Have you heard the rumor claiming Ford plans to jam its 7.3L Godzilla V8 in the back of the Ford GT as a final sendoff? On the surface, sure, the idea sounds cool, but in practice, it’s a downright impossibility. Especially if you think about the program holistically–both as a business entity that needs to make money, and mechanically as a collection of pieces that need to fit together.
The basis for this rumor is a summer sighting of a Ford GT development mule near an EPA testing facility outside Detroit. The mule was spotted with elongated exhaust tips protruding well past the GT’s rear fascia. The rear valence and diffuser are also missing, offering a glimpse of the transaxle cradle and parts of the exhaust, including the catalytic converters. Onlookers and sources have claimed the Ford GT in question sounded like no other GT out there, lending fuel to the V8 rumor fire. We’ll touch on why that Ford GT in particular sounded different in a moment.
First thing’s first. The Ford GT was designed around the 3.5L EcoBoost V6. Ford will tell you that, Multimatic will tell you that, and it’s abundantly clear if you’ve seen as many of them with the skin off, as I have. The engine is bolted directly to the bottom of the tub, before the Z frame structure that surrounds the engine and supports the transmission and rear suspension is introduced. From a tub perspective, if a new engine was to be introduced the engine mounts would need redesigning, and the fuel tank bulkhead would need to be re-profiled, at the bare minimum.
Sure, OHV engines benefit from being more compact than DOHC engines, but that benefit only applies to the height and width of the engine. Otherwise, a V8 is fundamentally longer than a V6, no matter where you put the camshaft.
If you don’t believe me just tally the bore diameters for one bank if you’re looking for a rough idea of the difference in length. The 3.5L EcoBoost V6 has a 92.5 mm bore diameter, equalling 277.5 mm when multiplied by three. The short-stroke 7.3L Godzilla V8 has 107.2 mm bore diameters, which when multiplied by four equals 428.8 mm.
The 151.3 mm difference only pertains to the diameters of the cylinders without accounting for cylinder walls or block thickness, but it illustrates the salient point. Even if Ford wanted to put a cast-iron truck motor in its flagship supercar, the 7.3L Godzilla V8 is too long.
An increase in engine length would contribute to several issues. The intake manifold would run into the K-frame brace which would require pushing the support further back, necessitating relocation of the oil tank. More significantly, there would likely be clearance issues with the pushrod suspension levers and DSSV dampers which live on either side of the oil tank. Below deck, the transaxle cradle would need to be redesigned or moved. Basically, we’re talking about significant changes to the rear structure of the GT and its accompanying bodywork.
The cost of engineering talent, validation, and tooling, among other things, is prohibitively expensive to be a realistic avenue for a low-volume program that will only exist for a further 12 months. That’s before we even talk about the weight balance dynamic issues that would manifest from jamming a 580-pound cast-iron boat anchor in the back.
Circling back to the V8 Ford GT rumors, the spy shots from July show the transaxle cradle in the exact same location, with the only discernible difference being the exhaust aft of the cats. While difficult to tell for certain, it looks quite similar to the titanium unit currently employed, with obvious differences to the center exit pipes.
The smoking gun is claimed to be the dry-sump reservoir’s oil cap that looks to be in a different location. But it’s not. The low angle of the spy shots simply makes the oil cap visible through the large air extraction gap that lay between the Lexan engine cover and the rest of the hatch that extends rearward to cover the internal storage cubby.
Instead of a V8 Ford GT, it’s more likely Ford and Multimatic are working to integrate Mk II GT parts to the road car, as the two already share a significant amount of content. Other mules have been spotted wearing the Mk II’s massive air intake in place of the road car’s engine cover.
If you’ve ever had the privilege to hear one of the Mk II GT’s idle, run the dyno, or scream down the straightaway you’ll know they sound absolutely nothing like the road-going version of the supercar. The sound is downright guttural with a splash of bass, it would be easy to confuse the sound for something else.
Believe me, I’ve had my brain rattled more than a few times by the sound of a Ford GT Mk II being put through multiple dyno runs, as engineers worked to dial in the final mapping parameters.
There have been other rumors circulating that the team is looking to push the road car towards the Mk II’s 700 hp figure as part of the GT’s farewell. The Ford GT has already gone through multiple powertrain evolutions since 2017 en route to its current 660 hp figure. The intercoolers were revised, the exhaust was changed ahead of 2019, and the intake plenums were optimized for the 2020 model year. All of those changes required re-homologation, including a visit to the EPA.
This is a car that won Le Mans, this is a car that was designed around the powertrain it currently employs. Do you really think Ford and Multimatic will invest valuable time and resources into making the car worse? I don’t.