64 replies to this topic

[Paolo]

As we all know, before the Cooper revolution almost all powerful racecars used to have a front engine.

Yet a rear or mid engine seemed no problem in smaller cars, say 500cc Kiefts etc.

I seem to gather that the opposition to a big rear-mid engine came from fear such cars would develop terminal oversteer due to engine weight at the back.

On the other hand, I never heard of Auto Unions as being especially evil compared to the competition (in the 30's ALL cars were evil to some degree).

A rear-mid engine has obvious advantages in terms of cross section, low speed acceleration, weight and drivetrain efficiency; front engine has few recognizable advantages: mainly a better driver sensitivity due to him being placed quite away from the car's centre of rotation therefore allowing him to experience higher acceleration changes.

The greater moment of inertia provided by a front engine can be an advantage in some circumstances, slowing down the car's reactions, but for the same reason it can turn into a disadvantage.

The commonplace explanation I hear about the switch from front engine to rear-mid engine is that the oversteer problem was cured by suspension improvements; the tendency to oversteer being actually due to the use of unsophisticated geometries (swing axle?).

I am pretty sure a lot of cars had at least a De Dion much before Cooper turned to F1, and possibly some had double wishbones.

If suspension geometry was the real problem

A) why did it affect rear engine cars more than front engine ones ?

B) what did Cooper do that others (say, Bugatti) did not to have a working rear engine F1 ?

[Ray Bell]

I'd say engine weight would be a significant factor in getting the balance right...

Engines were undoubtedly becoming lighter by the time the FPF came into use, and cars were becoming smaller too. There might be a component of the answer to do with tyre technology as well.

[RAP]

I wonder if it is coincidence that Cooper became succesful when Grad Prix race distances were reduced for 1958 and thus fuel loads were less?

[Ray Bell]

An important point...

Not only reduced distances, but also a change in fuel. This meant smaller quantities of fuel were required, so packaging their tanks into the car was easier.

Another benefit of the rear engined layout here was that more tanks could be fitted centrally in the chassis, so the balance of the car didn't change so much during a race.

[Bonde]

Personally, I think WWII delayed the inevitable switch to the mid-engine arrangement. Auto-Unions were very difficult to drive (though tempered somewhat by their torqey, slow revving engines) until they replaced rear swing axles (jacking being the main problem with the relatively narrow tyes then in use) with a DeDion on the D-type. I think had WWII not intervened, Mercedes would eventually have been forced to follow Auto-Union's lead, and then everyone else would have, too.

Had the Cisitalia venture had a proper team behind it things might have looked different sooner also.

I think tyres also were a factor - they simply weren't up to the job in powerful, heavy cars, and with lots of weight on the driven wheels the challenge was to simply make them last the distance. Still, mid-engined cars could be made lighter than front-engined, and as pointed out above the fuel load didn't need to be hung off the back.

I also think simple conservatism and certain degree of anti-German sentiment certainly played in. The early Auto-Unions did give the mid-engine concept a bad reputation, and they were, well, German at a time when it was difficult for some to credit German technology. Then there was the view that the Coopers were just a bunch of 'bloody blacksmiths' - yet they were sweeping the floor with front-engined tool-room built, more powerful cars...

With the benefit of hindsight it is perhaps difficult to understand why it took so long for the engine to find its proper place in racing cars when, with the same hindsight, the advantages of that arrangement are so obviously superior in packaging, structure, mass distribution, vehicle dynamics and aerodynamics. I know Don Panoz thinks otherwise, but in a single-seater the front-engine is a non-starter without considerable asymmetry and complexity not needed on the mid engined car. Still, Indy Roadsters are IMO some of the most appealing racing cars ever built, as is the W154/163 Mercedes, Lotus T16 and a number of front-engined Juniors...

Is a typical F750 or clubmans car mid-engined or what?

[fines]

I hate the designation "mid-engine" - it's either front or rear, the driver's in the middle!

