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Old 09-29-2020, 05:55 PM   #1
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New Ford 6.8L

Ok, it’s not the return of the V10 — that’s plenty dead. However, after union negotiations with Ford, Jerry Dias disclosed in Q&A session with press that Ford will be building a new 6.8L engine at the Windsor plant.

Dias also stated the new engine would go into derivatives of Mustang and F-150 pickups. That essentially narrows it down to a gasoline V8.


In somewhat related news, Ford just announced 2021 F-150s with upgraded 5.0L V8 will now have 400 HP at 6,000 RPM 410 lb-ft at 4,250 RPM, with a maximum towing capacity of 13,000 pounds. That’s quite a bit for a 1/2-ton pickup; although high RPM and trucks generally don’t go well together.

Since F-150 with Eco-Boost V6 goes as high as 14,000 pounds of towing, I’m wondering if the 6.8L V8 will be aimed at fun factor (like limited-production Raptor pickup) or more work oriented (increasing un-boosted tow rating). Maybe both?

No detail information on engine was disclosed, but many feel it’s a lower-displacement version of 7.3L V8, perhaps/likely with aluminum block. But who knows, could be entirely different.
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Old 09-29-2020, 06:51 PM   #2
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I'm guessing that it's just for the "fun factor"!
They've got lots of engines for workhorse duty...
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Old 09-29-2020, 08:35 PM   #3
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Too bad Ford, and the others, don't post the payloads of those trucks along with that useless gigantic max tow weight. They'll all be short on payload looonnng before to they tow that max weight in a rv.
A 1/2 ton V6, or any motor, with 14000lb TT with a tongue weight of 1800+lbs (13%) before anything else is added or 5th wheel at 3000+lbs (22%) pin weight , hope I'm not driving next to them.
That max tow weight for trucks & the rv manufacturers posting useless dry weights do nothing but confuse newbies coming into the towable RV lifestyle.
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Old 09-29-2020, 09:19 PM   #4
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Originally Posted by Travelin' Texans View Post
Too bad Ford, and the others, don't post the payloads of those trucks along with that useless gigantic max tow weight. They'll all be short on payload looonnng before to they tow that max weight in a rv.
A 1/2 ton V6, or any motor, with 14000lb TT with a tongue weight of 1800+lbs (13%) before anything else is added or 5th wheel at 3000+lbs (22%) pin weight , hope I'm not driving next to them.
That max tow weight for trucks & the rv manufacturers posting useless dry weights do nothing but confuse newbies coming into the towable RV lifestyle.
Attachment 26386

Yeah, it can be a problem. At least one RAM 1/2-ton has low GVWR (and therefore payload) that limits towing significantly. Rear axle rating is less than ideal. It’s great for cruising but can’t tow much.

Anyway, the following maximum ratings for some F-150’s aren’t that bad by comparison to some other 1/2-ton pickups I’ve seen. I’m not in market for a pickup, but would go with 5.0L V8 if I was.
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Old 09-29-2020, 11:53 PM   #5
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The V10 has got to go. It has no b@lls and RV applications needs more torque. I hope they start building the cut-away with the 7.3L. Then, I may stay with Ford.
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Old 09-30-2020, 12:59 AM   #6
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The V10 has got to go. It has no b@lls and RV applications needs more torque. I hope they start building the cut-away with the 7.3L. Then, I may stay with Ford.

That’s already happened. Ford switched from the 6.8L V10 to 7.3L V8 last year on the larger E-Series Cutaways. The smaller Transit Cutaways presently get 3.5L V6, either naturally aspirated or turbocharged. There’s not much “engine” middle ground in Ford Cutaways.


My initial “guess” is that the new 6.8L V8 will probably be an aluminum-block engine to keep weight down for F-150 and particularly the Mustang. If based on 7.3L Godzilla V8, it would likely require smaller cylinder bores to increase thickness between cylinders. That “could” explain displacement reduction from 7.3 to 6.8.

Anyway, in my opinion the 7.3L is a bit too large for smaller Class Cs built on E-350 to achieve optimum fuel economy. In time maybe a 6.8L V8 will find its way into E-Series but I wouldn’t expect it. Still, for motorhomes getting 10+ MPG on the highway, a smaller engine should help a little. Problem is that it’s only about 7% smaller which isn’t much.

Accuracy of my guesses on 7.3L V8 were dismal, so these are probably off too.
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Old 09-30-2020, 01:13 AM   #7
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I'm guessing that it's just for the "fun factor"!
They've got lots of engines for workhorse duty...

