Ultimate 7.3 Godzilla Engine Guide

Though it was released in 2020, Ford’s 7.3 Godzilla engine hearkens back to an earlier and simpler time. A time when big-block V8s with pushrods used to terrorize the roads and rip up the blacktop. This was before the days of direct injection and twin-scroll turbochargers being stuffed inside of small-displacement inline-fours and V6s. It was when power and simplicity were at their peak, and engines were judged on their roar instead of gas mileage.

The Ford 7.3 Godzilla V8 brings all of that back and more, with its massive 455 cubic inches of naturally aspirated displacement. Ford has primarily used it inside of their Super Duty and commercial vehicles, but they have also made it available as a crate engine for those looking to use it as part of a swap. Ford designed the engine to produce massive amounts of low-end torque, making it perfect for towing virtually anything you need. Yet, it’s also incredibly compact for its displacement and output, making it very easy to work on and do maintenance. 

In addition to the gasoline powered 7.3 Godzilla engines, there are also versions that can run on propane and liquefied petroleum gas (LPG), as well as compressed natural gas (CNG). Most gasoline versions are also flex-fuel, meaning they can use ethanol or E85, too. 

Ford 7.3 Godzilla Engine History

Ford first released the 7.3 Godzilla engine for the 2020 model year. It is the successor to the slightly smaller 6.2 Boss V8 and 6.8 Triton V10, though it is very different. Both the Boss and Triton engines belong to Ford’s modular engine family, but the Godzilla stands alone as a unique design. Instead of using the modular block with a dual overhead camshaft (DOHC) valve train, Ford engineers opted instead to use a new single in-block camshaft and overhead valve (OHV) train. 

The reason behind this according to Ford engineers is pretty simple: Low-end torque, simplicity, and – surprisingly enough – fuel economy. They designed the engine to be used mainly in vehicles that are above a 8,500 pound gross vehicle weight rating (GVWR) and that handle extensive towing. Depending on the model, it makes between 300–430 horsepower and 425–475 lb-ft of torque.

While most DOHC setups excel in the mid and upper-RPM ranges, OHV pushrod configurations are great at building torque at low-RPM. This is exactly what you need when towing, and it also helps with fuel economy. When you can make peak power at a lower-RPM you use less gas, so the larger displacement actually helps you save at the pump. While it wouldn’t work in a smaller vehicle, say an F-150 or lighter SUV, it works perfectly in Ford’s Super Duty and commercial vehicles that tow often. 

In addition, the OHV setup is much less complicated than a DOHC one, not least of which is because it only has one camshaft instead of four. That also helps keep the engine compact, as it’s actually shorter than the 6.8 V10 Triton it replaced. The Godzilla has variable valve timing for performance and fuel economy, and was designed with a race car heritage in mind. 

The Alternative Fuel Godzillas

In addition to the standard gasoline powered 7.3 Godzilla engines, there are several versions that run on alternative fuels. It’s also worth noting that many of the gasoline powered versions can run on E85 flex-fuel, too. There are also different power options available for the Godzilla, depending on what you need your truck or van to deliver.

For the E-Series and medium duty trucks (F-600 or larger), you can have your choice of either the economy tune or the premium tune. The economy tune makes 300 horsepower and 425 lb-ft of torque, while the premium tune makes 350 horsepower and 468 lb-ft of torque. The economy tunes are meant for those who are not towing as much and want improved gas mileage.

There are also several alternative fuel versions of the Godzilla that have been created by aftermarket companies partly in-conjunction with Ford. Roush offers their “Roush CleanTech” alternative fuel solution which allows the Godzilla to be run on propane, also known as propane autogas or liquefied petroleum gas (LPG). This is available on the E/F-450, F-550, F-650, F-750, as well as on the F-53 and F-59 motorhome stripped chassis. 

You can also purchase the medium duty and larger Fords with a fuel system that can run on compressed natural gas (CNG). Additionally, Landi Renzo USA created a fuel system for the Godzilla that uses CNG, too. Landi Renzo’s CNG fuel system is available for the same models as the Roush CleanTech. 

Using alternative fuels reduces emissions and boosts fuel economy, and does not lead to any drop in horsepower or torque. In some cases it can actually increase it. 

