The New 6.8L V8 Thread

[ESP08]

1 hour ago, Bob Rosadini said:

 Again my argument IS the 6.8 will appeal to a lot of buyers who are turned off by an OHC V-8.  And GM and Ram offer good alternatives,

 

I would say 99% of truck buyers don't actually know the difference between an OHV and OHC valve-train. 

And the counterpoint to that is Ford has more than held off GM & Ram sales for 23 years exclusively with OHC gasoline engines. 

I would argue Ford established even more dominance in the pickup market from 1997-2020 than they had through the 70s and 80s.  

 

GM AFM V8s have had low oil pressure/collapsed lifter concerns for a long time and Hemis have become notorious for the tick/failed lifter/cam (class action lawsuit is happening).  I think the allure of pushrod simplicity for the typical consumer died 10 years ago. 

 

Loudmouth LS fanboys on car message boards are a tiny fraction of the pickup market, IMO.  

Edited September 19, 2022 by ESP08

[Bob Rosadini]

58 minutes ago, ESP08 said:

 

I would say 99% of truck buyers don't actually know the difference between an OHV and OHC valve-train. 

And the counterpoint to that is Ford has more than held off GM & Ram sales for 23 years exclusively with OHC gasoline engines. 

I would argue Ford established even more dominance in the pickup market from 1997-2020 than they had through the 70s and 80s.  

 

GM AFM V8s have had low oil pressure/collapsed lifter concerns for a long time and Hemis have become notorious for the tick/failed lifter/cam (class action lawsuit is happening).  I think the allure of pushrod simplicity for the typical consumer died 10 years ago. 

 

Loudmouth LS fanboys on car message boards are a tiny fraction of the pickup market, IMO.  

As a Ford stockholder of significance I appreciate your comments and hope you are correct. I guess my problem is as an old retired guy I don't play golf and spend too much time hanging out with the wrong people....they do know the difference between OHC and OHV..as well as flatheads?

[Bob Rosadini]

2 hours ago, blksn8k2 said:

 I see this more along the lines of the old 385 series big blocks. The 429 and 460 shared the same bore size but used different crankshaft stroke dimensions. I also don't think we can dismiss the fact that the 6.2L Boss uses the same bore spacing and main bearing journal sizes as the 7.3L Godzilla. It would seem to be almost too easy to say you could simply use the 6.2 crank in a 7.3 block. BTW, that does result in 6.8L of displacement assuming you do not change the bore diameter of the 7.3 block. The only argument against a 6.8L in that configuration might be that big bore/short stroke engines have historically not been the best way to produce good low rpm torque which is what you would probably prefer for a truck application. 

As to your point, if the bore spacing is the same, a smaller piston would address the concerns raised by 7M3 and others??  So it COULD in fact be the same block?? Another positive for economies of scale-I would think?

As to your point on bore/stroke, and to again show my age, when the Super Duty gas engines were around starting in '58, they hyped "short stroke design".  I went to my "archives"- the 401 was 4.12 x 3.75, the 477 was 4.50 x 3.75, and the 534 was 4.50  x 4.20.  And before emission controls killed them they did very well.  And as for torque all three maximized it at 2000 RPM.  High RPM's I think  when compared to the 7.3.

[7Mary3]

I don't have a concern with the bore spacing or cylinder wall thickness of the 7.3L, I think it's adequate for the engine's intended use.  I brought it up in the context that if the 6.8L featured an aluminum block, the reduction in displacement might be in the bore to facilitate sleeves or increased cylinder wall thickness.  

[edselford]

• Wewq3. I guess we will have to Wait to see if 6.8 only has port injection????

I do not disagree with your statements on RAM, or 6.8 in F150.

RAM has been the big winner so far based on volume increases versus ten years ago. I doubt that most of the increased volume is due to pushrods vs OHC.  They sold the new Ram with the old Ram trucks for quite some time!  About $2200 difference in price!

At first, I thought the volume was coming out of Chevy/GMC. It may warrant a closer look with F150 volumes too. 

Also before the Coyote 5.0 V8 came out, there was a prior generation 5.8 DOC V8 in the Mustang., tall deck 5.4 bored out to 93.5mm in aluminum with PWT bore coating.

In the same F250 or F350 I would think the 6.8 would get better fuel mileage than the 7.3.

May be Ford hedging their bet with Hydrogen/LNG technology maturing at least in commercial applications with IC engines.

