These Are Some Of The Smallest Big-Block Engines Ever Built

In the ’60s, America developed some cool, advanced engines, such as Pontiac’s overhead cam inline-6 or the jet-turbine in the Chrysler Turbine Car. Still, when push comes to shove, our first love is a good old naturally aspirated big block V8. Sure, we also enjoy forced induction systems and hybrids. No one is going to say that a Hellcat, GT500, ZR1, or E-Ray is anything but pure, undiluted America, but there’s a reason 1971 Hemi ‘Cuda convertibles sell for upwards of $3.5 million – and it’s not for the gas mileage.

There are so many spine-shivering big block V8s, including the LS6 454, ZL1 427, 426 Hemi, 429 Super Cobra Jet, and Super Duty 455, to name a few. However, we tend to equate big block with large displacement, but that’s not always the case. Think of it this way — big blocks carry greater potential for large displacements than small blocks because the larger the block, the easier it is to increase bore/stroke capaciousness. Manufacturers haven’t always done so, though. 

Take Chevrolet’s V8s as an example. This big block Chevy V8 is about 27 inches wide and around 32 inches long, while a small block is about 22 inches wide and a little over 28 inches long, yet there are 396 big blocks and 400 small blocks. Let’s start our list by checking out the tiniest Chevy big block ever made.

Chevrolet’s W-series big block now comes in a 632 cubic inch version with a Tesla Model S Plaid-ish 1,004 hp, but only as a crate motor. The last time customers could opt for such a giant hunk of iron in a passenger vehicle was in 2009, when Chevy’s 8.1L 496 cube Vortec V8 ended the big block era. Before that, the big block shook pavement as a 454 in 2500-series diesel-alternative form, a torque factory in the legendary 1500 454 SS pickup, a smogged-up LS4 during the early malaise era, and as the drag strip deforming LS5/LS6 in 1970/1971 Chevelles and Corvettes. 

Keep going back in time, and the Chevy big block shrinks to a 427, a 409, a 402, a 396, a 366, and even a 348, which doesn’t even match the swept volume of (arguably) the most famous small block, the 350. Admittedly, the timeline of displacements isn’t so simple; the 396 came after the 409 for example, but the W-series did begin as the adorably suggestive Turbo-Thrust 348 in 1958. 

As for the small block, it can get some incredible displacements, too. What started as a 265 has been punched out slowly but surely, with the most recognizable displacements being 283, 327, and 350 cubic inches. These days, small block displacements can easily dwarf those of vintage big blocks, with small block 427s and even 454s being fairly common. However, you might not have known that CFE Racing developed an astounding 600 cubic inch small block in 2013!

Look at the thickness of those cylinder walls! You could measure them in feet! This image from a teardown of a Ford 370 shared by YouTuber Midwestern Garage shows how crazy it is when big blocks have small displacements. The bore on a Ford 370 is 4.05″, while a 460 bore is nearly 4.5″. The 370 was designed for trucks and buses, where it could be found from 1977 to 1991. 

Of course, the 370 isn’t the smallest. There’s also the 330 cubic inch FE, which was actually designated an FT because it was part of the truck lineup of engines, which means it had a steel crank instead of a nodular iron one. However, the FE, surprisingly, is not considered by Ford to be a big block, but rather a medium block. The true big block Ford engine is the 385-series, which birthed the awesome 429 Boss and 429 Cobra Jet engines. 

While the 370 is the smallest 385-series engine, the biggest is the 460, which Ford put in everything from Thunderbirds to the F250 pickup truck. Some madlad even 460-swapped an Australian Ford Falcon. What’s odd is that Ford never made a 385 version of the 385-series. Sure, the name comes from the 3.85″ stroke, but why not make a 385 cube version, too? Probably because it’s unnecessary and would eat up time and money to develop. Let’s move on.

The sound team for Stephen King’s Christine — a car that rightfully haunts our nightmares – recorded a Ford 428 Super Cobra Jet because apparently the producers thought the 1958 Plymouth Fury’s 350 cubic inch Golden Commando didn’t sound aggressive enough. 

However, those B-series big block Chrysler 350s weren’t slouches, as putting out 305 horsepower in 1958 was no mean feat. Compression was 10:1 and the engine was fed by dual four-barrel carbs. While the B-series eventually ballooned to a nice round 400 cubic inches, it’s the 383 version that’s the most famous, with the 383 Magnum borrowing heads, intake, cams, and exhaust from the 440 Magnum to make 335 horses. The B-series lasted until 1978 as the aforementioned 400 incher, when it was discontinued for use in passenger vehicles alongside the taller deck RB 440. 

B and RB block size differences are best evidenced in the 1969 Barracuda. Plymouth figured out how to fit a power steering pump in the engine bay of ’69 383 Barracudas, barely, but the 440 models? Nope, that 440 was just big enough that a power steering pump was out of the question. Even a power brake booster was asking too much, which meant that 1969 440-powered ‘Cudas didn’t get air conditioning, power steering, or power brakes.

Sometimes multiple displacements from the same block is a feature rather than a byproduct of getting braver with bore limits. American Motors Corporation (AMC) designed its second generation V8 to span a wide range of displacements, from 290 cubes at the smallest in 1966, to 304, 343, 360, 390, and finally to 401 by 1971, and it could have gone to over 450 cubic inches if needed. American Motors probably needed a 450 to really compete with the performance of the Big Three — not that it would have saved the company, but it’s nice to go to a happy place rather than accept the reality of AMC’s derelict Detroit headquarters.

Second-gen AMC V8s may have a surprising plethora of displacements, but the first generation AMC V8 may be the champ of tiny bore and large block. Chevy big blocks have a bore spacing of 4.84″, and small blocks have a bore spacing of 4.4″, while AMC gen-1 V8s have a bore spacing of 4.75″ — definitely closer to big block territory. Yet, that engine debuted in 1956 at a shockingly diminutive 250 cubic inches with a bore of just 3.5″. 

If Ford 370 cylinder walls can be measured in feet, AMC 250 cylinder walls can be measured in football fields. AMC did manage to punch it out to 327 cubic inches, though. 

The 426 Hemi is rightly called the Elephant due to its size and power. Still, it’s the first-gen Hemi that actually brings the most pounds and the fewest cubes. If you’re looking for a weighty engine with small displacement, it’s hard to beat the initial run of 331 Hemis. At 331 cubic inches, it’s dwarfed by the nearly 100-inch larger gen-II 426 Hemi. However, thanks to an integral bell housing, the 331 Hemi weighed a solid 1,000 pounds. Maybe this is cheating, but it’s hard to ignore the 331’s combination of heft and relatively tiny volume.

Discussing displacement is always fascinating because while it’s just one factor among many in determining an engine’s performance, it is almost universally the metric enthusiasts care about first. Manufacturers brag about the size of their engines and even base their cars’ naming conventions around displacement — or at least they used to. 

For instance, BMW used to name its cars with the series and the engine’s liters. Thus, a 3-series with a 2.8-liter inline-6 would be a 328. Mercedes did something similar, especially with AMG models. An E63  badge used to mean that the car had a 6.3-liter V8. Well, ok, it was actually a 6.2, but Germans have to round up displacements, for some legal reason. Of course, now it’s a 4.0-liter, so calling it a 63 is — as pointed out when we asked you for the cars with the most misleading names – as accurate as calling a Porsche Taycan a turbo.