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The New 6.8L V8 Thread


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Bob, I agree- I don't support big subsidies for electric vehicles either, and at this point it's hard to tell if electrics will take 20% or 80% or whatever % of the medium market. Still hard to make an argument for investing in a big gas V8 now, though it made sense in the 1950s. But the money's spent and it ain't a bad engine, may as well make the most of it!

 

jpd80, nothing wrong with looking for markets beyond new Ford trucks for the 7.3- Crate engines, industrial engines, etc. are profitable "icing on the cake" for Ford.

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22 minutes ago, GearheadGrrrl said:

Bob, I agree- I don't support big subsidies for electric vehicles either, and at this point it's hard to tell if electrics will take 20% or 80% or whatever % of the medium market. Still hard to make an argument for investing in a big gas V8 now, though it made sense in the 1950s. But the money's spent and it ain't a bad engine, may as well make the most of it!

 

jpd80, nothing wrong with looking for markets beyond new Ford trucks for the 7.3- Crate engines, industrial engines, etc. are profitable "icing on the cake" for Ford.

I’m simply pointing out the latter as some on this forum appear disappointed that Ford didn’t deliver the engine they wanted, all I’d say to that is we haven seen the second part of the performance development program, Ford in fact remaining very tight lipped about the 6.8…..

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It’s also clear this engine was developed specifically for F series pickups.  Assuming Ford averages $10k profit on each truck (which is probably low) and it goes in 200k per year for the next 5 years that’s $10B in profit.  That is the business case not as a crate engine or for use in a low volume hipo mustang - those are gravy.   And because the business case is F series it was designed to meet the production requirements for cost, durability and fuel economy - not so that somebody can supercharge it and make 1500 hp.

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9 hours ago, jpd80 said:

Brian Wolfe was Ford Program director in charge of 7.3’s development, sure he had dual purpose in developing an engine that could be used two ways - a modern take on an enlarged Windsor that had enough capacity to cover Super and Medium Duty as well as E Series and the Stripped Chassis twins.  As a crate engine with compact dimensions afforded by a wedge head means that people who used to buy aftermarket 427 Windsors now have a viable alternative.

JP-Totally understand Bob Wolf's role and have watched many of his videos as they tweak the 7.3-emphasizing again what I believe its PRIMARY mission was.

In any case, sure is nice that it can.."hit from both sides of the plate".

I'm disappointed now however as my local dealer says an air brake option for it has been canceled for 750-something to do with underhood air temps-sounds like a bullshit excuse to me.

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12 minutes ago, Bob Rosadini said:

JP-Totally understand Bob Wolf's role and have watched many of his videos as they tweak the 7.3-emphasizing again what I believe its PRIMARY mission was.

In any case, sure is nice that it can.."hit from both sides of the plate".

I'm disappointed now however as my local dealer says an air brake option for it has been canceled for 750-something to do with underhood air temps-sounds like a bullshit excuse to me.

Correction- I"M emphasizing what I believe its primary purpose was...medium duty trucks.  the gearheads all saw potential to challenge the BBC.

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1 hour ago, Bob Rosadini said:

Correction- I"M emphasizing what I believe its primary purpose was...medium duty trucks.  the gearheads all saw potential to challenge the BBC.


Well I don’t see how anyone can come up with a different conclusion.  And it’s perfectly fine to say I wish they had done this or that, but to say that Ford made some mistake by investing in that engine given its importance to the super duty over the next 5-10 years or to say that they made a mistake because it can’t be hot rodded is just ridiculous   Bench racing is so stupid.

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From what I understand, the 7.3L was designed to replace the 6.8L V-10 and eventually the 6.2L V-8 in the Super Duty line.  It was not expressly designed for the medium duty trucks as their volume was nowhere near large enough to justify a specific engine, but nonetheless the 7.3L was at least designed with an eye towards those applications.  I am also hearing that it was really designed 'on the cheap', inheriting bore spacing and crankshaft dimensions from the orphan 6.2L 'Boss' family.  Sounds like a lot of money was saved on tooling!  Due to the 7.3L's simple OHV configuration, small external size, large displacement, and decent cylinder heads one would have to be blind not to see the high performance potential in it.  However, I don't see Ford doing much with this engine from a high perfomance standpoint.  It's not going into the Mustang or F-150, and the rumors of a aluminum 6.8L version seem to be nothing more than rumors.  Even Brian Wolfe admitted that Ford 'performance' V-8 would remain the Coyote.  The 'crate' 7.3L offered now by Ford is nothing more than a current production dressed (expensive!) engine right out of a Super Duty.  It is looking like it will be up to the aftermarket to do something with this engine.  And it certainly looks like they will!  But, I am afraid that means once again the Ford alternative to the Chevy high performance engine (LS in this case) will be significantly more expensive and likely not capable of the same power output, particularly from a dollars-to-horsepower standpoint.  Nonetheless I look forward to seeing what guys like Brian Wolfe will do to the 7.3L.

