Today we’re going to take a deep dive on the internet and look at some of the most insane engines you’ve never heard of.
This list includes a little bit of everything and the last engine is absolutely mental, so you’ll want to stick around until the end.
#1 Hayabusa V8
Okay, so you know the Hayabusa? Suzuki’s mammoth a sports bike that ruled the streets for years and years until the S1000RR and H2 hit the streets?
Well, I’m sure you’ve seen videos of the Hayabusa engine swapped into things like go-karts and smart cars. It might not make any torque but it sounds cool and can pretty easily make over 200hp from its 1300ccs of displacement.
But, do you know what’s better than one Hayabusa engine? Two of them smashed together into one unholy V8 engine.
I don’t know who comes up with these ideas, but I want whatever drugs they’re on because this both genius and mildly terrifying.
Now the idea of smashing two Hayabusa engines together to make a V8 engine is something that has actually been done by multiple companies, with a mixed bag of success.
One company that has done this is Radical Sportscars. Well, some of their crazy customers wanted more power than what their cars were currently outputting, so they developed a Hayabusa V8.
Their base engine is a 2.7L V8 that revs up to an insane 10,500 RPM and makes 400 horsepower, with a tuned variant also being available at 440hp.
We’re talking about the power of a 5.0L Coyote Mustang from a 2.7L V8. That’s absolutely insane.
But, for those of you out there with more balls than brains, they also make a 3.2L version of this Hayabusa V8 that outputs an absolutely absurd 500hp.
Another company that’s put together a Hayabusa V8 is JFC, with their base engine being a 3.0L naturally aspirated engine outputting 460hp and 280lb-ft of torque, with a long block that only weighs 200lbs.
I’m not even kidding you, this is a 260lb engine that most people can deadlift. But, that’s not even their top-of-the-line engine.
For those of you who are absolutely psychos with very expensive addictions to horsepower, JFC offers their 2.8L twin-turbo Hayabusa V8.
Now this variant of their engine is a 90-degree, flatplane crank with the same insane rev limit of 10,500RPM, but with the addition of two turbochargers, they managed to crank the power all the way up to 785hp and 505lb-ft of torque.
All of that is in a package small enough to shove into just about any car out there.
Of course, the biggest problem facing a Hayabusa V8, or any custom engine that puts two inline engines together to make one V engine, is that it generally requires a custom-made block, and that gets pretty expensive.
Generally speaking, these Hayabusa engines range from as low as $30,000 up to over $50,000.
It might not be a $500 junkyard 4.8L iron block LS, but for those of you out there who like burning money, a Hayabusa V8 is out there with your name on it.
#2 Toyota 1JZ V12
Alright, that’s enough of the Hayabusa V8, let’s take a look at an engine that’s based on the same principle of smashing two inline engines together to create one larger engine, but this time around it’s two inline-six engines smashed into one V12.
And what better engine to base this idea on than the Toyota 2JZ? Because if you thought Supra fanboys couldn’t get any worse, wait until they find out about the 2JZ V12.
Okay, I lied a little, this engine is actually based on the 1JZ and not the 2JZ, but considering how similar they are at the end of the day, we’ll just run with it.
Now this ridiculous idea was put together by one mad scientist by the name of Don Groff. I don’t think he’s actually a scientist, but he’s definitely a madman.
The earliest bits of this idea can be found on some forums from 2014 with an outline as follows:
- A block made from cutting the bottom end off two 1JZ engines
- A machined, welded, stress-relieved, and aligned bore crankcase with a 120-degree V angle.
- A custom-made crankshaft from Scat with small-block Chevy main bearings and Honda rod bearings.
- One cylinder head mounted the wrong way so the exhaust ports are all in the center of the V
- And a horsepower target of 800hp
Fast forward to today and that entire outline was pretty well followed, with a custom crankcase that Don designed, developed, and fabricated himself, and twin turbos strapped to it because why not?
The result? One incredible sounding V12 that sounds surprisingly similar to the typical Toyota inline-six sound, but with a twist.
The final result of all this madness is a pretty impressive power output of 810HP and 700lb-ft on E85 fuel.
Now I know you might be thinking to yourself, that power level seems a little underwhelming considering there are plenty of 2JZ engines out there making similar amounts of power with half the cylinders and displacement of this V12.