Ford 7.3 Godzilla Specs

Engine Name	7.3 Godzilla
Engine Family	Ford Godzilla V8
Model Years	2020-Present
Displacement	7.3 liters (445 cid)
Aspiration	Naturally Aspirated
Configuration	90° V8
Compression Ratio	10.5:1
Bore and Stroke	4.22″ x 9.976″ (107.2mm x 101mm)
Valve Train	OHV, 2 valve/cylinder, 16V total
Fuel System	Electronic Fuel Injection
Fuel Type	Gasoline, Propane/LPG, CNG
Head Material	Aluminum
Block Material	Cast Iron
Horsepower Output	300-430 horsepower
Torque Output	425–475 lb-ft of torque

Vehicle Applications

• 2020–Present Ford Super Duty F-250/350/450/550/600
• 2020–Present Ford Medium Duty F-650/750
• 2020–Present Ford F-53 Motorhome Stripped Chassis
• 2020–Present Ford F-59 Commercial Stripped Chassis
• 2021–Present Ford E-350/450
• 2022–Present Blue Bird Vision school bus

Ford 7.3 Godzilla Engine Design Basics

The Godzilla engine has 7.3 liters (445 cid) of total displacement and has a 90° V8 configuration. The bore and stroke is 4.22″ x 9.976″ (107.2 mm x 101 mm), and the block can be bored and honed to a max displacement of nearly ~8.1 liters (~500 cid). Ford manufactures the cylinder heads from aluminum and the cylinder block from cast iron. The block itself has deep-skirt and siamesed cylinders, with four cross-bolted main bearings. It shares the bell housing pattern with the 4.6/5.0/5.4 modular engines. 

The pistons are made from hypereutectic aluminum, the connecting rods are powdered metal I-Beam, and the crankshaft is forged steel.  Ford made the combustion chambers wedge-shaped and specifically designed them for efficiency, with the spark plug located at the center of the dish. The pistons have oil-squirters to cool them, which helps them avoid detonation under high-load and improves longevity. Oil pressure is kept with a variable-displacement oil pump. The pump can change pressure on the fly depending on the driving situation, helping reduce parasitic losses.

Valve Train and Fueling

The aluminum heads have tall ports for the best flow and charge-air motion. The valve train is an overhead valve (OHV) pushrod setup with two valves/per cylinder (16 valve total) and a single in-block camshaft. The Godzilla uses forged aluminum rocker arms with a die-cast, roller fulcrum, and very tall Beehive valve springs. The lifters are hydraulic rollers with plastic holders, and there are nine cam journals of 60 mm each. 

The system uses a single timing chain with two separate tensioners. The camshaft has durations of 201°/212° (intake/exhaust @0.050”), lifts of 0.539”/0.595”, and uses variable valve timing (VVT) for performance and fuel economy. Compression runs at a static 10.5:1 on all versions.

Fuel is supplied via sequential multi-point electronic port injection. The throttle body is 80 mm, and the Godzilla uses a drive-by-wire electronic throttle control setup. In addition to running on 87 octane, most gasoline powered Godzillas can also use ethanol or E85 instead, thanks to a flex-fuel system. 

Ford offers the use of air brakes and other air systems (suspension, horn, etc) with the Godzilla. Previously it was only available on their diesel offerings, but Ford added an engine driven air compressor to expand availability to the non-diesel Godzilla.

The Alternative Fuel Godzillas Explained

As we mentioned earlier, there are a few alternative fuel systems that have been designed for the 7.3 Godzilla. First up is the Roush CleanTech system. CleanTech is a propane (also known as propane autogas or liquefied petroleum gas – LPG) fuel system that meets CARB requirements for low nitrogen-oxide emissions. It uses a Gen 5 system with forged fuel rails. Roush first brought out CleanTech in 2010, and has installed it on more than 40,000 vehicles so far.

Additionally, there is also the Landi Renzo USA compressed natural gas (CNG) fuel system for the 7.3 Godzilla. It is mainly designed for commercial vehicles, like those used at airports and hotels, as well as delivery and package trucks. It is EPA and CARB certified, and maintains the Ford warranty if installed. 

Ford also has an option to order the Godzilla to run on natural gas for the F-600 series and larger. In order to facilitate the natural gas fuel system, the valve train is upgraded and strengthened to withstand the higher temperatures. 

