Why no Ecoboost in the F250?

[4570Man]

You'll all tremble when I get my 87 6.2L diesel back on the road. 130HP and just enough torque to pull a doughnut from a paper bag!

My 6.5 turbo diesel is pretty respectable until you hook a trailer on it. Then it falls on its face. My Ford V10 runs laps around it though. The v10 will run laps around my 12v Cummins too. I also have a 24v Cummins that pulls pretty strong.

 

[Renze]

My 6.5 turbo diesel is pretty respectable until you hook a trailer on it. Then it falls on its face. My Ford V10 runs laps around it though. The v10 will run laps around my 12v Cummins too. I also have a 24v Cummins that pulls pretty strong.

At what rpm though ? Are you comfortable towing at 5000rpm ?

I can get used to the torque of my V70 D5. Before i realise it i am in 6th gear at 1500rpm not noticing the high gear because it still responses to the throttle, despite having 2 ton behind it... and still doing 54mpg on the daily commute.

I just dont like gassers for towing, you always need to shift down and make them scream, where with my diesel, torque is available under my right foot in a split second.

Well an automatic might improve that, but it comes at a mileage and a maintenance penalty, the latter i am not willing to take at the mileage i buy used cars...

 

[Renze]

You are really good at your napkin calculations, I'll give you that.
What I am telling you, is that I have measured the cylinder pressures in each of these engines directly myself, with calibrated piezoquartz transducers. Stock the Ecoboost is much lower in stock power level, ~125 bar PCP. But aftermarket calibrations surely push it significantly higher; haven't measured this directly myself but 150 bar is not an unreasonable guess. When the scorpion is running under 165 bar, I would call that close. no?

One thing to keep in mind is that PCP does not work linearly with power/torque, especially when comparing gasoline combustion (peaky) to diesel (more broad, especially with multiple injections to spread it out). So at the same PCP, a diesel engine can be making a higher mean effective pressure (BMEP, = torque).

I looked up my literature, only to realise a lot has changed since the 70s: I was looking at P-V diagrams of the Saab 99 turbo (compression ratio 1:7.5) and the VW rabbit diesel (compression ratio 1:21)

And even though actual measured P-V diagrams differ from the idealised ones that are used to illustrate Otto and Diesel cycles, i believe with the substatially higher compression pressure allowed by turbocharging, and fuel delivery at or near TDC to prevent autocombustion, the pcp might indeed be closer nowadays than i held possible, based on the last P-V diagrams i saw 20 years ago, of direct injection turbo diesels vs port injected gassers of that era...

Nonetheless, multiple diesel injections are not done to spread out combustion, it is killing engine efficiency. For the Tier 2 emission stage, John Deere tried late injection (ignition after the peak compression pressure) to lower the combustion pressure and thereby the formation of NoX. The result was that the engines guzzled fuel, smoked and were unresponsive to the throttle, so that many customers went to Fendt, untill Deere introduced cooled EGR become competitive on fuel consumption again.

There is a pilot injection to get ignition before the main fuel delivery, to lower combustion noise (diesel knock) then 80% is delivered in the main injection, and then an aft injection for emission control. But multiple injections take place around the same few degrees of crankshaft rotation, or sacrifices on efficiency would be too large...

 

[4570Man]

At what rpm though ? Are you comfortable towing at 5000rpm ?

I can get used to the torque of my V70 D5. Before i realise it i am in 6th gear at 1500rpm not noticing the high gear because it still responses to the throttle, despite having 2 ton behind it... and still doing 54mpg on the daily commute.

I just dont like gassers for towing, you always need to shift down and make them scream, where with my diesel, torque is available under my right foot in a split second.

Well an automatic might improve that, but it comes at a mileage and a maintenance penalty, the latter i am not willing to take at the mileage i buy used cars...

The 12 valve only makes 175 hp and 400 fp of toque. I think the 6.5 is rated at 190 hp and still around 400 fp. To make matters worse the 6.5 overheats if you try working it. I’m sure 30 years of gunk in the radiator doesn’t help but they were know from the factory to not cool very well. The V-10 makes peak toque at 3000 rpm. The V10 makes over 2x the HP either one of those diesels do and 20 percent more torque than those diesels do. I would guess that a more period correct 460 gasser or a 454 would pass either one of those diesels. The 6.2 diesels thar started this post were known for good fuel mileage but that’s all they had going. My 6.5 turbo doesn’t even live up to that. It gets 11 mpg in my ton dump truck. The 24 valve Cummins is rated 245 hp 600 fp but mounted in a medium duty truck that’s still pretty depressing power.