 

   

 

 

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So I get a completely different picture of the 7.3. 
 

It’s not unusual at all for succeeding engines to share bore spacing. Yes it does apparently affect the bottom line. In fact bore spacing is THE limitation of the Coyote engine. 
 

But c’mon guys are we really gonna play this game? Brian Wolfe was chief engineer  of this 7.3 project when it began. He has since retired from Ford but his thumbprints are all over this engine. 

I’m not talking about the obvious stuff like the Coyote tech intake manifold or the nearly vertical intake ports. No

 

I am talking about a 60mm camshaft and also that camshaft’s position high up in the block. 
 

I’m talking about 2.200” installed height on the valves conveniently facilitating huge cam lobe lift.  
 

I’m talking about the block structure itself especially around the cylinders and deck area aimed at supporting the head gasket well in excess of its factory power rating. 
 

I’m talking about canted valves. 
 

I was fortunate enough to hear the comments live on a podcast by Darin Morgan (cylinder head developer extraordinaire) about how good the basic head was and what an excellent job the designers did by blessing the engine with good airflow, fuel/air mixing and good burn characteristics. 
 

As it stands the 7.3 at 4.53” B/S is greater than the LS/LT at 4.4” and the Gen III Hemi at 4.46”.

 

Why would Ford need a larger bore spacing than that? They already theoretically have more meat between the cylinders for good head gasket retention at a given bore size. 
 

This engine is truly a 460 replacement but with the external size of approximately a 351W. 
 

I don’t even want to get into the 2 valve pushrod versus DOHC 4 valve psychology but suffice it to say that both have their place. This 7.3 is going to satisfy A HUGE pent up demand for a Ford based performance platform that follows the traditional pushrod American V8 monster engine. 
 

 

 

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53 minutes ago, Stray Kat said:

I’m talking about the block structure itself especially around the cylinders and deck area aimed at supporting the head gasket well in excess of its factory power rating. 


Why would Ford need a larger bore spacing than that? They already theoretically have more meat between the cylinders for good head gasket retention at a given bore size. 
 

 
 

 

 

 

 

I agree with everything you said but I would like to comment on those to points.  Yes, the bore spacing is marginally larger than the LS, but since the 7.3L has a larger bore, the space between bores is only 7.62 mm, compared with 8.51 mm for the LS/LT 6.2L and 6.6L.  The LS 6.0L has a substantial 10.6 mm between the bores (one reason why iron block 6.0L's can tolerate so much boost).  So you can see the 7.3L actually has less 'meat' between the cylinders than most LS/LT engines, which of course are smaller displacement.  The Godzilla's narrow deck surface between the cylinders is further compromised by the coolant passage saw cuts, a design that caused much trouble on various Ecoboost 4 cylinder engines.  Ford has designed the 7.3L with about the maximum bore the 4.53" bore centers can accomodate for a regular production 'truck' engine.  While I doubt any of this will cause issues in normal service, it likely means the 7.3L block will not tolerate much overbore and maximum boost remains a question.  I am hearing that the maximum allowable overbore for the 7.3L block is only 3mm (.011"), can anyone confirm?  I couldn't help but notice Brian Wolfe filled his block, welded up the cooling slots, and O-ringed the heads on his 7.3L maximum-effort blown race engine.  There are a number of pictures on the internet of 7.3L blocks cut horizontally below the deck and I can't say the thickness of the cylinder walls inspires a lot of confidence from an all-out race standpoint, but the block should be fine for it's intended applications.  If Godzilla's 4.53" bore spacing was dictated by the re-use of 6.2L 'Boss' tooling it looks like Ford gave the engine the largest displacement possible under those circumstances. 

 

And speaking of the 6.2L 'Boss', it's really too bad that engine turned out to be an orphan.  Could you imagine what that thing could have done with Coyote-style 4 valve heads?   