Going by numbers alone, a 400 HP 3.5L V6 EcoBoost with 500 lb-ft of torque could power any large truck or motorhome. But it wouldn’t last in severe truck duty.

Not counting the expensive PowerStroke diesel, Ford mainly has the 7.3L gas V8 as a “workhorse”. Are you thinking of others?
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Old 09-30-2020, 01:23 AM   #8
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I personally think that Ford's diesel and gas heavy duty engines do a pretty darn good job. I just think that this new engine will not be targeting the HD market.
It might work well in the half-ton trucks, and it would be awesome in a Mach One.
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Old 09-30-2020, 02:08 AM   #9
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Originally Posted by Chance View Post
That’s already happened. Ford switched from the 6.8L V10 to 7.3L V8 last year on the larger E-Series Cutaways. The smaller Transit Cutaways presently get 3.5L V6, either naturally aspirated or turbocharged. There’s not much “engine” middle ground in Ford Cutaways.


My initial “guess” is that the new 6.8L V8 will probably be an aluminum-block engine to keep weight down for F-150 and particularly the Mustang. If based on 7.3L Godzilla V8, it would likely require smaller cylinder bores to increase thickness between cylinders. That “could” explain displacement reduction from 7.3 to 6.8.

Anyway, in my opinion the 7.3L is a bit too large for smaller Class Cs built on E-350 to achieve optimum fuel economy. In time maybe a 6.8L V8 will find its way into E-Series but I wouldn’t expect it. Still, for motorhomes getting 10+ MPG on the highway, a smaller engine should help a little. Problem is that it’s only about 7% smaller which isn’t much.

Accuracy of my guesses on 7.3L V8 were dismal, so these are probably off too.
To the last sentence, no worries. I like your posts.

Aluminum will (and should) getter a smaller bore because it's harder to dissipate the heat. Heat transfer happens quicker in an aluminum block where steel retains the heat within the cylinder and heat transfer is slower, allowing the coolant ports to work their magic but increase the wear on pistons, rings and oil. Smaller bores in aluminum sort of have the same effect - keeping the cylinder walls cool (relatively) and engine light weight.

You can reduce both scenarios with a larger radiator and the right thermostat, but that's a trade off as well. More metal and more water.

The aluminum trade-off may be curb weight, GVWR and GCWR, which goes up. If it doesn't become a zero sum game, they can use a sturdier frame and increase the payload but not the GCWR because the increased frame weight will take it's toll. Much like 4WD vehicles. Add a font drive train and it increases weight, reducing towing capacity over a 2WD of the model.

I like the what they did with the eco-boost in the GT40. Hell of a lot of horsepower but not too much need for torque. Change up the rear axle ratio and do a little ECM programming and you might have a motor that'll carry a 24klb motorhome down the road at decent performance and gas mileage.

Just thinking on my part. Keep well.
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Old 09-30-2020, 02:13 AM   #10
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Originally Posted by Bob Denman View Post
I personally think that Ford's diesel and gas heavy duty engines do a pretty darn good job. I just think that this new engine will not be targeting the HD market.
It might work well in the half-ton trucks, and it would be awesome in a Mach One.
The only problem with torque is wheel spin coming off the line. You have to top-line the the cam and induction system to come off the line clean and bring in the horsepower after the 300ft mark. Tough game to get right.
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Old 09-30-2020, 11:00 AM   #11
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Traction control software takes care of the wheelspin, and allows anyone to get the most out of the available traction...

... and there are no trade-offs in this approach: unlike when gearing is used to accomplish the task.
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Old 09-30-2020, 04:17 PM   #12
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.....cut....

Aluminum will (and should) getter a smaller bore because it's harder to dissipate the heat. Heat transfer happens quicker in an aluminum block where steel retains the heat within the cylinder and heat transfer is slower, allowing the coolant ports to work their magic but increase the wear on pistons, rings and oil. Smaller bores in aluminum sort of have the same effect - keeping the cylinder walls cool (relatively) and engine light weight.

.....cut.....

I was referring to structural strength and stiffness of aluminum versus cast iron blocks, not heat transfer.
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Old 09-30-2020, 04:22 PM   #13
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The real question for me is what will this new engine be based on? Will it be high-tech like the 5.0L V8 in F-150 and Mustang, or low-tech based on OHV pushrod design to keep size, weight, and cost lower?

Most opinions assume a smaller version of the “low-tech” 7.3L OHV V8, but who’s to say Ford won’t upgrade the existing 6.2L V8 in displacement to 6.8L and install DOHC heads to create a larger version of the Coyote 5.0?