[David McKinney]

I'm with you on that, fines
The term always used to be rear-engined, until someone decided there should be some differentiation between cars with their engines over the wheels, which were rear-engined, and those with engines mounted in the middle of the car with the gearbox behind, which they thought should more correctly be termed mid-engined.
The fact of the matter is, the engine either goes in front of the driver or to his rear
End of

[Bonde]

...point taken, gents.

I'll use the term rear-engined from now on, as no-one in their right mind would ever design a racing car with the engine behind the rear axle line (although it has been know to happen...)

[fines]

... or, more to the point, the engine ahead of the front axle! By the definition of the "mid-engine" philosophers, there's no such thing as a front-engine!;) (Monaco-Trossi aside, perhaps...)

[Bonde]

...and various Panhard-engined DBs and FWD BMW and Zündapp-powered German 500 cc F3 cars and DKW-powered FWD Formula Juniors...

[Peter Leversedge]

I am one of those "Real Race Car Have The Engine In Front Of The Driver" guys, but one advantage of having the engine at the rear ["mid engined"] is more weight on the rear wheels gives better traction. My sprint cars where of course "front engined" but if you placed a bar under the frame half way between the front and rear axle and jacked the car up under the bar the front wheels came of the ground first. Also the action of the torque tube tended to lift the front of the car and transfer more weight to the rear wheels. No point in having 650 HP if you can't get it on the ground

[onelung]

The closer the driver to the back end/axle, the more/sooner he will be aware of that end sliding?

[cheapracer]

Originally posted by onelung
The closer the driver to the back end/axle, the more/sooner he will be aware of that end sliding?

Thats a good question and for me anyway, theres certainly a point for me thats as bad to be too far back as much as too far forward.

Some of the mid 80's race cars were most certainly mid engined with more engine and gearbox inbetween the wheels than driver.

[Allan Lupton]

Originally posted by onelung
The closer the driver to the back end/axle, the more/sooner he will be aware of that end sliding?

Yes and that's one reason why the Auto-Unions had their poor reputation. They were tail-happy anyway, but to get a V16 engine and a large fuel tank between driver and rear wheels, the driver was so near the front "axle" that he must have had very poor signals from the rear wheels.

[jatwarks]

Originally posted by Paolo
Yet a rear or mid engine seemed no problem in smaller cars, say 500cc Kiefts etc.

This, I believe, is part of the explanation. As engines became smaller and lighter their mass became a smaller proportion of the total mass of the car.

Given that the major masses in the car that the designer can position by choice are engine, gearbox, driver & fuel tanks, it makes sense to gather them around the centre of the car to enable it to change direction more readily. This also allows a shorter wheelbase, which has the same advantage.

The most compact way to package these masses is with the engine at the driver’s back with fuel tanks along each side.

As mentioned above, heavy engines of yore dominated the weight distribution. Placing the driver (& as much else as possible) behind the engine to balance the car moved the masses away from the centre, and so hindered rapid changes of direction.

I seem to gather that the opposition to a big rear-mid engine came from fear such cars would develop terminal oversteer due to engine weight at the back.

A heavy engine placed behind the driver does not necessarily move the weight distribution rearward: It depends on where the axles are. With the driver between the front wheels and a long wheelbase the car could still be ‘front heavy’ !

If suspension geometry was the real problem…

Not necessarily the problem. The geometry probably needed to be different, but perhaps the bigger problem was the designers & drivers adapting to the different needs of the ‘new’ layout.

The shorter, more compact packaging of the car gave the advantage of sharper, twitchier handling: And with the driver closer to the front wheels, sensitivity to the cars reactions had to become sharper too.

[Bonde]

The main reason, I think, most 500 cc F3 cars had rear engines was simply because that was the cheapest, simplest and lightest way to get a motorcycle engine with a motorcycle 'box to drive the rear wheels. For Coopers père et fils to then develop their hugely succesful rear-engined F3 concept into something bigger was almost inevitable (although they did do some front-engined detours along the way)...physics always win ind the end,

[HiRich]

Originally posted by Bonde
The main reason, I think, most 500 cc F3 cars had rear engines was simply because that was the cheapest, simplest and lightest way to get a motorcycle engine with a motorcycle 'box to drive the rear wheels.

