The 5.4L 3v had issues with the phasers, yes. The 6.8L 3v engine did not have phasers; IIRC this is because part of the system needed space which was already occupied by the balance shaft in the head, unique to the v-10.

 

I fully expect the 7.3L will be as efficient as the 6.2L while delivering better HP and Torque numbers. Fuel efficiency is important to folks. I understand that folks who have HD pickups know and accept the fact these behemoths will not, never will, and physically can never get the mileage of a Toyota Prius.

However, within the HD pickup world, relative gas mileage is important. That why there are so many threads on the MPG penalty of the 4.30 gears viz a viz the 3.73 gear.

If the 7.3L delivers worse MPG mileage than the 6.2L unloaded, then the 6.2L is in for a continued long run. If the 7.3L only advantage is higher HP and Torque at reasonable MPG and only when loaded, then the 7.3L will be only be used in Class MH chassis which by definition is "always loaded', and for fleet applications where the trucks are made with special heavy weight bodies such as ambulances, or service trucks, or for those who only use their trucks as a tug for huge 5'vers. The normal guy who tows no more than 1/2 the time will stick to the 6.2L, and then be concerned whether to get the 3.73 or 4.30 rear.

 

Actually, it wasn't space. the problem was the balance shaft was driven off the right cam. Advance or retard the cam and you throw the balance off!

 

You're describing the situation that has existed in the heavy duty pickup segment for decades.

Fuel economy has always mattered, and was a consideration in the 1999 Super Duty which got the first modular engines, along with the redesign in 2005 which saw the 3V heads introduced. The 2011 – 2019 Super Duties with the first in decades to only have a single gasoline engine option. In all of the other years, the larger engine was a tradeoff for capability against fuel economy. People still happily purchased the larger engines, and dealt with the reduced fuel economy as a result. The V-10 was put into a substantial amount of pickups despite the terrible fuel economy, and was never relegated to commercial/RV use. Why would this be different?

Physics still apply. Pumping losses, internal frictional losses, and combustion efficiency are still largely immovable objects in the engine design world. What has so drastically changed with engine technology since 2011 to make this the revolutionary engine that gets that much larger, more powerful, and more efficient at the same time? To my knowledge this has never been done.

Of course we're just spitballing here, we will all find out when the trucks hit the road. It's an interesting conversation, though.

 

no new inventions.. for internal combustion engines... little changes... small advances...
electronic controls
roller valve trains..
variable valve timing.
better oils

no variable displacement for working trucks.. YET.

moving real Weight will always have limits... towing or hauling.

must feed them horses.... going to LEAN.. = misfires.,, not better mpg...
a few years back.. Nissan.. made a ceramic engine block..
trying to control the Thermo heat issues in hard working engines..
no test results were made available.

 

there were rumors the 7.3 was going to have a compacted graphite iron CGI block

 

You bring up good points and I understand what you are saying. When the V10 replaced the 460 it was more powerful and more efficient. Was that because it was 45 cubes smaller or simply a better design?

One thing to note is most people with the 2V V10 get better mpg than the 3V. I personally experienced this. The 3V was a step up in technology and power but not necessarily in efficiency.

I am betting they have really optimized the heads. They look different to me from anything else. And the exhaust manifolds look super good. When combined with the new 10 speed there is a chance it has better drive train efficiency.

We will see eventually but even if it gets mpg like my V10 but has quite a bit more power, not to mention less complexity, I would buy it.

 

I think this is likely what we will see. My comments were with respect to the existing 6.2L engine, which is less than a decade old. The V-10 is smaller, but the architecture dates back to the early 1990s.

Every thread on gearing that I've ever seen on FTE always ends up with the overwhelming majority insisting the 4.30 gears of the only way to go. Despite the penalty in efficiency, people seem to think the added power is worthwhile for what they do with their trucks. I think that will be the tradeoff people make when choosing the 7.3 against the 6.2. Most of the recreational/enthusiast market will spend the money for the more powerful engine regardless of a slight decrease in efficiency. I know I certainly would.

 

towing heavy ( over 8k pounds ).. the transmission will still be near 1 to 1.... as long ago...

I still vote for a 2 speed rear end... 3.55 and 4.30..
I drove a truck for a few years.. I like the air shifted 2 speed rear end ....

 

I had a 6.8 3V 3.73 truck and replaced it with a truck with 4.30s. I liked it much better with 4.30s and the fuel mileage difference was insignificant. Both averaged 105-11 MPG depending on the season. The 4.30 truck was better towing, both power and MPG. It was also better around town in stop and go traffic. Running empty at highway speeds was the only time the 3.73 truck was slightly better.

 

It seems to me that with a 10 speed transmission the rear axle ratio is less of an issue except for accelerating off the line in 1st gear. After that you should be able to keep the engine in the power band due to the closer gear spacing.

 

 

 

Have the horsepower/torque numbers for the 7.3L been released yet?? My boss told me he'd seen something in a release about the F-600 but I can't find it.

 

prolly a few more months