In the world of cars, the method of producing power used to be increasing displacement, but as we’ve gone into the modern century and turbocharging is increasingly popular among manufacturers, extremely large engines have almost entirely been phased out in favor of smaller and more efficient engines.
And that got me thinking, what are the largest car engines ever used? So, let’s take rewind the clock and look at the biggest engine ever used in an automobile.
Defining the Outline
To start this off, we’re going to break this article into two pieces: in the first piece, we’ll look at the largest production car engine ever and for the second piece, we’ll look at the largest race car engine ever, and you’ll definitely want to stick around to the end because the race car engine is absolutely mind-blowing.
So, starting with the production car, things are a little bit confusing. If you look online, many websites defer to 8.4L V10 used in the Dodge Viper as the largest production car engine ever, but the thing is, there are much larger engines that were used by car manufacturers back in the day.
Because the definition of a “production car” changes depending on who you ask, I think there are two cars we should look at for this section of the article, and the first is the aforementioned 8.4L V10 from Dodge. But, before we look at that, let’s rewind the clock to 1920 when we find the true largest production car ever in the Pierce-Arrow Model 66.
Production Car #1: Pierce-Arrow Model 66
This particular automobile was produced for a fairly short span, lasting 1910 to 1918. At the heart of the Model 66 is a big ass 825 cubic inches inline-six engine. During this time, they had the Model 38, Model 48, and so on. The Model 66 in particular is named after the horsepower rating of 66 horsepower, which is the power figure that Pierce-Arrow had calculated when the car was new.
Since then, it’s been found out that the power is closer to 100 to 125hp, which for that time, was a pretty insane engineering feat. I think it’s also worth noting that upon initial release, this big inline-six was actually only 714 cubic inches and it wasn’t until a few years after the release that the displacement was increased to 825 cubic inches.
Because this engine is very old, it doesn’t really have any of the modern things you’re used to seeing on an engine, and what I mean by this is that this is a T head engine, meaning the valves are upside-down and sit very close to the cylinder. This kind of design has obviously been phased out since then, but it’s cool to see in this type of application.
In 1918, Pierce-Arrow made the ultimate version of the Model 66 by upgrading the engine with four valves per cylinder, rather than the standard two valves per cylinder, which also brought in a new upgraded cylinder head. With more power also came the need for more braking, so they also included four-wheel brakes on this upgraded version of the Model 66.
In 1918 Pierce only produced four cars with the four-valve engine and only one of them has survived as far we know. Moving on, let’s look at the 8.4L V10 in the Dodge Viper!
Production Car #2: Dodge Viper 8.4L V10
As you might already know, the Viper has long been one of the weirder performance cars in the US. Not because it doesn’t perform well, because it does perform excellently, but because it’s never really fit in anywhere. Really, its closest direct competitor is the Corvette, which has been a performance staple for decades.
The Viper, on the other hand, has come and gone multiple times with five generations of the Viper between 1991 and 2017. For this article, we’re looking at the fifth generation of the Viper which was available from 2013 to 2017 and comes equipped with 8,382cc of displacement which is a hair more than the third-generation Viper at 8285cc.
I’d like to note that the fourth-gen Viper shares the same displacement as the fifth-gen viper, but with a little bit less power. As far as I can tell, the fourth-gen and fifth-gen Viper share almost exactly the same engine, so if someone out there knows the exact differences between these two engines, drop a comment down letting me know.
As far as some basic specs, this is an all-aluminum V10 with an overhead valve design, meaning it uses one cam in the block with pushrods and rocker arms to push the valves. What’s particularly interesting is that this engine also features cam-in-cam variable valve timing, which is not something you saw often for overhead-valve engines.
Power output is rated at 650hp and 600lb-ft of torque, but that was later raised to 645hp. That power figure remains the same for all fifth-gen Viper models from the base up to the ACR.
Alright, enough of the Viper. Sure, it’s a cool car and I’d love to own one eventually, but let’s move on to something a little more interesting.
Race Car #1: Fiat S76
More specifically, let’s look at the Fiat S76, which houses the S76 engine and holds the record as the largest engine used in a racecar. Fiat developed the S76, which is also known as the S76 Recond and The Beast of Turin, as a car with one single purpose, and that was to take the land speed record which at that time, was held by Blitzen Benz.
They only built two of these cars, and one of them is actually still operable and has been seen as the Goodwood Festival of speed in recent years. Under the hood of the S76 is a ridiculous, 28.5-liter inline-four cylinder engine, pushing out a whopping 290hp at 1400pm and 2000lb-ft of torque.
The engine was later produced in a modified form for use in aircraft, but for this article, we’ll just look at the engine that was used in the S76 car. It uses four valves per cylinder, two spark plugs per cylinder, and strangely enough, it actually uses overhead cams.
Because of the lack of any real exhaust manifold, this thing shoots out some pretty insane flames when it’s running. Although, from old photos, it appears to have used an exhaust system at least part of the time, which is probably a good thing because shooting massive flames out of your hood just a few feet away from the open cockpit sounds a little dangerous.
Race Car #1: BMW Brutus
The last car I want to look at is a bit weird in the sense that it doesn’t quite fit in any category, because it’s not a production car and sort of a race car, but really it’s just more of a crazy experimental car, and that’s the BMW Brutus with a 47-liter V12 engine made by BMW. The engine’s original application was as an aircraft engine.
The engine has two different power outputs, with a short-term output of 750hp and a continuous output of 550hp, at least according to BMW. Strangely enough, the right bank of the engine and the left bank of the engine actually have different displacements due to different connecting rods.
One of the original with the Brutus was to reach 100km/h at an engine speed of 800rpm. It’s a strange goal, but nonetheless it was one of the goals. A couple of different drivers pushed the Brutus to its limits throughout the years, but only one driver managed to get up 200km/h.
The chassis is actually a 1908 American LaFrance firetruck chassis with a three-speed chain transmission which then sends power to the rear axle through a chain system.
I think it’s worth noting that the car isn’t technically a BMW, rather it’s just an experimental car that features a BMW engine. The BMW Brutus is currently in a museum in Germany where you can go see it. Unfortunately, a lot of info floating around is conflicting, so if anyone out there has crystal clear information on the Brutus, I’d love to hear more about it.