This much is true, but then combined with the fact that the cars were outrageously fast, leading pretty much everybody (except Paul Emery) to follow suit. For context, Moss' first flying lap of the Nurburgring in the Moss-Kieft prototype would have comfortably qualified him for the Grand Prix. This despite giving away a good 60mph on the straights.
You also had intense competition (in the UK at least) with 30-70 cars racing every week. Understanding of the principles, and technical development came on leaps & bounds - weight & chassis stiffness, CoG posittion, roll stiffness & geometry, aero/cross-section all became major talking points.
In fact it's quite surprising how slow the bigger companies were to recognise the potential. If Harry Schell hadn't got himself mixed up in the Monaco shunt in 1950, I suspect things might have been very different.

Or perhaps not. It strikes me as strange, and unexplained, why Cooper's work on the first Vanwall seemed to ignore the lessons so clearly learned. Or why the Kieft F1 basically overlooked all the success of the spaceframe chassis used by Moss & Parker (a different design team, but the clues were all there). Of all the designers, you would have expected these two to shoehorn a "proper" engine into a 500 frame, just to see what happens.

[Paolo]

Originally posted by onelung
The closer the driver to the back end/axle, the more/sooner he will be aware of that end sliding?

More exactly, the more the driver is away from the centre of rotation, the higher will be the lateral acceleration he experiences when the car changes his angular velocity .

If the driver sits exactly in the centre of rotation, he will experience no angular acceleration connected lateral acceleration.
Thus detecting changes in angular acceleration will be more difficult.

If he sits away from the centre of rotation he will experience pure angular acceleration plus a related lateral acceleration: his brain will have a greater quantity of less noisy data on which to operate.

[Paolo]

Originally posted by Ray Bell
An important point...

Not only reduced distances, but also a change in fuel. This meant smaller quantities of fuel were required, so packaging their tanks into the car was easier.

Another benefit of the rear engined layout here was that more tanks could be fitted centrally in the chassis, so the balance of the car didn't change so much during a race.

Lancia D50 did this with a front engine, so I'd not see lateral tanks as an advantage typical of rear engined cars.

But maybe you mean it was possible to package more fuel in lateral cells when using a rear engine layout; of this, I must say, I am not sure.

[Racer.Demon]

Originally posted by Bonde
The main reason, I think, most 500 cc F3 cars had rear engines was simply because that was the cheapest, simplest and lightest way to get a motorcycle engine with a motorcycle 'box to drive the rear wheels. For Coopers père et fils to then develop their hugely succesful rear-engined F3 concept into something bigger was almost inevitable (although they did do some front-engined detours along the way)...physics always win ind the end,

They indeed reverted to the front-engined concept for the F2 car, and the planned Cooper-Godiva F1 car was front-engined as well. The return to the rear-engined lay-out for the new 1100cc sports car category was driven by practicality rather than by a company philosophy. It needed Black Jack to show them that an engine at the back was a viable concept for bigger cars.

[Racer.Demon]

Originally posted by Paolo
B) what did Cooper do that others (say, Bugatti) did not to have a working rear engine F1 ?

Over-engineering and just too much innovation all at once, usually.

Here's what I jotted down on all those early post-war rear-engined cars that failed:

http://8w.forix.com/...es-postwar.html

[cpbell]

Originally posted by Racer.Demon


Over-engineering and just too much innovation all at once, usually.

Here's what I jotted down on all those early post-war rear-engined cars that failed:

http://8w.forix.com/...es-postwar.html

I've only skimmed this great piece, but seeing the 1939/40 Gulf-Millers reminds me of a photo from the fatal practice accident at Indy I saw in a Miller biography which was kindly loaned to me a few months ago. Pretty grim sight. It does, however, prompt a question in my mind - if pannier tanks were banned at Indy then, what lead to rear-engined Coopers, Lotuses (Loti?) and others from being allowed to enter at the Brickyard in the 1960s, and using petrol at that, whose flammability surely led to the demise of Eddie Sachs and Dave McDonald in 1964 in an accident that surely bore a certain similarity to that of the Gulf-Miller?

