Exploring Ford’s Essex V6 and 255 V8: Forgotten Engines

Imagine this: you’re in a cluttered garage, the scent of old oil heavy in the air, and some friend of a friend mechanic is elbow deep under the hood, grumbling, “Well, it’s a Ford, but it’s not one of the good ones.” Welcome to the strange and sometimes disappointing world of Ford’s lesser-known engines. These power plants that never got the fanfare or hero worship of, say, a 302 or a big block 460. Today, let’s shine a light on two oddballs, the ones you only hear about when someone’s squinting in an old factory option list: the SX V6 and the 255 V8. Now, these engines aren’t the mighty Cleveland or the famed Windsor family members that everyone drools over at car shows. No, these are the forgotten kids at the family reunion. But before you turn away, consider this: these engines came to life during a time when Ford was trying to navigate new emissions regulations, stricter fuel economy rules, and the oil crisis panic. They’re like those weird cousins at Thanksgiving—awkward at first but full of fascinating stories. Want to break the ice?

Howdy folks, Ed here. Welcome back to Bullnose Garage. And so here’s the real question: why should you care? Well, because understanding these engines is like getting a secret peek into Ford’s inner thought process back then, an era defined by compromise, creativity, and a dash of desperation. And who knows, maybe one of these engines is the perfect quirky choice for your next project. It might not be a tire shredder, but it’ll definitely earn a nod and a chuckle at your next Cars and Coffee meetup. So crack open a cold one, settle in, and let’s give these overlooked motors their 15 minutes of fame.

Hello! So you might be asking, why lump these two misfits together? Well, both the SX V6 and the 255 V8 represent a particular historical moment for Ford. Picture the late 1970s to early ’80s: emission laws were tightening faster than a lug nut at a pit stop, gas mileage became the new Holy Grail, and automakers were scrambling to make cars cleaner and thriftier at the pump. The big thirsty V8s of the ’60s and early ’70s suddenly looked like dinosaurs, and Ford had to figure out something new, something that could pass regulations without guzzling gas like a frat house kegger. These engines were Ford’s attempts at that balancing act. The Essex and the 255 were part of the experimental toolkit, so to speak. Sure, they didn’t redefine performance or become icons of efficiency, but they do tell us a lot about how manufacturers scramble for answers. And let’s be honest, when you’re talking about unusual or offbeat Ford engines, these two tend to come up in the same breath. Neither has a big fan base or much love, and both carry that head-scratching, “Why did Ford do this?” mystique. Side by side, they paint a clearer picture of what was happening under the Blue Oval’s roof at the time.

And finally, for my fellow Bullnose enthusiasts—that’s Ford trucks between 1980 and ’86—there’s a practical reason. The 255 V8 actually showed up in some early Bullnose trucks, even if it wasn’t exactly a top choice. And the 3.8L SX V6 also made a brief appearance, but only in small numbers of light-duty F100s during the ’82 to ’82 model years. While neither engine became iconic, both reflect Ford’s willingness to roll the dice, even if those bets didn’t quite pay off. Understanding one gives context to the other, and together they make a perfect pair for this video.

The Ford SX V6 came onto the scene in the 1980s. Now keep in mind, I’m talking about the North American version made in the S6 engine plant in Windsor, Ontario, not the UK version made in Dagenham, Essex, starting in the ’60s. They are not the same, not even close, which can be confusing. So the, uh, the North American version first debuted in the 1982 Thunderbird, got put in the LTD, and later snuck into the Mustang lineup. This engine soldiered on through the ’90s and beyond, even showing up as a supercharged option in the Thunderbird Super Coupe. The final version, a longer-stroked 4.2L, ended its production in the 2007 F-150. I mentioned it’s used in Bullnose trucks earlier, but it wasn’t exactly common. While most F-series trucks of that era stuck with the stalwart inline sixes and V8s, the 3.8L SX V6 did appear in a small number of base model F100s, particularly in Canada. It was a rarity in the lineup and wasn’t offered in heavier-duty models. But that doesn’t mean the enthusiasts haven’t toyed with the idea or even attempted a swap. Thanks to its compact size and decent fuel economy for the time, produced in massive numbers, the SX V6 was a true workhorse in sedans and family haulers. Not flashy, but dependable.

