The Fighting '40s
The 1940s is an interesting era for cars of all nationalities. It was an era of a lot of experiments, some successful like the Traction Avant and some failures like Crosley. This is the era where cars began emerging from their extremely primitive roots and started to look like and be designed like the machines we know today.
Unfortunately, because this decade is a major changeover point and because the first half was consumed by a massive World War II, some ancient technologies that would have probably been ditched in the early years stayed around well into the 1950s. This was because all car manufacture ceased in 1943, 1944, and 1945 in the United States as the automakers’ were conscripted into making tanks, airplanes, and trucks for the war effort. No production, no new designs, no progress. Until late 1948, US automakers were still selling cars that were essentially mid to late 1930s designs.
What does this mean for automation? You are actually going to have a hard time making truly realistic cars from this era, but you can still come close.
Also, because of how many technologies and design practices arose or went dodo in this era, this is going to be a VERY trivia heavy post.
Platform and Chassis
Even despite cars really coming of age in the 1930s and 1940s, they were still primitive. This is likely would you would see of a typical, if slightly outdated, American car in the 1940s.
Steel. Nuff said.
I am not aware of any American car that uses aluminium for its body work in the 1940s. However here is something you WOULD see an car body made out of – wood.
Nope not joking. 100% serious. Have you ever heard the term “woodie” used for a station wagon / estate car? This is where it comes from. Old station wagon designs before about 1950 often used wood paneling so they got dubbed “woodies”. Incidentally, this is why the Chevrolet Suburban (and yes that nameplate has been around since the 1930s believe it or not) was a big deal. The Suburban was the first popular, mass produced station wagon design to use steel paneling, meaning it was exceedingly durable and could take a lot more abuse than the classic woodies. And of course trucks would have often have wooden beds as well.
Now wood is lighter than steel, obviously, so if you are trying to simulate wooden body work, aluminium paneling might be an appropriate choice.
Virtually all American cars of the 1940s were of the body-on-frame construction using ladder chassis. Spaceframe could be justified if you are going for something small / limited production.
Interestingly enough, the first American unibody car is actually produced in this era: the Nash 600. The car’s unique construction (for this era at least) made it lighter than other cars and so it got better fuel economy. How much better? Well Nash claimed 30 MPG which combined with its 20 gallon tank would mean a 600 mile range, hence the name “600”. I would be skeptical of these figures though. Just saying.
Steel. Again, nuff said.
Galvanized steel might be seen on some trucks.
Dependent front suspension designs weren’t dead yet. Early 1940s designs still sometimes had solid axles in the front. Coil versus leaf spring depends on manufacturer preference – both were used – so that’s up to you. However leaf springs were the more common choice because of their simplicity.
Independent front suspensions had become commonplace on premium and luxury vehicles and were making their way in to many standard designs as well. Double wishbone is all that automation has to offer which is fine considering it was a commonly used design. But in the early 1940s at least, another common design is one which we DON’T have access to, which is the Dubonnet suspension, also called the “knee-action” suspension by GM. Essentially its a trailing link design that uses a coil spring.
Anyways, independent front suspensions were common on luxury cars and had alreayd made good headway into standard cars at the start of this era.
Rear suspensions on the other hand were exclusively solid axle. If someone can point me to an American design with an independent rear, I would be very surprised.
Engines are by far one of the most interesting things about 1940s American cars because unlike the 1950s, 1960s, and 1970s, engine design wasn’t considered a solved problem yet. Any of the following were seen in American designs, commonly even:
- 90 degree V8
- And yes even V16s
And here is an exceedingly common 1940s American engine that you can’t build in Automation
Ahhh! Tell me that doesn’t just have a nice ring to it… “straight eight.”
As far as exceptions go, well, none really. 1940s American cars had a broad gamut of engines as we have seen above. Pretty much the only thing you wouldn’t see – to my knowledge anyways – would be boxers.
Which to use in what kind of car:
Straight-4 would make an excellent entry level engine. This was most commonly used by Willys Overland, makers of the world famous Willys MB “Jeep”. Used in their entry-level trucks and passenger cars. Also the only engine used by one very odd American manufacturer, Crosley, which was making cars one might confuse for a Renault, Citroen, or Volkswagen because they were tiny and that is not even by American standards.