 

  

 

      

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3 hours ago, 7Mary3 said:

 

 

I agree with everything you said but I would like to comment on those to points.  Yes, the bore spacing is marginally larger than the LS, but since the 7.3L has a larger bore, the space between bores is only 7.62 mm, compared with 8.51 mm for the LS/LT 6.2L and 6.6L.  The LS 6.0L has a substantial 10.6 mm between the bores (one reason why iron block 6.0L's can tolerate so much boost).  So you can see the 7.3L actually has less 'meat' between the cylinders than most LS/LT engines, which of course are smaller displacement.  The Godzilla's narrow deck surface between the cylinders is further compromised by the coolant passage saw cuts, a design that caused much trouble on various Ecoboost 4 cylinder engines.  Ford has designed the 7.3L with about the maximum bore the 4.53" bore centers can accomodate for a regular production 'truck' engine.  While I doubt any of this will cause issues in normal service, it likely means the 7.3L block will not tolerate much overbore and maximum boost remains a question.  I am hearing that the maximum allowable overbore for the 7.3L block is only 3mm (.011"), can anyone confirm?  I couldn't help but notice Brian Wolfe filled his block, welded up the cooling slots, and O-ringed the heads on his 7.3L maximum-effort blown race engine.  There are a number of pictures on the internet of 7.3L blocks cut horizontally below the deck and I can't say the thickness of the cylinder walls inspires a lot of confidence from an all-out race standpoint, but the block should be fine for it's intended applications.  If Godzilla's 4.53" bore spacing was dictated by the re-use of 6.2L 'Boss' tooling it looks like Ford gave the engine the largest displacement possible under those circumstances. 

 

Since the 6.2 Boss is made at Romeo Engine Plant and the 7.3 is made at the Windsor engine plant, I’d doubt the 4.53” bore spacing was chosen to reuse equipment that’s still being used at another plant. More likely, the Boss architecture was probably used as a starting point to reduce time and money to develop, throw in finite element analysis and voila, an extremely robust engine architecture.

 

3 hours ago, 7Mary3 said:

And speaking of the 6.2L 'Boss', it's really too bad that engine turned out to be an orphan.  Could you imagine what that thing could have done with Coyote-style 4 valve heads?   

Ford has only allocated $112 million to developing the 6.8, a fraction of that expended developing design and plant for the 7.3. so anything happening is either a quick and dirty on Godzilla or a clever reuse/ relocation of Boss 6.2 line to Windsor with maybe a siamesed block….. what’re ever happens, Ford isn’t spending much to develop it.

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8 hours ago, 7Mary3 said:

And speaking of the 6.2L 'Boss', it's really too bad that engine turned out to be an orphan.  Could you imagine what that thing could have done with Coyote-style 4 valve heads?        

 

I am surprised that the aftermarket industry hasn't developed something along those lines...

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On 12/29/2021 at 9:17 AM, akirby said:


Well I don’t see how anyone can come up with a different conclusion.  And it’s perfectly fine to say I wish they had done this or that, but to say that Ford made some mistake by investing in that engine given its importance to the super duty over the next 5-10 years or to say that they made a mistake because it can’t be hot rodded is just ridiculous   Bench racing is so stupid.

This Forum wouldn't exist if you didn't have all the speculation and opinion. The Mach E is stirring up the same BS because Ford used the Mustang moniker. Ford's growth and advancement will succeed with Farley. 

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  • 3 months later...
10 hours ago, Captainp4 said:

Any new info on the 6.8? I'm all about the BEV transition and know it's the way they need to go, but I was really hoping for one last swing for the v8...

Wow! Your instincts are amazing. Check out this news article I found this morning. 
 

Tell me what one can infer from it. Is there a possibility of the 6.8 showing up in the F150 “and” the Mustang?

 

https://windsorstar.com/news/local-news/windsor-engine-plants-still-part-of-fords-long-term-plans

 

 

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8 hours ago, Stray Kat said:

Wow! Your instincts are amazing. Check out this news article I found this morning. 
 

Tell me what one can infer from it. Is there a possibility of the 6.8 showing up in the F150 “and” the Mustang?

 

https://windsorstar.com/news/local-news/windsor-engine-plants-still-part-of-fords-long-term-plans

 

 

 

First solid 6.8L news in months!  Still wonder exactly what it will be.