 

[Renze]

The 12 valve only makes 175 hp and 400 fp of toque. I think the 6.5 is rated at 190 hp and still around 400 fp. To make matters worse the 6.5 overheats if you try working it. I’m sure 30 years of gunk in the radiator doesn’t help but they were know from the factory to not cool very well. The V-10 makes peak toque at 3000 rpm. The V10 makes over 2x the HP either one of those diesels do and 20 percent more torque than those diesels do. I would guess that a more period correct 460 gasser or a 454 would pass either one of those diesels. The 6.2 diesels thar started this post were known for good fuel mileage but that’s all they had going. My 6.5 turbo doesn’t even live up to that. It gets 11 mpg in my ton dump truck. The 24 valve Cummins is rated 245 hp 600 fp but mounted in a medium duty truck that’s still pretty depressing power.

Ah... youre running a 1st gen at stock trim..
Back in 2005 my uncles 2nd gen 2500 12 valve was tuned to 240-260hp and my nephew was quite happy to race it against any midsized car at the traffic lights, much to the annoyance of my aunt

Anyways, my D5 has steel liners where the 2.4 gas engines are cast-in aliminium liners, in the same open deck block. When you compare the 2.4/2.5 gas versions of 140 and 170hp with my basic 2.4 CR diesel, it will outperform either of them. I chose the 163hp/350Nm version over the 185hp/400nm or 220hp/450nm versions because because i dont need to rip the pavers out of the driveway when i take off, but when comparing a relatively modern engine families diesel and gas versions on the same architecture, the gas engine doesnt come close in performance and drivability if it doesnt have a turbo to get low end power, and acceleration allmost from standstill.

I have full torque from 1750-2200rpm and blast away from 1300rpm onwards, where a gas engine is still climbing rpm before it gives power. And its a 20 year old engine design...

 

[Hay Dude]

Lol. I only bought a gas truck because I couldn't afford a diesel, if I'm being completely honest. My '03 6.0L gas was 13k in great shape, rust free 88k miles. Whereas a dmax would have been closer to 20 for the same condition (back in 2015). I drove a diesel VW for 10 years and loved the heck out of it. Once modded it was as fast as a GTI but with 55mpg.

But then I built a house in the wood and needed a truck. Once I had kids and was glad I didn't need to poison them each time they rode along, too. (well, not poison them quite as much, I suppose).

I'm not trying to defend myself for anything, just offering my perspective as an industry insider who dyno tests prototype engines. Unfortunately we only get access to those engines for which my company (supplier) has been awarded specific business, so I don't get into everything. Just saw that ford has a 6.8L gas V8 coming out shortly... I had no idea, since we have no powertrain parts in it, apparently. Should be a nice upgrade from the 6.2

Ummmm, okaaaay.

 

[Hay Dude]

My 6.5 turbo diesel is pretty respectable until you hook a trailer on it. Then it falls on its face. My Ford V10 runs laps around it though. The v10 will run laps around my 12v Cummins too. I also have a 24v Cummins that pulls pretty strong.

Here we go again, comparing modern gas engines to ancient relic diesels from 35 years ago…..

I had a 1991 F-350 with a 460 gasser in it. It made 220 HP.
What a pile of
Drank gas and low power.

 

[Hay Dude]

The 12 valve only makes 175 hp and 400 fp of toque. I think the 6.5 is rated at 190 hp and still around 400 fp. To make matters worse the 6.5 overheats if you try working it. I’m sure 30 years of gunk in the radiator doesn’t help but they were know from the factory to not cool very well. The V-10 makes peak toque at 3000 rpm. The V10 makes over 2x the HP either one of those diesels do and 20 percent more torque than those diesels do. I would guess that a more period correct 460 gasser or a 454 would pass either one of those diesels. The 6.2 diesels thar started this post were known for good fuel mileage but that’s all they had going. My 6.5 turbo doesn’t even live up to that. It gets 11 mpg in my ton dump truck. The 24 valve Cummins is rated 245 hp 600 fp but mounted in a medium duty truck that’s still pretty depressing power.

See, there’s your problem, you don’t own a modern diesel in a light truck. If you did, your diesel v. gas analysis posts wouldn’t be dismal.
If you took a ride in mine, especially towing heavy, you’d run out an buy one.
Went across scales yesterday @ 49,920lbs!

 

[deezler]

Ummmm, okaaaay.

For any diesel before DPFs, you know it's true. The DPF cost diesel engines substantial efficiency but it was very necessary to drastically lower the PM (particulate matter) emissions.

Cold start at idle, a gas engine heats up the cats super fast and is relatively clean. Cold start an older diesel, and you're spewing massive PM into the air around your driveway, garage, house, etc. The unthrottled diesel engine has 10 times the exhaust flow at idle. Loading your tykes in and out of car seats all winter long? It's a huge exposure to emissions.

 

[MechanicalGuy]

Yeah the ecoboost i drove didn't scream at all. It was stout.