In the early ’80s, carbureted versions were the norm, but eventually Ford embraced the FI on the platform, improving drivability and emissions over time. The SX V6 evolved. It started out in a 3.8L engine, which is 232 cubic inches, with a bore of 3.81 inches and a stroke of 3.39 inches. Later, it increased the stroke to 3.74 inches to create the 4.2L version, which is 256 cubic inches, which powered F-150s from ’97 to 2007. There was also a 3.9L version, which is 237 cubic inches, achieved by using a 3.4-inch stroke, which appeared in vehicles like the Ford Freestar and Mercury Monterey, but never made its way to trucks. In addition to its displacement variations, the SX V6 stuck under with updates to keep up with changing technology and regulations. Early versions ran on carburetors, as I said, but Ford introduced EFI in the 1980s and later sequential port injection, or SPI. These upgrades brought more precise fuel delivery, improving drivability, efficiency, and emissions. These advancements played a big role in keeping the Essex relevant well into the ’90s, even as competition increased.

The production SX is an iron block, iron-headed V6. Deck height for the SX V6 reportedly measures approximately 8.9 inches, though it’s a hard stat to nail down with any confidence. Compression ratios range from about 8.0 to 1 to 9.0 to 1, depending on the year and application. Perfect for regular pump gas. Horsepower in early configurations wasn’t exactly eye-popping, I think roughly 110 to 120 horsepower in its early days, though EFI models and supercharged variants pushed that number significantly higher later on. Torque usually landed in the low to mid-200 pound range, which is respectable for a V6 in that era. The firing order for the SX V6 is typically 1-4-2-5-3-6. Oil capacity runs about 4.5 to 5 quarts, and good old 10W30 or 10W40 is often recommended, though as always, check the specs for your particular year. Thanks to its relatively lightweight build compared to the small block V8, it’s a tempting choice for compact projects.

Now, nobody’s geeking out over the finer details like they do with classic Ford V8s, but the SX V6 is a short, stout little workhorse. For practicality, not racing glory. Pop the hood on a Ford of the right era, and if you see a compact V6 with iron heads, a front-mounted distributor (at least on older carbureted models), and the distinctive Ford blue or black engine paint, depending on the year, chances are you’re looking at an Essex. But your best bet for identifying it, as usual, is to check the engine stampings and casting numbers. The intake manifold and valve cover shape can also give it away. Short, wide valve covers and a modest intake practically scream SX.

As I already mentioned, the SX V6 primarily powered cars like the Ford LTD, Mustang, and Thunderbird. Mercury counterparts shared love too. For years, it was Ford’s go-to V6 for front-engine, rear-drive sedans and coupes, especially as emission standards tightened and the V8 dominance began to wane. In its later years, it even found a home under the hood of front-wheel-drive platforms like the Taurus and minivans like the Windstar, those versions sporting improved tech. Now, as for common issues? Overheating? Yep, that wasn’t unheard of, especially in certain setups. Head gasket failures were a notorious sore spot in some years, especially in the ’90s. Front-wheel-drive variants, timing cover leaks, worn-out timing chains, and intake manifold gasket leaks also popped up occasionally. Regular maintenance helps, but if you’re eyeing a used Essex, you’ll want to give it a solid once-over.

When it comes to transmissions behind the SX V6 in rear-wheel-drive configurations, Ford initially paired it with automatics like the C5 and later the AOD for models like certain Fox body Mustangs and Thunderbirds. As the platform evolved, newer automatic options like the AOD and 4R70W showed up in later applications, particularly in the ’90s Mustangs and Thunderbirds. They still carried the SX V6 for manual fans. The SX V6 occasionally got the T5 5-speed in Fox body and SN95 Mustangs, and the Thunderbird Super Coupe famously offered the M5R2 5-speed manual. These factory pairings gave you a menu of bolt-up options, no fabrication needed, as long as you’re sourcing from SX V6-equipped donor cars. However, it’s worth noting that the SX V6 uses a unique bell housing pattern different from the classic small block Ford V8. In other words, you just can’t grab a transmission meant for a 302 or a 351 and expect it to bolt on without an adapter. If you’re doing a swap or restoration, your best bet is to find a transmission originally designed for the Essex. Now, to make matters worse, the SX bell housing pattern is different between front-wheel-drive and rear-wheel-drive versions, so you need to keep that in mind if you’re looking to bolt one up.

