Rinzler

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Engineering is frequently forced to work within constraints that aren't of engineering's own choosing. IOW, do the best you can with what you're given, as long as you stay inside the big box.

Perhaps the poster-boy example of that within the automotive world is one of the cars you just mentioned. I'm talking about the 911 Porsche and its rear engine. If it hadn't been for continuing engineering development over the past 55 years, it would have long ago been consigned to the dustbins of automotive history under 'things that might have had promise but didn't work out'.

Closer to home and as good as they are, both the Coyote and the Voodoo have also had to develop under constraints that you wouldn't choose if your primary focus was on power and performance.


Norm
I definitely agree with the sentiment and sure, if you want to try to squeeze the last 5% of performance out of a front engine car, you can definitely do that. However, you do run into diminishing returns. The amount of work and effort to get the last percentage is exponentially higher than it may be worth. I would argue the 13 BOSS 302 Laguna Seca is a good example of the pinnacle of Ford's effort for a live axle performance car. That car outran M3s, then they developed the S550 PP1, which subsequently outran the BOSS 302. Another example in the Porsche/Ford example is the base 911, with it's 379 horsepower, runs the quarter mile in the same time (not trap speed obviously) as the GT500 (real world not manufac. claimed).

So to you point, yes, is it possible to throw money and engineering at the problem? Absolutely! However, physics is absolute and in this case, it has been proven over the years that weight is the enemy of performance. If the current GT500 isn't a smoking gun, I don't know what is.

Overall, my point was simply to say that a bigger 6.8L engine doesn't give people the solution they think it does. Sure, you can brag about a large displacement number, however, you run into the Dodge Hellcat scenario where you're still losing to cars that have more sound engineering principles for what the end goal is.
 

martinjlm

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There's no reason that a derivative of this 6.8 couldn't be a decent powerplant for a Mustang. No reason it'd have to have a cast iron block, for starters. Or the full 6.8L, for that matter (390 does have a nice ring to it if you're a Ford, Mustang, or Bullitt fan).


Norm
Manufacturing process and cost would be the big issue. Whether it’s in house or purchased, somebody has to cast the thing. Casting iron and aluminum are different processes requiring some differences in design, unless you are willing to sub-optimize the design of one in favor of the other. So we’re looking at the cost of two similar but different block designs. Low volume casting in aluminum is expensive.

Then machining of the blocks is different. For some operations, the equipment may be the same, but the perishable cutting tools are significantly different for cast iron and aluminum. The likelihood that Ford would spend the capital to have parallel but different manufacturing processes for a low volume 7.3L cast iron engine and an even lower volume 6.8L aluminum engine are pretty slim. They have far more pressing issues to spend money on.

If there is a Mustang 6.8L engine, it will no doubt be cast iron. And that would be a heavy beast to put under the hood of an already front heavy car that’s s’posed to be at least halfway decent at cornering.

There was a time where GM had both cast iron and aluminum versions of the 5.7L and 6.0L V8 engines. But both configurations were high volume. Enough volume to support separate casting processes and separate production lines and plants. Aluminum was for cars, cast iron for trucks. Eventually all of the truck cast iron production was converted to aluminum.
 

Norm Peterson

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I think we need a 'Norm' driver feedback mode. The electronics won't intervene at all but if the electronics would have, it shocks the driver. 'tingle' mode for small values of out-of-range, big-ass jolt (think cattle fence) for larger. Resistance is not only futile, it's good for you. You WILL be assimilated.
Boy, do I have a challenge for you.

On a serious note, all I've ever needed was feedback from the contact patches and a sense of how much control inputting I was doing. Artificial approximations of that just get in the way. I flat-out can't "drive" a driving sim because the feedback feels all wrong, and the DMV would probably take my license away from me if I ever had to demonstrate driving competence to them on a simulator. No lie.


Norm
 

Erik427

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Manufacturing process and cost would be the big issue. Whether it’s in house or purchased, somebody has to cast the thing. Casting iron and aluminum are different processes requiring some differences in design, unless you are willing to sub-optimize the design of one in favor of the other. So we’re looking at the cost of two similar but different block designs. Low volume casting in aluminum is expensive.