[fines]

Pannier tanks weren't really banned, I wouldn't think so. It was more a question of "proper" protection, The 1941 Miller carried its fuel in the frame rails, which were large box section.

[cpbell]

Originally posted by fines
Pannier tanks weren't really banned, I wouldn't think so. It was more a question of "proper" protection, The 1941 Miller carried its fuel in the frame rails, which were large box section.

Agreed, but the tanks in the 1960s and 70s weren't located within the chassis - they had no protection at all other than the outer skin of the monocoque, which is hardly well-protected!

Back on-topic, I recall reading the argument that the best AU exponents between '34 and '39 were ex-motorcycle racers as they were used to twitchy handling. Cartainly, the fantastic colour George Monkhouse footage from Donington in '37 shows Rosemeyer's C-type getting very sideways through what I think is the Old Hairpin.

[Dale Harvey]

There is another point that seems to have been overlooked so far on this thread. Speed and ease of maintenance is better for the rear engined car compared to the front engine.
Dale.

[onelung]

More exactly, the more the driver is away from the centre of rotation, the higher will be the lateral acceleration he experiences when the car changes his angular velocity .

"more pedantically", rather than "more exactly"? ... all same, all same: certainly, we both agree on that point.

[Roger Clark]

Originally posted by Paolo



Lancia D50 did this with a front engine, so I'd not see lateral tanks as an advantage typical of rear engined cars.

As did Ferrari with the 553/555. They knew it didn't work with the tyres of the time and soon got rid of them when they got their hands on the Lancia.

[fbarrett]

Think 911!

[Milan Fistonic]

There was a Formula Junior that could only be described as rear-engined.

It was the Elpark, a one-off from California that had the engine (a Ford 105E) in the extreme tail, driving forward to the gearbox. The radiator was mounted above the gearbox.

That must have made for interesting handling.

[Robin Fairservice]

I would dare to suggest that the English constructors were slow to go to rear/mid engined race cars because they did not have access to suitable transmissions. It was only when people started to play with the Volkswagen, and then Citroen, gearboxes that viable, economic, transmissions, became available.

[Allan Lupton]

Originally posted by Robin Fairservice
I would dare to suggest that the English constructors were slow to go to rear/mid engined race cars because they did not have access to suitable transmissions. It was only when people started to play with the Volkswagen, and then Citroen, gearboxes that viable, economic, transmissions, became available.

A reasonable point, but (a) Citroen transmissions came in in 1934 and (b) there were many other fwd transaxles about in the 1930s if you looked across the channel (or Alvis and BSA if you didn't).
In the post-war period, the special-builders that became constructors were pretty catholic in their sources of parts (e.g. Cooper using Fiat bits) and would have known of all those pre-war German front-driven and Czech rear-engined cars.

[David McKinney]

And of course Citroen had a factory in the UK

[Paolo]

Originally posted by Roger Clark

As did Ferrari with the 553/555. They knew it didn't work with the tyres of the time and soon got rid of them when they got their hands on the Lancia.

Are you sure they got rid of lateral tanks? They seem very much present on every D50 I saw photographed...
Of course the concept was not passed to subsequent front engined Ferraris.

By the way, Racer Demon, that Forix article is a masterpiece, thanks for writing it.

[Bonde]

Robin, Allan,

Although at a later stage than 500cc F3, Elva used the DKW engine for their front engined Formula Junior, when they could have taken the whole DKW drive train and put in the back.

Having said that, it is true that there were not many high-performance fwd/rwd transaxles about in the fifties - the Citroën transaxle was always a bit 'on the edge' in the Coopers. Porsches were a possibility, though, in the 1950s.