Replacement parts? No problem. Gaskets, filters, belts, hoses are all easy to find. But don’t expect a bustling SX speed shop with high-lift cams or tricked-out cylinder heads. If you’re willing to dig, you might find some enthusiasts adapting Thunderbird Super Coupe parts, or you could get brave and try forced induction. For most builders, though, the SX V6 is a leave-it-stock and hope-for-good-gas-mileage engine. We’ll talk more about potential performance tweaks a little bit later. So the SX V6, in a nutshell, steady, reliable, but never spectacular—a, shall we say, practical chapter in Ford’s history. It served faithfully during a challenging time, never aiming to wow gearheads at the drag strip. If you’re building a light, fuel-efficient rig or just want something quirky to chat about at the next car show, it might be worth considering. Otherwise, it’s hard to argue against a more common and better-supported engine like the 302 or even the 289. But there’s a certain charm in breathing new life into a forgotten motor.

Now on to today’s other star player, the 255 V8. Ford introduced the 255 as part of its effort to downsize the Windsor engine family in the late 1970s, rolling into the early ’80s. The goal was to create a smaller, more efficient V8 in an era when fuel economy and emissions were top priorities. The 255 saw action from around 1980 to ’82 with a mix of Ford and Mercury full-size cars, and yes, it even found its way into some early Bullnose F-series trucks. But it never quite caught on. Most folks saw it as a shadow of the venerable 302. Production numbers were low, and the engine quietly faded into obscurity as Ford focused on more promising configurations. The 255 might just be the definition of “seemed like a good idea at the time.” These days, it’s more of a curiosity than anything else. Still, if you’re working on a factory-correct restoration of a 1980-82 F100 or a full-size car from that era, the 255 could be on your radar. It’s a piece of the puzzle; it helps us understand Ford’s strategy at the time: keep that V8 cache alive while also avoiding gas guzzling. And the results? Let’s just say they were mixed.

The 255 V8 came from a proud lineage of small block Ford engines, starting with the 221 and 260 in the early ’60s. These compact V8s were trailblazers in their day, setting the stage for the Windsor family, which included legends like the 302 and eventually the ill-fated 255. While the 221 and 260 succeeded by striking a balance between power and efficiency, the 255 faced an uphill battle two decades later, hampered by tougher emissions and fuel economy mandates. Its displacement, about 255 cubic inches or 4.2L, comes from a reduced bore compared to the 302. The deck height is the same as a 302 at 8.2 inches, so what you’ve got is essentially a 302 block with smaller internals and restrictive heads. Compression ratios were low in the 8.0 to 1 to 8.3 to 1 range. Horsepower hovered around 115 to 120 horsepower, and torque landed in the 190 to 200 lb-ft neighborhood. Not exactly numbers to get your heart racing. The block and heads are cast iron, sturdy enough, but those tiny valves—1.64 inches intake and 1.38 inches exhaust—choke airflow like it owes them money. The firing order is the same as other Windsor V8s, and oil capacity is around 5 quarts. The recommended grade, similar to other small block Fords, tends to be 30 or 40.

Just like the SX, it’s compact and lightweight for a V8, but that’s pretty much its only bragging right in the performance department. At first glance, the 255 looks a lot like a 302, which can even trip up seasoned gearheads. To be sure, you need to check casting numbers and measure bore and stroke. The heads are a giveaway; those small valve sizes are a dead ringer. And if you’re looking at a 1980 to ’82 Ford or Mercury with a V8 that feels suspiciously underpowered, it’s probably a 255. The 255 showed up in certain Fox body platforms, full-size Fords like the LTD and Crown Victoria predecessors, and crucially, it made an appearance in some early Bullnose F100 trucks. It was never widely celebrated, so it didn’t hang around very long. By the mid-’80s, Ford had moved on to better-performing, more reliable engines. So let’s call it like it is: the 255 is an underachiever designed for fuel economy and emissions compliance. It’s not speed. Acceleration is modest at best. It can cruise around town and handle daily driving, but don’t expect to win any drag races. The engine’s real job is being a placeholder, just something to fill the bay while Ford worked on better ideas. Adequate for its time, but it won’t exactly set your hair on fire.

Maintenance-wise, nothing special here—just your usual low-V8 stuff: timing chain wear, carb tuning headaches, and the occasional oil leak from the valve covers or oil pan. The main gripe is its lackluster performance. With routine maintenance, it runs smoothly, but don’t expect to find any hidden power without serious mods. Unlike the SX V6, the 255 shares the classic small block Ford bell housing pattern that’s been around since the 1960s. This means it works with a wide range of transmissions built for engines like the 289, 302, and 351. From the factory, the 255, during its short production window, was most often paired with automatic transmissions in full-size Ford and Mercury models and early Bullnose trucks. You typically find a C4 or its successor, the C5, bolted behind it. The C4 and C5 were three-speed automatics, Ford’s warhorse back then—simple and reliable. By 1980, Ford also introduced the AOD, which is automatic overdrive, in some applications. Certain full-size cars running the 255 used the AOD to squeeze out a few more miles per gallon on the highway. And while rare, some Fox body cars with a 255 also offered the SROD, which is single rail overdrive four-speed manual transmission. Thanks to the interchangeability of small block Ford bell housing patterns, it’s not out of the question to find one in the wild.