Straight-6 should be your go-to design for a typical 1940s American car. This was the base engine on virtually everything, cars and trucks alike, made by the Big Three (Ford, GM, Chrysler) and most of the small independents like Nash and Studebaker as well.
Straight-8 If you could make it WHICH YOU CANNOT, this would be typically seen on premium and luxury vehicles, stuff like a Pontiac, Hudson, Kaiser, or Packard. Pretty much the only US automaker to never use a straight-8 design was perhaps surprisingly Ford.
V8 was sometimes seen as an optional engine on standard makes and some trucks, usually Fords. Generally, V8s are luxury car engines though which is why the Ford Flathead V8 was such a big deal. You could get a luxury car engine in your cheapo Ford. A V8 in the 40s was de facto for luxury cars.
V12 top-of-the-line luxury cars in the 1940s, such as Lincolns did use V12s. These were reserved to their halo models, however.
V16 1940 did mark the last year of the famous Cadillac V-16 but if you are going for all-out absurd luxury, there is a historical justification for it and it wouldn’t be far fetched.
And with American V8s you ALWAYS use a crossplane crankshaft! Cadillac were the ones who pioneered this afterall.
Fun fact about V16s: Chrysler was developing a V16 design during World War II for the US military and intended for next-generation ultra-high performance piston engine fighter aircraft. Jets came of age during World War II meaning the design never saw the light of day. Much of the research that went into it however found its way into Chrysler’s post-War V8 designs, one element of which is to this day a marketing gimmick for them – the hemispherical combustion chamber.
Valvetrain tech in the 1940s was still quite primitive. First of all, many if not most of the engines made during this era used sidevalve designs which we cannot build in Automation. We are limited to strictly variations of overhead valves whether its pushrod, overhead cam, or dual overhead cam.
That being said, the pushrod overhead valve design was common, particularly in straight-6 designs. V designs more typically used sidelvalves because it was simpler and many manufacturers stuck to sidevalve designs in general.
If you really want the true 1940s American car engine (the fact that you can’t notwithstanding), one of the ways you can simulate sidevalve designs is by negative quality spam on either pushrod OHV or direct-acting overhead cam. There is an argument to be had either way.
Our good old friend Crosley was the only exception this. They were the first American manufacturer to use an overhead cam, specifically a direct-acting overhead cam, on their engines in 1946.
Displacements of American engines in the 1940s were somewhat more modest compared to the 50s and 60s, capping at about 5.5L in passenger cars and light trucks:
Straight-4s had finally gotten away from the absurd displacements of the early years and were usually around 2.0L. The Crosley straight-4 was odd for an American design however at just 750cc.
Straight-6s and Straight-8s were typically seen between 3.0L and 5.0L though some examples like the Chrysler Straight-8 did go slightly above to about 5.5L.
V8 and V12s were usually between 3.5L and 5.5L. Cadillac V8s did go has high as 5.7L
The Cadillac V16 was somewhat absurd at 7.1L but it was a holdout from the 1930s when such displacements were common.
An important note on bore and stroke: most 1940s American designs were significantly undersquare i.e. having a larger stroke than bore. How significant? Normally at least 10mm and as much as 35 mm larger stroke than bore.
Late 1940s post-War designs are when we start to see the transition to square or oversquare designs.
EDIT: Another note on V8s here. 1948 and 1949 mark the birth of the first generation of the muscle car era V8s. So for a late 1940s V8, it would be acceptable for it to be designed with up to about 7.0L of displacement in mind but still only being about 5.5L in its initial configuration.
Cast iron. Nuff said. The only except that I know of is the Crosley engine which was made of… copper? Yeah Crosley is frickin weird.
All I can say is Ooof.
Most engines were running just one single-barrel carburetor. Some luxury and performance engines would see dual or triple carburetors, particularly if they were long engines like straight-8s or V12s.
AFR? Give up and cry: 13.5ish to 1 or richer.
See my post on carburetor tuning for the full explanation.
But that being said, it doesn’t really matter. 1940s engines were low revving torque monsters. Most of them didn’t go above 4000 RPM and often topped out at about 3500.