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19 hours ago, Stray Kat said:

Wow! Your instincts are amazing. Check out this news article I found this morning. 
 

Tell me what one can infer from it. Is there a possibility of the 6.8 showing up in the F150 “and” the Mustang?

 

https://windsorstar.com/news/local-news/windsor-engine-plants-still-part-of-fords-long-term-plans

 

That was what Jerry Dias was saying at the UNIFOR press briefing back in 2020

 

Whatever form the 6.8 takes, I just hope it’s trick enough to keep the GM guys honest,

it’s a good capacity to produce plenty of power and torque below 6,000, insane with boost…

Edited by jpd80
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10 hours ago, jpd80 said:

That was what Jerry Dias was saying at the UNIFOR press briefing back in 2020

 

Whatever form the 6.8 takes, I just hope it’s trick enough to keep the GM guys honest,

it’s a good capacity to produce plenty of power and torque below 6,000, insane with boost…

If it is a reality for the Mustang or even the F150 it’s a miss to not hit one of those legendary Ford SAE displacement numbers like 427, 428, or best of all 429CJ. 
 

If we’re going to say goodbye to ICE eventually give us old guys one last hurrah. 

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Just to add to that a little bit more. If the 6.8 is an alloy block do you guys realize that this engine would probably come in under the weight of a 351 Windsor? 
 

All day long I’d be advocating for a modern 429” CJ that weighs less than a small block of old. 
 

We’ve paid the price to get something like that by buying the Mach E in droves. 
 

One last legend Ford and please build crate engines so we can update some older Fords with real Ford power as well. 

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3 hours ago, Stray Kat said:

Just to add to that a little bit more. If the 6.8 is an alloy block do you guys realize that this engine would probably come in under the weight of a 351 Windsor? 
 

All day long I’d be advocating for a modern 429” CJ that weighs less than a small block of old. 
 

We’ve paid the price to get something like that by buying the Mach E in droves. 
 

One last legend Ford and please build crate engines so we can update some older Fords with real Ford power as well. 

 

It'll need 550+ HP N/A (or come factory boosted) to have a shot at legend status in today's environment, IMO.   

If it's a slightly warmed over 7.3 @ 6.8 liters it will most likely make less than the 5.2 Voodoo w/o electric assist.  

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3 hours ago, ESP08 said:

 

It'll need 550+ HP N/A (or come factory boosted) to have a shot at legend status in today's environment, IMO.   

If it's a slightly warmed over 7.3 @ 6.8 liters it will most likely make less than the 5.2 Voodoo w/o electric assist.  

It’s not always how it’s delivered but what it can become. 
 

There are plenty of Challenger buyers that may not want to sign up for a twin turbo I6. 
 

Cubic inches in the 7.0 liter range are known for torque and that feeling is exhilarating. 

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6 hours ago, ESP08 said:

 

It'll need 550+ HP N/A (or come factory boosted) to have a shot at legend status in today's environment, IMO.   

If it's a slightly warmed over 7.3 @ 6.8 liters it will most likely make less than the 5.2 Voodoo w/o electric assist.  

With regards to an Atmo pushrod engine,

I was just thinking about the 7.0 LS7 released in 2006, 570 hp @5,500 and 540 lbft @ 4,000, I have no doubt that the 6.8 could achieve those figures easily even with 0.2 litres less, no trick titanium rods or the constraints of 4” crank in a low deck height block.  For one, the bore should be bigger and the stroke less, allowing the engine to rev more easily and make use of big free flowing cylinder heads.


With regards to an Atmo OHC/multivalve engine,

And then I thought about the GM 5.5 liter DOHC LT6 that’s due in the Corvette, 670hp @8,400 and 460 lb ft @6,300. The shear presence of that engine is going to eclipse the 5.2 Voodoo engine because that’s what GM does. If the 6.8 is OHC or multivalve, it would approximate a big coyote with a third more capacity, now that has to easily match or eclipses the LT6’s power and torque at lower revs.

Edited by jpd80
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Very glad to hear that Ford is continuing with this engine. I look forward to seeing it (and its numbers) very soon. I know they mentioned that it would go in the Mustang and F-150, but I hope that somehow it ends up in a Bronco of some kind.

 

We know that the F-150 Raptor R is getting a V-8. Does anyone know if it was confirmed to be supercharged? Could the 6.8 really be this truck's engine the entire time?

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