NASCAR race the victorious car was checked by the scrutineers. Of course they were aware that an oversize engine was a good way to get extra performance on the track (either by extra power, or by reducing rpm to a more modest level for better economy and potentially improved reliability). They could check for oversize engines easily enough. The usual means was to pull a sparkplug and measure stroke and bore of a cylinder (there are several tools or procedures you can use to do this without needing to remove a cylinder head). So, if you did run that bigger than 7-litre engine, you might do well in a race but the post race scrutineering would detect your larger than legal naughtiness. Oh no!
A well-known often victorious team (with a very famous driver) happened to have a most excellent and clever engine builder. He was aware that big 90-degree vee V-8 engines with two-plane or cruciform crankshafts were giving certain main bearings a harder time than the others (usually #4 gets it the worst**). He was also concerned at the issues of torsion, shear and bending with the crankshaft. All of this caused out of balance issues and destructive harmonics if allowed to persist uncontrolled. He reasoned that in a single carb V-8 engine not all cylinders operated identically. Some received richer mixture than others, hence ran cooler. Further, the cylinders at the end of each cylinder bank experienced different cooling regimes than those in the centre of each cylinder bank. So, he understood that none of the cylinders had the same temperatures. Some deal went for gas flows, mixture quality, flame speed etc. None of them experienced exactly the same combustion characteristics or force transmission as the others. Worse was that as the crankshaft distorted under the punishment it was getting while racing the correct timing of the spark plug firing event was different from what would normally be set. Some cylinders were fired too early and some late. A major deal for the Hemi was its valve timing was similarly affected since its valve gear was notoriously heavy… Problems, problems, problems!
All this meant that the engine would not run at its best since it would need to be tuned conservatively enough so that the cylinder/s most susceptible to detonation wouldn’t. That meant all the others ran below their best potential, some by quite a lot. Now racing is racing and no good engine builder wants to leave anything on the table for a competitor to get to first.
What could be done? Our clever engine builder tried what others were also doing. He could compensate for some of the gas flow variation with careful manifold and port shaping, but this only got so far. He started thinking things through even further and ended up treating the engine as not a single V-8 entity but as eight separate cylinders, each of which needed to have its valve events and spark timing optimised for its own particular conditions. He ended up inventing the scatter cam (or, perhaps re-inventing it since in the UK scatter-cams were also being developed by people racing A-series engines to compensate for their siamesed port layouts). He started experimenting with the piston dome shapes to optimise those to each cylinder. In the end each cylinder was different. Power increased substantially.
Now recall this engine builder (who is still alive and has a reputation which it isn’t my purpose to damage) was exceptionally bright, really clever. He had an advantage over others running the Hemi, but the word about scatter cams leaked out, as did knowledge of his bespoke distributors (he needed to use outside vendors to build these components- people do talk, especially when they want to tell you about someone else’s secrets). He needed something else to stay ahead. He found it. It was so weirdly different that no-one else understood what had been done for quite some time (more than a season). First he sought more rpm, but this could only go so far as the Hemi crankshaft was really starting to get trouble (some competitors destroked their 426 Hemis down to as little as 400cid so they could live with higher rpm- one step back, but OK as it got you one and a half steps forward!). Not enough. He went one better. The unfair advantage our man concocted went like this.
If all eight cylinders were already different from each other in terms of port shape and volume, manifold geometry, spark timing, piston dome shape, valve timing and lift, temperature and cooling what was left that could be altered for better result? Here he changed direction. Now he started thinking of the engine as an entirety, a single entity once again. The Hemi would provide more power if you gave it more rpm. Its cylinder heads could certainly support the extra flow easily. Trouble was that if you gave it more rpm the crank started getting into trouble, as did some of the mains. So again, what else could be altered? The answer he came up with was bore, stroke, rod length and compression height. What if each cylinder had those dimensions amended to optimise not just itself but the entire engine? That is, could the crankshaft be given a better situation if each cylinder had its basic dimensions amended? He considered what if each cylinder was given dimensions that were different from others? That is, they did not all have to be the same. They only had to have what worked best. He began to experiment with this and soon found he was onto something. The engines really woke up and his Hemis were stronger than anyone else’s (even the factory did not know what he was up to).