As it was, the 'revolution' came from the grass roots, and there were many potential continental transaxles availble to the UK small sports car builder, but two-seaters didn't suffer quite the same disadvantages with a front engine as single-seaters did, so to me it almost seems inevitable that the path had to be through 500cc F3 as these were really the only small, 'grass roots' single seaters in the decade after WWII. Of course, if some of the wealthier UK or continental 'real' racing car manufacturers had donned their thinking caps they might have invested in a rear-engine transaxle for F1 style torque and power earlier...

I don't think the rear-engine 'revolution' could have been born in the US, since the Americans have always seemed to prefer racing cars with a strong relationship to road cars, and the USAC Roadsters seemed pretty well optimized for circle track racing at the time. Road racing in the US was pretty much a European transplant, so that had to wait for Old World developments - but there were quite a few succesful Porsches in the US in the fifties...

[cpbell]

Originally posted by Paolo


Are you sure they got rid of lateral tanks? They seem very much present on every D50 I saw photographed...
Of course the concept was not passed to subsequent front engined Ferraris.

By the way, Racer Demon, that Forix article is a masterpiece, thanks for writing it.

They blended them into the bodywork, and removed the tank structures within during the winter of '55-'56, therefore the true Lancia-Ferrari of '56 retained them merely as aerodynamic sponsons, with all fuel being stored in conventional tail tanks.

[Paolo]

Originally posted by cpbell


They blended them into the bodywork, and removed the tank structures within during the winter of '55-'56, therefore the true Lancia-Ferrari of '56 retained them merely as aerodynamic sponsons, with all fuel being stored in conventional tail tanks.

Had no idea of that, thanks for the info.

I guess the aero improvement wasn't much, since the idea died with the D50.

[cpbell]

Originally posted by Paolo


Had no idea of that, thanks for the info.

I guess the aero improvement wasn't much, since the idea died with the D50.

The impression I get is that they didn't have the time to redesign the car for 1956 without the structures as they housed the exhausts from the V8 engine. Presumably, replacing those 2 pairs of 4 stubs with a conventional single or twin-pipe arrangement would have affected engine output? The other thing I'm unsure about is whether the oil tank was moved to the tail in '56 or whether it remained in one of the sponsons.

[onelung]

Originally posted by cpbell


They blended them into the bodywork, and removed the tank structures within during the winter of '55-'56, therefore the true Lancia-Ferrari of '56 retained them merely as aerodynamic sponsons, with all fuel being stored in conventional tail tanks.

I'm not sure what is meant by the above: any photographs, please, to show the above mentioned "blending" so that we may be sure of exactly what is meant by that term?

[David McKinney]

Originally posted by onelung
I'm not sure what is meant by the above: any photographs, please, to show the above mentioned "blending" so that we may be sure of exactly what is meant by that term?

http://images.google...ch Images&gbv=2

[Paolo]

Original unblended variant:

http://images.google...l=h...l=en&sa=G


Later blended variant:

http://home.earthlin...&target=tlx_new

[Henri Greuter]

Originally posted by Racer.Demon


Over-engineering and just too much innovation all at once, usually.

Here's what I jotted down on all those early post-war rear-engined cars that failed:

http://8w.forix.com/...es-postwar.html

Fantastic piece Mattijs!!!

Maybe an interesting point to mention:

The gearbox in the Rocket-Offy of 1949 was of the same basic design and priciple as the ones used in the FWD Novis and Blue Crowns.

As for suitable gearboxes in mid-engined cars, Andy Granatelli had plans to built a mid engind Novi powered car by either John Cooper or Jack Brabham. They both turned him down because the gearboxes they used in their 2.5 l GP cars were based on the Citroen Traction Avant gearboxes and these were just about strong enough for dealing with a Climax 2.5 liter. But a Novi V8 with almost 3 times as much power and torque was definitely too much for the box.
Hence no mid-engined Novis for the time being.....


henri

[cpbell]

Originally posted by Paolo
Original unblended variant:

http://images.google...l=h...l=en&sa=G


Later blended variant:

http://home.earthlin...&target=tlx_new

Thanks Paolo, I was going to try scanning images from a book I have, but you saved me he job! It always seems very hair-raising to think that litre upon litre of jungle-juice fuel was being piped through one or more of those struts!