Just think of a 6.8 ecoboost fueled with hydrogen in the not too distant future as an alternative to pure EV.

[7Mary3]

Ford is indeed working on a hydrogen F-550, but it uses a fuel cell, not an ICE.  Hydrogen fueled ICE's are very inefficient compared to fuel cells, so barring some technological breakthrough it's likely they won't amount to much.

 

LNG isn't any cleaner than CNG, and neither is much better than gasoline from an emissions standpoint.

 

The 6.8L is 'Ford Blue', so I don't expect a lot of new innovations on the ICE side going forward.   

[SoonerLS]

8 hours ago, ESP08 said:

The 6.8 will add nose weight 

I thought that, too, but the last numbers I saw put Godzilla's weight at about 150lbs more than either the Coyote or EB35 (I can't recall which). If they go to an aluminum block and heads, even if it's the same external dimensions as Godzilla, the 6.8 wouldn't be significantly (if at all) heavier than the current F-150 powerplants.

[SoonerLS]

I still think the hybrid/PowerBoost setup is where Ford could make bank. They've played up the ability to power a job site with the F-150 PowerBoost; with a PowerBoost SuperDuty you could tow the equipment to the site as well as power it...

[blksn8k2]

4 hours ago, Bob Rosadini said:

As to your point, if the bore spacing is the same, a smaller piston would address the concerns raised by 7M3 and others??  So it COULD in fact be the same block?? Another positive for economies of scale-I would think?

As to your point on bore/stroke, and to again show my age, when the Super Duty gas engines were around starting in '58, they hyped "short stroke design".  I went to my "archives"- the 401 was 4.12 x 3.75, the 477 was 4.50 x 3.75, and the 534 was 4.50  x 4.20.  And before emission controls killed them they did very well.  And as for torque all three maximized it at 2000 RPM.  High RPM's I think  when compared to the 7.3.

 

Just to be clear, by using the 6.2 crank in the 7.3 block you get 6.8L without changing the 7.3's bore size which also means no change to piston size.

 

The displacement formula for an engine is Area of the Bore (πr²) x Crankshaft Stroke x Number of Cylinders. So, for an engine having a 4.22" bore (7.3L block) and 3.74" stroke (6.2L crank), the calc would be (4.22"÷2)² x π x 3.74" x 8 = 418.48 cu in or 6.858L.

 

And just to show my age, the old adage that a big bore/short stroke engine was always considered to be a quicker revving engine that made peak power at a higher rpm compared to a small bore/long stroke engine and this was best illustrated when comparing a 427 FE (big bore/short stroke) to a 428 FE (small bore/long stroke). The 427 was a better race engine when compared to a 428 which was actually a better street engine due to it's lower rpm torque output. 

[ESP08]

1 hour ago, SoonerLS said:

I thought that, too, but the last numbers I saw put Godzilla's weight at about 150lbs more than either the Coyote or EB35 (I can't recall which). If they go to an aluminum block and heads, even if it's the same external dimensions as Godzilla, the 6.8 wouldn't be significantly (if at all) heavier than the current F-150 powerplants.

I was assuming they retain the iron block since it’s going into 250/350.

[SoonerLS]

34 minutes ago, ESP08 said:

I was assuming they retain the iron block since it’s going into 250/350.

I'm assuming they'll keep the iron block for the SuperDuty, but they'd likely need an aluminum block for the F-150. Admittedly, that makes less sense than only making an iron block SuperDuty version. 
 

If they use it as a PowerBoost drivetrain, they might be able to at least partly offset that extra 150lbs for the iron block by moving the battery packs towards the rear. The F-150's powertrain already sits mostly behind the front axle (at least the Coyote in my '13 does), so it wouldn't take much to balance it out.

 

Now, in a Mustang, it might be a totally different story...

[fordmantpw]

11 hours ago, SoonerLS said:

I still think the hybrid/PowerBoost setup is where Ford could make bank. They've played up the ability to power a job site with the F-150 PowerBoost; with a PowerBoost SuperDuty you could tow the equipment to the site as well as power it...

 

Agreed.  Not to mention, it's easy to power an RV that you are towing behind you.

 

A PowerBoost Super Duty may just be enough to pry me away from my PowerStroke.  And I think that may be some concern for Ford in offering it in a Super Duty.

[Bob Rosadini]

16 hours ago, blksn8k2 said:

 

Just to be clear, by using the 6.2 crank in the 7.3 block you get 6.8L without changing the 7.3's bore size which also means no change to piston size.