But then people started to compensate their performance disadvantage by taking the chance and racing larger than 7-litres engines. As quick as his advantage had been developed, with all that secret development work, it was being overwhelmed by engines with more cubic capacity. Other people would have complained and litigated and so on. But remember, this is a very clever engine builder we are discussing. He noticed something. He observed that the scrutineers pulled only one sparkplug to make their measurements and having determined the volume of one cylinder they multiplied that by 8 to come up with the total capacity of the entire engine. That cylinder was always #1 on a Hemi, simply because it was easiest to get to. Even though his engines had cylinders of differing swept volumes, whenever they were checked by this method they came up legal at less than 7-litres. They scrutineers calculated 424 cid even though in reality those engines were actually at 427 cid and change.
It was not so long after that when his ultimate Elephant engines were created. The variation in swept volume between cylinders was substantial. This had the advantage of cleaning up the damage occurring at #4 main (reduced peak force) and reduced the magnitude of the distortions the crankshaft experienced under racing conditions. Best news was that total swept volume was up by 2-litres. That was an advantage. There was one other notable feature. When the volume of #1 cylinder was measured by the remove-the-sparkplug method it come out at exactly one eighth of 426 cid and so the engine was calculated to be a legal 426 cid. All OK by NASCAR. Who’d have guessed that so much extra performance could be gained by an increase of 2 cid?
There are a few tells that do give the game away though. It has a slightly different sound to a regular 426. You definitely can tell something is up when you listen. It also has a really terrible idle quality, but then again, Hemis idle like a coffee can full of rocks anyway (and it can feel like you are in there with the rocks). I’d certainly not call it a smooth engine, not until you really lean on it, then it gets better.
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*I’d like to discuss this engine another time. There are a few questions about it I’d like to find more about.
**The problem with chopping out some of the mains in a 90-degree V-8 with a cruciform crankshaft is also experienced in Pro Stock. One solution to this was to reduce the vee angle to 80-degrees. This helped the mains and also allowed a nice direct shot from the intake runners direct to the back of the intake valves. Such an engine was being developed by the great Warren Johnson. It got banned and so that project was unfortunately cancelled.
Mercedes Benz AMG division were also working on an 80-degree V-8 of a little over 6-litres (I think it was either 6.2 or 6.3). It was to be turbo-charged. Not for Pro-Stock or even V-8Supercars but intended for a road going GT car. Unfortunately cancelled. When I enquired about this one I was informed they sought improved packaging and to reduce the main journal diameter. How interesting…
Fascinating info about those engine tricks, J T. An article in itself, really.
The USA had been more succesful at Le Mans many years before, in 1950. That year Briggs Cunningham fielded two Cadillacs- one virtually stock Coupe de Ville and the other a special-bodied aerodynamic version quickly nicknamed “Le Monstre” by the public. Very impressively, the cars finished 10th and 11th overall, with the stock Coupe de Ville finishing ahead of Le Monstre. Looking at a 1950 Cadillac Coupe de Ville it’s amazing that it performed so well against many sportscars and speaks volumes about Cadillac’s ability to create mighty road cars in those days.
… and here they are:
History is about to repeat itself in 2023, with an entry of a “next gen” Chevy Camaro in the Garage 56 scheme:
https://www.motorsportmagazine.com/articles/sports-cars/le-mans/nascar-chassis-to-race-at-2023-le-mans-24-hours-via-garage-56
(image BlackBook Motorsport Forum/Handout via REUTERS)
It’s almost hard to believe that NASCAR “professionals” were too naive to realize that not everybody’s pump octane nomenclature was the same average of RON and MON ratings that we use in the USA (even though every USA gas pump is marked “(R+M)/2”). I just pulled my old Internal Combustion Engine Fundamentals textbook off the shelf to confirm my recollection that the differences between RON (Research Octane Number), MON (Motor Octane Number), and AKI (AntiKnock Index–the average used by USA retailers) are clearly spelled out in undergraduate university coursework. But then it occurred to me that a NASCAR engine builder of the ’70s might be precisely the sort of blue-collar “professional” who thinks they’re too smart for any kind of pretentious ivory tower “book learning.” How unfortunate for the racing teams who hired them specifically to tune a NASCAR engine for 93 [RON] octane fuel (which would be like 88 [AKI] octane, not 82 as implied above)!
Reminds me of the time I pulled a pre-1960 coin of my pocket and was gently but firmly informed that despite it having been engraved quite clearly with the word “Francs” it was worth only Centimes.
Or the time my government lost a $125 million Mars orbiter because a Lockheed Martin engineering team used English units of measurement while the NASA team had calculated its trajectory in proper metric units.
Now considering how parochial we are, isn’t it miraculous that a lardy 1972 Dodge could have ever been even remotely competitive at Le Mans? Looks like a rocket ship though, doesn’t it?