The real advantage here is that if you decide to swap or upgrade from the 255, or even just want a different transmission option, the classic small block Ford bolt pattern gives you a buffet of choices: T5 five-speeds, AOD, AOD 4R70W automatics, Tremec five or six speeds—all potential candidates with the right combination of flywheel, clutch if you’re going manual, and linkage. This makes transmission selection for the 255-powered project far more flexible than what you’d encounter with the SX V6. But if the SX was slim on performance parts, the 255 is downright bare. Sure, some 302 parts fit, but the tiny valves and low compression ratio mean you’re starting from a weaker baseline. You could swap heads, intake manifolds, and exhaust components from a 302, but by the time you do that, you might as well have started with a 302 and saved yourself the hassle. Basic tweaks and maybe a slightly better intake or exhaust are all you’re likely to bother with unless you’re just dead set on making a point.

So let’s say you’re that special kind of gearhead who loves a challenge. Maybe you don’t care that your engine isn’t exactly a darling in the performance community. Maybe you want to roll into a car show, pop the hood, and make people say, “Wait, what is that?” If that’s the case, the SX V6 or the 255 V8 could provide a unique canvas for your next build. Just know what you’re getting into. For the SX V6, there’s a precedent for forced induction—the Thunderbird Super Coupe and a supercharged variant of this engine. With some scavenging and creativity, you could replicate or adapt those components to build a snappy V6, focusing more on torque and uniqueness than sheer horsepower. Think of a lightweight Fox body Mustang with a supercharged SX V6, or even an oddball swap into a Ranger. Sure, it’ll need custom fabrication, and yes, tracking down performance parts will be an exercise in hair-pulling, but if you succeed, you’ll have a story worth telling at every meet and greet. The SX’s lighter weight could also improve handling in smaller vehicles. Imagine a nimble autocross machine that stands out precisely because it’s not running the usual small block V8.

So the 255 V8, if you’re really committed, you could improve it with better flowing 302 heads, a mild performance cam, and freer breathing intake and exhaust. This could transform a wheezy old economy motor into something at least respectable. If you’re building a period-correct sleeper, stuffing it into a classic sedan or a vintage import to turn heads, it might just have enough charm to make sense. Or consider a small, all-lightweight roadster that could benefit from a compact V8. The 255 could be a fun project in a build where every pound matters, and all you’re after is that smooth V8 rumble, not huge horsepower. Are these mainstream performance choices? Absolutely not. You’ll work harder, spend more, and probably get less performance than you would with a common engine like a 302, 351, or even a turbocharged 2.3L four-cylinder. But that’s not the point. The point is that going off the beaten path has its own reward. If you’re all about uniqueness and love a good challenge, the SX V6 or the 255 could be the ultimate conversation starter and a test of your engineering chops.

In the grand tapestry of Ford engine history, the SX V6 and the 255 V8 are undoubtedly footnotes. They were products of their time, the late ’70s and early ’80s, when the rules of the game were changing faster than a pit crew at Daytona. Fuel economy and emissions compliance were the new commandments, and Ford, like everyone else, had to figure out how to satisfy Uncle Sam without boring the driving public to death. Though boring might still be fair. So the next time someone asks you about Ford’s engine lineup for the Bullnose era, you can say, “Sure, everyone knows the 302 and 351, but have you heard about the SX V6 and the 255 V8?” And just like that, you have something to talk about over a cold beverage, leaning on a fender, enjoying the smell of old oil in a garage. It’s shop talk fodder, a piece of history worth remembering, even if it’s just for the chuckle.

So there you go, guys. That’s everything that I know about the Ford SX V6 and the 255 V8. I hope you learned something today. I learned a bunch about these engines doing this video; hope you did too. Uh, if you have any questions, comments, concerns, gripes, internet ramblings, if I got something wrong, drop me a comment below. I appreciate that. And as always, I really appreciate you guys for being here. Thanks again for watching, and we will see you next time. She’s rough around the edges, but she’s doing fine, tinkering away, getting things to shine. No, she’s considered divine. Thanks again for watching. We will see you next time. Thanks again for watching. We will see you next time.