 

The displacement formula for an engine is Area of the Bore (πr²) x Crankshaft Stroke x Number of Cylinders. So, for an engine having a 4.22" bore (7.3L block) and 3.74" stroke (6.2L crank), the calc would be (4.22"÷2)² x π x 3.74" x 8 = 418.48 cu in or 6.858L.

 

And just to show my age, the old adage that a big bore/short stroke engine was always considered to be a quicker revving engine that made peak power at a higher rpm compared to a small bore/long stroke engine and this was best illustrated when comparing a 427 FE (big bore/short stroke) to a 428 FE (small bore/long stroke). The 427 was a better race engine when compared to a 428 which was actually a better street engine due to it's lower rpm torque output. 

Glad to hear I'm not the only old fart?here.  My second new car after I  graduated was a 68 Torino GT, 428 C-6 4.30 gears- and a Notchback as opposed to a fastback- probably would be a rare car today on BJ or Mecom.  In anycase I thought the blocks were the same and 428 vs 427 was a marketing gimmick.  In my mind the only difference was solid lifters in 427 and hydraulics in 428.  Thanks for education.

[ESP08]

21 hours ago, blksn8k2 said:

And just to show my age, the old adage that a big bore/short stroke engine was always considered to be a quicker revving engine that made peak power at a higher rpm compared to a small bore/long stroke engine and this was best illustrated when comparing a 427 FE (big bore/short stroke) to a 428 FE (small bore/long stroke). The 427 was a better race engine when compared to a 428 which was actually a better street engine due to it's lower rpm torque output. 

 

The reality is that over-square engines tend to make more high rpm power because they also tend to have more intake valve area relative to total displacement than an under-square engine does.   

This is especially true of in-line valve 2-valve/cylinder engines.  

 

The "mechanical advantage" provided by a longer stroke is so minuscule it's essentially irrelevant.

Where the power/torque is made is almost entirely found in how well the top end (intake manifold runner length/cross section, intake port cross section/angle, intake valve area/angle/placement in the chamber, cam timing, etc.) can feed the total displacement underneath it.    

 

Larger ports and valves inherently tend to shift the power-band north, smaller valves and ports tend to bring on power earlier.   

 

Under-square multivalve engines tend to retain high-rpm capability (if desired) because they aren't intake valve area limited (or valve shrouded) relative to their total displacement by a smaller bore.   

 

 

Edited September 20, 2022 by ESP08

[jpd80]

In the grand scheme of things, I don’t think that a 3.74” stroke is exactly short stroke and is a mere two tenths of an inch shorter stroke than the crank in the 7.3 V8.

 

Whats probably more appropriate here is the increasing stringency of new and proposed emission regulations for heavy duty trucks, this more than anything is probably forcing changes to more efficient engines and greater consideration of electrification into fleet sales.

 

Quote

EPA to consider tougher emissions rules for heavy trucks

https://www.autonews.com/regulation-safety/epa-consider-tougher-emissions-rules-heavy-trucks

The consideration comes after Congress passed new incentives to speed the adoption of zero-emission vehicles.

September 21, 2022 10:25 AM UPDATED 3 HOURS AGO

WASHINGTON - The U.S. Environmental Protection Agency (EPA) will consider adopting more stringent greenhouse gas emissionsrules for heavy trucks after Congress passed new incentives to speed the adoption of zero-emission vehicles, the agency told Reuters.

In March, the EPA proposed new rules to cut smog-forming and greenhouse gas (GHG) emissions from heavy duty vehicles. The agency said it will reopen the proposed GHG rules after passage in August of the climate and spending Inflation Reduction Act(IRA).

 

The Truck & Engine Manufacturers Association, representing which companies such as Daimler Trucks, Caterpillar and Cummins, previously raised concerns the EPA proposal could boost costs and result in customers keeping "their higher emitting trucks longer."

EPA will be issuing a supplemental notice of proposed rulemaking to consider more stringent GHG standards for model years 2027 through 2029 in December.

EPA Office of Air and Radiation official Joseph Goffman told Reuters "the big change here is the Inflation Reduction Act. Congress definitely sent a very strong message backed by significant resources."

EPA believes much greater zero emission vehicle adoption rates are possible for 2027 through 2029.

The EPA still plans to finalize the proposed smog-forming truck rules by December.

 

Non-profit RMI said the IRA's up to $40,000 Qualified Commercial Clean Vehicle tax credit "will turbocharge adoption of electric medium-duty and heavy-duty trucks," and will make electric trucks cheaper to operate than diesels in most cases.