Re the idea that…..a NASCAR engine builder of the ’70s might be precisely the sort of blue-collar “professional” who thinks they’re too smart for any kind of pretentious ivory tower “book learning.”
That was never the case at all. These guys simply wanted to race AND they wanted to have fun (which was a big motivator- read what they actually said about their experiences). Their culture is not one of considering themselves “too smart for book learning”. For example, Smokey Yunick disclosed how much he owed to what Americans term “college texts” (which the British are more likely to refer to as University textbooks or even as specialist publications or academic papers). Learning, whether by reading books, by word of mouth, discussion and debate, formal or informal education, practical experience and empirical methods, all were means by which they gained their knowledge. All were recognised as valid approaches and all were deployed. The point to note is that these men came from a culture where they enjoyed their racing. There are surprisingly many who do not share the characteristic. For them it’s a job/career/profession- not so much about fun then, therefore more serious and somehow “better”. How sad to be one of those and live like that. Better to have fun.
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There is a well known book by Bill Jenkins (a.k.a. Grumpy Jenkins) called “The Chevrolet Racing Engine.” He was a drag racer and engine builder (and transmission and suspension builder for that matter). This book was published in the 1970s at around the time the Cosworth V-8 was doing so very well in Formula One racing. There is a story which relates to the book. It occurred that some US engine men visited the UK to attend a conference, tour around the scene, meet some locals, attend a few seminars, view the sights, see Buckingham Palace, say hello to the Queen and all that. One of their hosts ran a luncheon event for them. A guide was provided to get them to the venue and drive them around for a bit of sight-seeing. This guide happened happened to be an engineer from Cosworth.
When it was time to say their farewells and return to the US, the guests decided they really ought to present a gift to acknowledge the generosity of their guide. On their final day, one of the group ran over to a certain well-known London specialist book shop (betcha can’t guess) to obtain something good for their new friend to read. It needed to be of a US flavour and technical (obviously). The Jenkins book was just the ticket. They well knew the content. After all they’d bought a number of copies of this very book with them but had given them out to others earlier in their journey so had none left. Luckily there was one copy in the shop and so it was duly purchased. When it was time to present the gift to their new friend he showed little interest at all, explaining that such engines were primitive in comparison to what he was working on and hence held little of interest to him. When in the general course of conversation it was revealed just how much one of Grumpy’s engines was producing and what its specific power was this attitude immediately changed. The book was grabbed off the table and tightly clutched. No way was it going anywhere and needless to say it did not return back to the USA!
Moral of the stories: Be careful of the initial temptation to underestimate.
There may be good reasons why we’ve all heard of Smokey Yunick and not Precision Engines of Seattle. My point was that if these guys had ever bothered to pick up a textbook, they’d know not to take a customer’s money to tune an engine for “93 octane” without getting in writing whether that meant 93 RON, MON, or AKI octane. I was initially wondering if the whole “93-RON-oops” story was actually a fabrication to cover up a more embarrassing error of some sort. But then I realized that these guys may have had less in common with the likes of Smokey Yunick than with the sort of machine shop proprietors I remember from my youth in Ohio in the ‘90s… and suddenly the possibility of never having either picked up a textbook or traveled outside of the USA seemed totally plausible… hence my earlier comment. (But perhaps I should be careful what I say—I live in Seattle, across the street from an apartment block that only rents to retirees—the knuckleheads from Precision Engines could be my neighbors!)
gooddog
…..or an initial mismatch of the ring sections of the Montreal Olympic stadium (a.k.a. the Big Owe)- another unit conversion error.
These big expensive errors are more or less inevitable, deliberate even.
I was once party to a pretty silly unit ‘conversion’ error: A dynamic simulation of a helicopter strapped down inside a bigger aircraft just wouldn’t converge (i.e. it crashed the computer), despite weeks of tweaking by a colleague who was an expert at such things. I eventually asked my colleague to show me the numbers the customer gave him for the mass properties of their helicopter. I started with the inertia about the longitudinal axis to see if it actually made sense for a 20,000 lb helicopter, and quickly realized the only way to get that inertia number and a 20,000 lb mass would be a very long 2” x 4” made of plutonium. To actually get that mass to align with the complete set of inertia properties we’d been given? That required a (American) football with the density of a collapsed star. But if I changed the units on the inertia numbers, suddenly the numbers we’d been given made perfect sense for a large helicopter!
Wow. What fascinating stories. I remember watching Herschel McGriff (from Bridleveil, Oregon) race at the Redwood Acres dirt track oval in Eureka, California. Great memories