Home Forums Gear Hunting Trucks and Four-Wheel Drives Ford's New 7.3 Gas Engine Details

Back in February we outlined the broad strokes of the new gas big-block V-8 and in-house-designed Power Stroke turbodiesel V-8 that will power Ford's heavy duty and commercial trucks for 2020. Now we have lots more details to fill in.

As a reminder, the new 7.3-liter gasser slims down enough to fit in all of Ford's motorhome and cube-van chassis-cab applications by ditching two overhead cams in favor of a single cam snuggled deep in the block—a technology that's been absent from Ford's Super Duty truck lineup since the overhead-cam "Modular" engines replaced the "385" family of pushrod big blocks in 1997. (Note—it does not easily fit in any Ford cars.) And it mounts to a beefier new 10-speed transmission with new features.

BEST IN CLASS GAS-ENGINE POWER/TORQUE
As an option in its 2020 F-250 and F-350 trucks, Ford's new 7.3-liter V-8—that's the largest displacement in the class—will crank out 430 hp at 5,500 rpm and 475 lb-ft at 4,000 rpm. That shades GM's 6.6-liter V-8 by 29 hp and 11 lb-ft and Ram's 6.4-liter Hemi by 20 hp and 46 lb-ft. Note that the 7.3 replaces the 288-hp/424-lb-ft 6.8-liter V-10, while Ford's SOHC 6.2-liter V-8 still serves as the base engine in the F-250 and F-350, producing 385 hp at 5,750 rpm and 430 lb-ft of torque at 3,800 rpm. The 7.3-liter will be standard on the 2021 F-550, F-600, F-650 and F-750 Medium Duty trucks and E-Series, as well as F-53 and F-59 stripped chassis, and in many of these applications rated at 8,500-plus pounds gross vehicle weight, engines are rated for continuous power and the useful rev range is much lower. In most of these applications, the engine is rated at 468 lb-ft at 3,900 rpm, with horsepower limited across the rev range to the 350 hp it makes at the torque peak.

BUILT TO LAST INDEFINITELY
The 7.3-liter's forged steel crankshaft features oversized main and rod bearings, and it's fixed to the block with four vertical and two horizontal cross bolts. Many of the materials in use are upgraded to turbo-engine specifications. The roller bearings on the valve tappets are carbon-nitrided, piston-cooling oil jets are employed, the valvetrain is fed much higher rates of oil flow, and the variable-displacement oil pump is designed to be able to increase oil flow to maintain pressure as bearings wear or when viscosity drops at very high temperatures. The wear evident on an engine dismantled for our viewing after 3,200 hours of max-output running (that's 133 days of 24/7 flogging) is apparently so minimal that it's difficult to extrapolate a projected failure mileage.

These new one-piece forged steel pistons are far shorter in height than the second-gen Power Stroke's aluminum pistons, and they drop the compression ratio from 16.2:1 to 15.8:1. They feature much tighter ring lands and what are claimed to be the lowest-tension rings in the industry (for lowest-in-class friction). The piston pins are smaller than usual, and the connecting rod bearings they run in feature bronze inserts. The mass of the new steel pistons is only slightly greater than the aluminum ones they replace. New split-stream oil-cooling jets target both the piston crown and those new smaller piston pins.

I was expecting better numbers. It barely beat what is out there right now.

That was my initial thought as well but then I saw the torque curve on the 7.3. Based on the details of the construction it was clearly designed for longevity not raw power output.

This is the feeling I get from it too. It was designed to give long lasting service in dump trucks, bucket trucks, and other industrial rigs. I’m actually surprised they’re putting it in the 250 and 350s but I guess they’re probably doing that to get production numbers up to pay for development.

And 400ftlb of torque at only 1500rpm is pretty impressive to me. That’s diesel numbers from a decade or so ago and guys are still going nuts over the the old rigs with 7.3s and 5.9s that we’re showing those numbers. I’m thinking coupled with the 10sp this thing will pull like crazy. The only question is will it drink fuel like crazy. Ford says it won’t but they aren’t going to advertise anything as being good for 8mpg, real miles on the road will be the true test I guess.

The new 10-speed TorqShift automatic transmission is available across the range, with the six-speed automatic serving as the base transmission. Ford says the 10-speed “features a wider gear ratio span than the 6-speed and is designed for the harshest towing conditions.” The 10-speed also has selectable drive modes with normal, tow/haul, eco, slippery, and deep sand and snow modes.

No it’s a revamped for high torque version of the 10 speed in the Raptor.

Thanks for the info on the tranny. I work in an allison reman shop and rumors were Ford and Toyota were gonna use the new 10 speed. We knew Chevy would stick with it.

Ford has chosen to call this engine platform: "Godzilla". I like it:-).