In March, EPA said the new heavy truck GHG standards when fully phased in would result in up to 24-25 percent lower CO2 emissions.

EPA in March proposed tighter standards for 17 of the 33 subcategories of vocational and tractor vehicles including school buses, transit buses, commercial delivery trucks, and short-haul tractors.

Transportation is the largest source of U.S. GHG emissions, making up 29 percent of emissions and heavy-duty vehicles are the second-largest contributor, at 23 percent, the EPA said.

 

 

Things are changing faster than most can imagine and just marking time to whatever has always been is not going to cut it. The Feds are out to make revolutionary change here and make no mistake, buyer preferences on repeat business is all changing but can truckmakers like Ford react fast enough to please rulemaker and their own buyers….

[jpd80]

Ending 6.2 means that Ford can close down Romeo plant. Replacing the 6.2 with a 6.8 based on the 7.3 but with minimal changes like shorter stroke  and longer con rods is probably good use with minimal parts change. Such a 6.8 would have commonality  with 7.3 for engine compartment layout and accessories, simplifying production line, the 6.8 would also have more low down torque than the 6.2 and in heavy duty trucks, capacity is everything.

 

Edited September 21, 2022 by jpd80

[akirby]

1 hour ago, jpd80 said:

Ending 6.2 means that Ford can close down Romeo plant. Replacing the 6.2 with a 6.8 based on the 7.3 but with minimal changes like shorter stroke  and longer con rods is probably good use with minimal parts change. Such a 6.8 would have commonality  with 7.3 for engine compartment layout and accessories, simplifying production line, the 6.8 would also have more low down torque than the 6.2 and in heavy duty trucks, capacity is everything.

 

But why keep both?  

[jpd80]

27 minutes ago, akirby said:

But why keep both?  

There’s a fast approaching need for better fuel efficiency/ emissions requirement  with F250 and F350,

the 6.8 could give them breathing space with that until the BEV Super Duty is ready…

[akirby]

1 hour ago, jpd80 said:

There’s a fast approaching need for better fuel efficiency/ emissions requirement  with F250 and F350,

the 6.8 could give them breathing space with that until the BEV Super Duty is ready…

Then drop the 7.3.  Keeping both makes zero sense.

[jpd80]

27 minutes ago, akirby said:

Then drop the 7.3.  Keeping both makes zero sense.

If Ford is still going ahead with this next year, your argument will be with them…not me.

Things are changing fast, I personally though 7.3 with different power levels would be enough….

Edited September 21, 2022 by jpd80

[ESP08]

26 minutes ago, akirby said:

Then drop the 7.3.  Keeping both makes zero sense.

 

650/750 need all the low-end torque they can get.    

 

Sounds like Ford wants to give 250/350 something more fuel efficient than 7.3 to act as their base engine 6.2 replacement.  

[akirby]

35 minutes ago, ESP08 said:

 

650/750 need all the low-end torque they can get.    

 

Sounds like Ford wants to give 250/350 something more fuel efficient than 7.3 to act as their base engine 6.2 replacement.  

Isn’t that why they make a turbo diesel?

[7Mary3]

48 minutes ago, akirby said:

Then drop the 7.3.  Keeping both makes zero sense.

 

Exactly.  Unless the 6.8L has some added tech. over the 7.3L like AFM, .5L les displacement is not going to make any meaningful difference in fuel economy.  Why not just make the 'economy' low H.P. 7.3L in the E series the standard engine in the Super Duty?  The 6.8L has to be different in some way.

Edited September 21, 2022 by 7Mary3

[ESP08]

21 minutes ago, akirby said:

Isn’t that why they make a turbo diesel?

 

Yes, but:

2023 F-650/750 SD Gas Pro Loader - $65,520

2023 F-650/750 SD Diesel Pro Loader - $75,005

 

Diesel will also have higher maintenance costs and diesel typically runs $1 or more per gallon than 87.  

 

[ESP08]

28 minutes ago, 7Mary3 said:

 

Exactly.  Unless the 6.8L has some added tech. over the 7.3L like AFM, .5L les displacement is not going to make any meaningful difference in fuel economy.  Why not just make the 'economy' low H.P. 7.3L in the E series the standard engine in the Super Duty?  The 6.8L has to be different in some way.

 

Perhaps 6.8 is smaller bore with cylinder deactivation