Speaking of which lets talk about
Or Kilowatts. Whatever… same thing.
The power that 1940s engines make can be summarized as whatever the engine makes is enough!
Actual power figures from this era are hard to come by and if you do, they are likely obtained by a whole bunch of non-standardized practices. The power figures we do have though are nonetheless not impressive.
This means that its hard to say for certain what kind of power you should expect to make except that whatever you’re modern brain thinks is appropriate probably needs to be knocked down a couple notches. Most engines were only making up to or slightly exceeding 100 hp. For large displacement luxury engines, maybe upwards of 150 hp. Don’t spend your time trying to make big numbers though or even really doing much tuning at all.
That actually feeds nicely into my next point:
Tubular headers were pretty much only seen on race cars!
Everything production used cast logs, or maybe short cast. I would further argue that 1940s engines were so strangled that if you are trying to simulate a sidevalve design say, a cast log exhaust header goes a long way towards doing that.
Virtually all American cars and trucks of the 1940s were RWD. The only real exceptions are some trucks and offroaders like the famous Willys MB “Jeep” and the post-War Jeep truck which were 4x4s.
Also, virtually all American cars used 3-speed manuals. Some trucks and offroaders had 4-speed manuals as an option. The only exceptions that I know of are irrelevant because Automation won’t let you build what they had. I am referring of course to the GM Hydramatic transmission found in Cadillacs and Oldsmobiles.
Yes. GM was making an automatic transmission in 1939. And it had four forward gears! How about that?
Wheels and Tires
Like carburetors, all I can say here is Ooof.
American cars of the 1940s typically used 5 to 7 inch, or 125 to 185 mm, wide tires with between a 90 and 110 profile sidewall. Ouch!
- Entry level cars
- 125 - 145 mm tires
- 14 or 15 inch wheels
- Standard / large / entry level luxury cars
- 145 - 165 mm tires
- 15 or 16 inch wheels
- Halo luxury / limousine
- 165 - 185 mm tires
- 16 inch wheels
Trucks would follow similar guidelines but larger trucks and some offroaders would use as large as 18 inch wheels and stick to the 100-110 profile range because load capacity and such. That oh so famous Willys MB “Jeep” uses a 17 inch wheel for instance.
Oh god WHY?
1940s brake tech was bad, bad, bad, bad, BAD. Of course cars were lighter and much easier to stop. But that doesn’t change the fact that 9, 10, and 11 inch drums brakes are bad. However, asbestos brake shoes were a thing and if you didn’t know, asbestos brake linings
give you cancer have excellent stopping power. You could lock wheels if you were really trying.
But just be warned. Shit is bad.
- How much brake fade are you going to have? All of it.
- How much stopping power are you going to have? None of it.
What aerodynamics? Don’t be putting wings, lips, or any of that hoopla on your cars though. A few quality points in aero at most.
That being said, Chrysler’s Airstream model was a big deal because it was perhaps the first mass produced American car to be styled with aerodynamics in mind.
Interior and Amenities
Your selection of interior entirely depends on what you want the car to be. But remember this:
RADIOS WERE FRICKIN REGAL!
You would only see them on halo luxury cars, and then only as an option.
Automotive safety glass was pioneered during this era and was one of the first safety features to be included widely in cars. So especially on late 1940s designs, you should be selecting Standard 40s safety at least.
And to my knowledge, the first cars with power steering don’t show up until the mid 1950s so that is irrelevant.
Well, Automation makes most of your selections for you because, well, there really wasn’t anything else around.
Keep this in mind with 1940s cars – they were still being made with the expectation that they would be going places without paved roads. So as a result, suspension tuning was very soft and mushy and ride heights were large. Spring frequencies typically fell between 1.0 and 1.5 Hz, damping around 0.2 - 0.3 and at this point, I am just going to defer you to my other post on suspension tuning
Because I talk about all of this and more which will be relevant in later eras. The TLDR is alreayd laid out above save for one thing: NEVER BELOW 1.0 HZ! It causes motion sickness.
AND NO SWAY BARS!
No no. You don’t get those yet.
As always, hope this helps! Enjoy.