[Mark Godfrey]

Regarding some of the earlier comments on nomenclature: While the use of “rear-engine” in this context may have some old world charm for you cognoscenti, please do not suggest mid-engine is somehow wrong -- the term is descriptive, meaningful, and without peer.

Mid-engine is between the axles, rear-engine is aft of the rear axle and front is. . . at the front of the vehicle The lack of common term(s) to indicate placement before the front axle, as opposed to just behind it, matters not.

The popularity of a engine placement for any given form of road or race vehicle does not alter proper use of the terms, nor would the possibility that mid-engine was not in your automotive lexicon prior to 1970.

Mark

[fines]

I thought the Novis were mid-engined all along! Didn't they have the engine between the axles?


EDIT: this was originally posted as an answer to Henri's post, but with Mark's post accidentally in between, it really highlights the nonsense of the term "mid-engine"...

Proper use of terms is: front-engine and rear-engine. Smokey Yunick's side-car was mid-engine, and modern Super Modifieds are also, but there has never been a mid-engined Grand Prix car!

[Roger Clark]

Originally posted by cpbell


They blended them into the bodywork, and removed the tank structures within during the winter of '55-'56, therefore the true Lancia-Ferrari of '56 retained them merely as aerodynamic sponsons, with all fuel being stored in conventional tail tanks.

Not during the winter. The definitive 1956 car with no fuel in the sponsons didn't appear until the Syracuse Grand Prix.

[Mark Godfrey]

Michael, I am not the expert, but most of the Novi V-8s seem to be obviously mounted at the front of the vehicle.

Are you suggesting mid-engine should refer to placement next to the driver? Is the meaning contextual in your book, and differs between purpose built race vehicles and road cars? Are Porsche, McLaren, all the other makers and most English language media, misinformed regarding the designation?

Mark

[cpbell]

Originally posted by Roger Clark

Not during the winter. The definitive 1956 car with no fuel in the sponsons didn't appear until the Syracuse Grand Prix.

Oops, thanks for the correction. I suppose the delay was due to the handover of cars and equipment from Lancia not taking-place until late in 1955?

[fines]

Originally posted by Mark Godfrey
Michael, I am not the expert, but most of the Novi V-8s seem to be obviously mounted at the front of the vehicle.

Are you suggesting mid-engine should refer to placement next to the driver? Is the meaning contextual in your book, and differs between purpose built race vehicles and road cars? Are Porsche, McLaren, all the other makers and most English language media, misinformed regarding the designation?

Mark

Not so much misinformed as misguided!

If the definition of a mid-engine is "engine between axles" (as you posted, and actually everybody using the designation says), then the Novi clearly was mid-engined!

To paraphrase, I am not the expert, but most of the so-called mid-engines seem to have their engines obviously mounted at the rear of the vehicle.

[Bonde]

FWIW, I would, in normal banter over a pint, call a Porsche 911 rear-engined and a Porsche 917 mid-engined.

How I would verbally distinguish engine location between a Renault 16 and a Renault 18 would require a longer sentence, methinks :

[Roger Clark]

Originally posted by cpbell


Oops, thanks for the correction. I suppose the delay was due to the handover of cars and equipment from Lancia not taking-place until late in 1955?

Not really. It was more that they took time to find out what worked and what didn't. Ferrari did a lot of experimentation over the winter and took a huge variety of cars to Argentina: a standard Lancia, two modified Lancias with fuel in the tail but some still in the sponsons, a Super Squalo with a Lancia engine (!) a standard Super Squalo and a Super Squalo with the fuel moved to the tail. One of the modified Lancias had the modified rear suspension that became standard on the 1956 cars.