While that’s true, this certainly makes more torque and has a more usable power band than a 1JZ or 2JZ making similar power levels.
Plus, you have to remember, that building custom block engines is incredibly expensive, and you’d rather not push the boost to the max and explode your very expensive and time-consuming creation.
Could this 1JZ V12 make more power? I’m sure it could. Is it worth pushing the boundaries of what’s possible? Probably not. Either way, this thing is pretty wild.
#3 Honda K48 V8
Now this next engine is one that we’ve actually previously looked at on this channel about three years ago.
In fact, we interviewed the madman behind this creation, Craig Williams, in that video, so if you want a really in-depth look at this engine, I’d recommend checking out that video.
Anyways, what we’re looking at here is not just one, but two Honda K24 engines stuck together with a custom block to create a Honda K48 V8 engine.
But, this engine is more than just a custom block with two Honda cylinder heads.
The entire thing, top to bottom, is specially designed with performance, weight, size, and cost accounted for.
You see, one of Craig’s goals with the K48 engine is to make it as affordable as possible, and with that came some unique choices, such as using non-mirrored Honda heads.
What do I mean by this? Well, a typical V8 engine would have the full timing assembly at the front or sometimes the back of the engine, but with the K48, the timing system is on both the front and the back of the engine.
The reason for this design is that one of the heads has to be flipped in order to have the exhaust ports in the center of the V.
Rather than designing this engine with a very expensive custom-designed cylinder head for one side of the engine, Craig opted to just use two stock Honda heads and simply turn one around in order to save cost.
And that’s just one wild feature of this engine. In total, this design has gone through over a dozen major design changes, and every single day it gets closer to becoming a reality.
The end goal is to create an engine that produces around 700 to 800 horsepower naturally aspirated from its 4.8L displacement.
I know that might sound like a crazy and unrealistic power figure, but considering how much design work has gone into this engine and how well Honda’s heads flow, it’s more than achievable.
Unfortunately, Craig Williams, the madman behind all of this, has had some pretty severe medical setbacks that have made continuing with this project much more difficult both physically and financially, as he has been diagnosed with Parkinson’s and was told he had anywhere from 5 to 8 years left to live, although another hospital here in Phoenix gave him a non-terminal diagnosis and actually said he’s getting better.
Regardless, of whether Craig’s Parkinsons is terminal or not, he has continued with this project and hopes to bring it into the real world soon.
Be sure to check out his Instagram, Neutron Engines, where he regularly shares in-depth design changes down to the smallest details.
He also sells merch on his website that helps fund this project if you want to pitch in, so be sure to go check that out too.
#4 Volkswagen VR5
Okay, so moving on, let’s aim our sights at Volkswagen and one of the weirdest automotive engines I’ve ever seen, and that’s their V5 or VR5 engine.
Now this is based on the Volkswagen VR6, which itself is actually a pretty unique and interesting V6 engine that uses a single-cylinder head rather than two separate heads.
Volkswagen made this possible by reducing the V angle to as little as 10.5 degrees.
Now whether or not you want to call this a V6 or a staggered six, there is no denying that it’s a pretty interesting and unique design.
So what way to make it better, than to make it worse? And that’s where the VR5 comes in.
Volkswagen effectively took a VR6 engine and just removed a single cylinder, leaving behind an engine with three cylinders on the bottom bank and two cylinders on the top bank.
The question though, is why do this? Why take one cylinder off of a VR6 engine? Well, frankly there aren’t any great answers to that question.
Part of it is that Volkswagen wanted something between their four-cylinder engines of the time, which were generally kind of gutless, and their VR6 engine, which was considerably larger and maybe made too much power for some commuter type of applications.
What is interesting is that the VR5 has the same firing order as an inline-five-cylinder engine, but because it’s smashed together in the way that it is, it ends up creating a kind of circular firing order.
Now unfortunately, that results in the engine being fairly unbalanced, which ultimately results in some weird and fairly harsh vibrations that you might not experience in a standard inline 5-cylinder engine.
This isn’t great because, generally speaking, inline-5 engines are more unbalanced than something like an inline-6 cylinder.
Either way, the idea of the VR5 is pretty wild, although it was pretty unsuccessful and barely made it through the 90s and into the 2000s before Volkswagen killed it off.