7.3 Godzilla Common Problems and Reliability

Considering Ford just released the 7.3 Godzilla engine for the 2020 model year, it is still practically brand new by production standards. Thus, it can be a bit hard to determine just how reliable the engine is. However, the limited data so far points to the Godzilla being a reliable and sturdy engine. 

The Godzilla is widely used by fleets and companies in commercial vehicles. So even within just a few years there are already some with considerable amounts of mileage. For the most part, they have emerged as being capable of taking a serious beating and quite capable of long-distance towing.

The only issue that has crept up for some owners is spark plug wiring harness failure. Previously, we covered the issue in our 7.3 Godzilla’s reliability on our partner site, Diesel IQ. The wiring harness connects the spark plug to the ignition coil, so it’s very important. Faulty harnesses can result in cylinder misfires and detonation. Ford acknowledged the issue was present and ended up rectifying it, making it a non-issue on all new Godzillas. 

Besides that, the Godzilla has so far proven to be a very reliable motor. We fully expect it to be able to reach more than 300,000 miles without needing a full rebuild. 

Ford 7.3 Godzilla Performance and Upgrades

Now let’s talk about the most exciting part of the 7.3 Godzilla: Performance. Depending on the model, the Godzilla produces 300–430 horsepower and 425–475 lb-ft of torque. The most powerful versions are inside of the Super Dutys, rated at 430 horsepower and 475 lb-ft of torque. The crate engines are rated the same. The Godzilla is capable of towing an astounding 37,000 pounds inside the F-750.

However, considering the Godzilla has a whopping 7.3 liters of displacement, there is still lots of room to make even more power. Incredibly, the 7.3 Godzilla has been shown to be capable of making more than 750 horsepower on pump gas while staying naturally aspirated. With the right blower, the Godzilla is easily capable of more than 1,000 horsepower. 

What’s more, even though it is 7.3 liters the Godzilla is surprisingly compact, making it ideal for swaps. It’s smaller than Ford’s smaller 5.0 Coyote power plant from their modular engine family. You can even fit the Godzilla inside a Foxbody-era Mustang if you really wanted to. It is much heavier however, weighing roughly 130 pounds more than the Coyote, largely due to the cast iron block. 

Top Engine Mods

If you are just doing a moderate Godzilla build, say if you’re just looking to get some extra horsepower and torque for some better passing ability and towing capacity, there are a few simple mods you can add. The two hands down best mods for moderate 7.3 Godzilla builds are going to be long-tube headers and tuning. As YouTuber ReVan Evan showed, with just headers, tuning, and high octane fuel, the Godzilla put out more than 500 horsepower and 500 lb-ft of torque. 

The next step up is adding a higher lift and more aggressive camshaft, as well as looking at a new intake manifold. Adding the camshaft put the Godzilla up more than 50 horsepower and 25 lb-ft of torque compared to just headers and tuning. If that isn’t enough, with a new billet intake manifold, new lifters, more aggressive cam, and titanium valves, the Godzilla made 790 horsepower naturally aspirated. And that is with the stock block and heads. 

From there, adding a blower or turbocharger can give you all of the power you could ever want. With 790 crank horsepower, even a small blower will push it past 1,000 horsepower without even breaking a sweat. 

Ford 7.3 Godzilla Engine Summary

So far the Ford 7.3 Godzilla has proven to be a solid and dependable engine during its short production span. Ford just introduced it for 2020, so it’s barely been on the market for a couple of years. Still, Ford is only expanding production of the Godzilla engine line, and using it extensively inside of commercial vehicles and even school buses. 

The beauty of the Ford  7.3 Godzilla is in its simplicity. A cast iron block, overhead valve train with pushrods, and a single in-block camshaft, the 7.3 Godzilla is almost from another century. Yet, it has shown to fit right in with the times, proving its worth as an incredible tank of a towing machine. Performance wise it is no slouch, making 430 horsepower and 475 lb-ft of torque in its more powerful iteration.

Ford shows no signs of slowing down the 7.3 Godzilla, and it seems poised to only become more widely used in the future. Let us know your experiences with the 7.3 Godzilla in the comments below!