A modern 6.8L DOHC V8 could make over 500 HP and 550 lb-ft in pick-up tune, and even more in Mustang tune, which would exceed EcoBoost ratings. However, its large physical size makes this unlikely in my opinion.

On the other hand, Ford may be able to get 500 HP out of an OHV 6.8L low-tech V8 at lower cost than an EcoBoost V6.

I’m interested to see actual engine details.
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Old 09-30-2020, 04:54 PM   #14
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A Coyote 6.8 would sure be nice...
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Old 09-30-2020, 06:55 PM   #15
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A Coyote 6.8 would sure be nice...
The Aluminator XS 5.2L 4V DOHC Crate Engine is a lot more powerful and available as a crate engine. Nothing sounds as good as a V-8 with a flat plane crank @ 8,000 rpm
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Old 09-30-2020, 08:20 PM   #16
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It’s interesting that even in pickup tune, the 2021 Ford F-150’s 5.0L V8 can make more power at same RPM than the Ford 6.8L V10 in Class Cs and Axis/Vegas. Granted, power ratings may be on different basis.

5.0L V8 = 410 lb-ft at 4,250 RPM = 332 HP.

That beats the V10’s maximum of 305 HP at same 4,250 RPM.

The V10 only produces 377 lb-ft at 4,250 RPM.

If Ford upgraded 5.0L V8 to iron block for durability, I could see it making a nice fuel efficient option for lighter E-350 motorhomes; provided it fits under doghouse.
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Old 09-30-2020, 08:44 PM   #17
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It's all in how you want the power delivery to occur.
An 8000 rpm redline serves no useful purpose in an RV.
But's it's cool in a ponycar
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Old 09-30-2020, 10:20 PM   #18
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Originally Posted by Chance View Post
It’s interesting that even in pickup tune, the 2021 Ford F-150’s 5.0L V8 can make more power at same RPM than the Ford 6.8L V10 in Class Cs and Axis/Vegas. Granted, power ratings may be on different basis.

5.0L V8 = 410 lb-ft at 4,250 RPM = 332 HP.

That beats the V10’s maximum of 305 HP at same 4,250 RPM.

The V10 only produces 377 lb-ft at 4,250 RPM.

If Ford upgraded 5.0L V8 to iron block for durability, I could see it making a nice fuel efficient option for lighter E-350 motorhomes; provided it fits under doghouse.
Class 5 and 6 trucks have to meet a different fuel standard the light trucks class 1. 2020 standards are 4.6464 gallons of fuel/100bhp-hour. Revving the 7.3 V-8 over 3,900 rpm and the engine cannot meet the the fuel consumption standards so there is a sharp cutoff in fuel and spark to limit the power produced. Class 1-3 trucks do not face the same restrictions. The 7.3 V-8s are all the same except for the computers. The V-10 faced the same fuel restriction in 2016 of 4.93 gallons/100bph-h and thus were limited to 3,900 rpm also to meet the standard. Attached is a 5 Star 2020 Thor Hurricane chassis dyno test with their tune as opposed to the stock tune. The sharp drop off @ 4,700 rpm is due to the fuel injectors duty cycle limitations. Larger injectors would extend the HP and tongue curves to the 5,200 rpm the engine's red line.
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Old 10-01-2020, 12:12 AM   #19
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Originally Posted by Chance View Post
It’s interesting that even in pickup tune, the 2021 Ford F-150’s 5.0L V8 can make more power at same RPM than the Ford 6.8L V10 in Class Cs and Axis/Vegas. Granted, power ratings may be on different basis.

5.0L V8 = 410 lb-ft at 4,250 RPM = 332 HP.

That beats the V10’s maximum of 305 HP at same 4,250 RPM.

The V10 only produces 377 lb-ft at 4,250 RPM.

If Ford upgraded 5.0L V8 to iron block for durability, I could see it making a nice fuel efficient option for lighter E-350 motorhomes; provided it fits under doghouse.
I'd seriously consider an engine swap but uneducated on motor mount design/location, transmission match, drive shaft length and doghouse.
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Old 10-01-2020, 12:14 AM   #20
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Originally Posted by Bob Denman View Post
It's all in how you want the power delivery to occur.
An 8000 rpm redline serves no useful purpose in an RV.
But's it's cool in a ponycar
An 8g motor is cool in any car. Indy gets 10+ but they have no regs.

Had a road runner with a 383. She'd top out at 7.5 and the stuff would start to float so he couldn't go any more.
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