#5 Synergy V8
Now this next engine is another one we’ve actually covered on this channel before, but it’s worth putting on this list, because well, it’s awesome.
And this is another engine that’s based on a four-cylinder motorcycle engine smashed into one unholy V8.
What we’re talking about is the Synergy V8. But, what makes this different from the Hayabusa V8 is that we’ve seen this engine have quite a bit of real-world testing in none other than the Subaru BRZ.
Because if you thought the BRZ was already lacking in torque, it’s possible to make it even worse.
On a more serious note, this engine is based on the Kawasaki ZX12r engine and actually produces more torque than the FA20 you’d normally find in a BRZ, which isn’t particularly hard to do considering a Milwaukee power tool makes more torque.
Like the other custom V8 engines we’ve covered on the list so far, this engine uses a custom CNC block, but this time around with two ZX12r cylinder heads bolted up to it.
It’s configured as a 90-degree V8, which normally would take up a massive amount of space, but considering the final displacement is just 2.4L, the engine itself is actually quite small.
Understandably, the crankshaft is custom made, as it has twice as many pistons to deal with as compared to the standard ZX12r crankshaft, and because the standard ZX12r crankshaft is a flatplane crankshaft, that carries over to this engine as well.
That all equals out to 367hp at 10,600RPM, 200lb-ft of torque at 8000RPM, with a ridiculously high redline of 11,600RPM.
As a company, Synergy does a lot of things, from engine design and development, simulation, engine testing, parts prototyping, and a lot more.
And for all my Euro bike guys out there, you can rejoice at the fact that they also make a similar engine based on the S1000RR engine.
Other than being awesome, the real benefit to swapping this engine in something like a BRZ is actually the weight savings, with the JUZ BRZ engine coming in 66lbs lighter than the FA20 that they pulled out, plus an even lower center of gravity and obviously more power.
And much like the K48 we looked at earlier, this engine also uses a one-cylinder head mounted backwards to save on engine cost, but it’s not like it really saved must, because a fully dressed package for a BRZ comes in at a whopping $70,000.
But to be fair, that’s not that bad for a custom engine that bolts right up to your stock transmission and isn’t hard to get to work with all your factory electronics.
Synergy also makes more powerful versions of this engine, such as the 3.0L variant, which outputs 515hp naturally aspirated.
And more important than anything, especially for this kind of money, is that this thing sounds incredible.
#6 Subaru Flat-12 F1 Engine
Okay so as most of you out there know, Subaru has a pretty impressive legacy of rally racing. During the the 1990s and 2000s they were one of the dominant players in the World Rally Championship.
And although they’re not nearly as involved in racing as they once were, that racing heritage is what helped them sell cars like the WRX for as long as they have, especially considering the power level hasn’t really changed in 20 years.
But, what if I told you that they once tried to venture into the world of Formula One?
I suppose it’s a logical step after having such dominant success in the world of rally racing, but unfortunately, their Formula One engine ended up being one of the worst marks in Subaru’s history.
Now this engine came as a collaboration between Motori Moderni and Subaru, as Subaru kind of needed someone with Formula One experience to help them get their engines on track and make sure they don’t explode in the process.
At that point in time, and still, to this day, Subaru was best known for their flat four “boxer” engines.
So, why not just stick with the boxer layout and simply triple the amount of cylinders? Well, that’s exactly what they did, putting together a 3.5L Flat-12 engine.
Unfortunately, the 3.5-liter flat-12 developed by the Subaru/Motori Moderni partnership basically took all the negatives of the boxer engine and made it even worse.
For one, it was a massively heavy engine, coming in about 250lbs heavier than a comparable Formula One engine, but that was made even worse by the fact that it only made about 550hp, which was as much as 100hp less than some of their competition.
On top of those two problems which already basically made this the worst engine on the field, the dimensions for this engine were pretty bad and required reworking the aerodynamics of the Subaru works cars, meaning this car also had some of the worst aero on the field.
And understandably, the Subaru F1 car absolutely sucked. After 8 races of trying to pre-qualify for an event, Subaru called it quits and never returned to F1.
While this engine was a complete failure in every aspect, it’s still wild to think that there are Subaru flat-12 F1 engines out there somewhere.