Then machining of the blocks is different. For some operations, the equipment may be the same, but the perishable cutting tools are significantly different for cast iron and aluminum. The likelihood that Ford would spend the capital to have parallel but different manufacturing processes for a low volume 7.3L cast iron engine and an even lower volume 6.8L aluminum engine are pretty slim. They have far more pressing issues to spend money on.

If there is a Mustang 6.8L engine, it will no doubt be cast iron. And that would be a heavy beast to put under the hood of an already front heavy car that’s s’posed to be at least halfway decent at cornering.

There was a time where GM had both cast iron and aluminum versions of the 5.7L and 6.0L V8 engines. But both configurations were high volume. Enough volume to support separate casting processes and separate production lines and plants. Aluminum was for cars, cast iron for trucks. Eventually all of the truck cast iron production was converted to aluminum.
The 6.8 if it does happen will be a much higher volume engine than the 7.3
F-150 sales are much higher than F-250 and so on.

I am hoping for a alloy block.
 

martinjlm

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The 6.8 if it does happen will be a much higher volume engine than the 7.3
F-150 sales are much higher than F-250 and so on.

I am hoping for a alloy block.
True, but F-150 already has how many engine options? And what percentage of those would you expect to opt for the 6.8L? It will be a small number. Whereas for F-250/350 7.3L is THE gas engine. The 7.3L will definitely be the higher volume of the two.
 

Norm Peterson

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If there is a Mustang 6.8L engine, it will no doubt be cast iron. And that would be a heavy beast to put under the hood of an already front heavy car that’s s’posed to be at least halfway decent at cornering.

There was a time where GM had both cast iron and aluminum versions of the 5.7L and 6.0L V8 engines. But both configurations were high volume. Enough volume to support separate casting processes and separate production lines and plants. Aluminum was for cars, cast iron for trucks. Eventually all of the truck cast iron production was converted to aluminum.
That last is why I think it'd make some sense for the smaller engine, designed for lighter duty, to end up in aluminum and be a more reasonable choice for a Mustang. If nothing else, it might give the lighter-duty pickups a bit more payload capability.

I haven't yet seen where this 6.8 is itself a 7.3 derivative.


Norm
 

Elp_jc

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My favorite example of this is “the factory engineers recommend xyz motor oil so it just be good.” Ok, but if the engineer had his own performance car, would he personally use what is printed in the manual?
My guess is in many cases, nope :). If the EPA and lawyers didn't exist, and there were no fuel mileage points or restrictions, then I'd probably follow all manufacturer recommendations :angel:. But the reality is in many cases, those recommendations are not the best for you, your engine, or whatever they're intended to benefit; they're appease a government agency, to minimize potential lawsuits, to save them money, etc.
 

Norm Peterson

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Correct Norm. My favorite example of this is “the factory engineers recommend xyz motor oil so it just be good.” Ok, but if the engineer had his own performance car, would he personally use what is printed in the manual?
Not if his name happened to be Scott W.


Norm
 

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True, but F-150 already has how many engine options? And what percentage of those would you expect to opt for the 6.8L? It will be a small number. Whereas for F-250/350 7.3L is THE gas engine. The 7.3L will definitely be the higher volume of the two.
I can see the much more expensive Coyote and 3.5 TT being killed off.
Just look at the fe gm is getting with their V-8 options....
 

martinjlm

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I can see the much more expensive Coyote and 3.5 TT being killed off.
Just look at the fe gm is getting with their V-8 options....
Not likely. Coyote is main production installation at Essex. Ford would have to retire the Essex plant if they were to take the 5.0L out of F-150. Mustang volume is nowhere near enough to keep a plant that size open on its own.

3.5TT production is installed at Cleveland. Again, a pretty sizable module and it’s used in far more vehicles than the 6.8L is planned to go into. The likelihood of the 6.8L replacing either of those engines is slim to none. And if those two aren’t going away, 6.8L would only see limited volume in an F-150. It would depend on how Ford prices the options. Right now the 5.0L is $2,000 above base engine. 3.5TT is another $600 over the V8 and customers are checking those two boxes like crazy. So where would Ford slot the 6.8L price-wise if they want to keep ringing the cash register for the 5.0 and the 3.5TT? If they price it higher, it won’t get enough volume to displace either engine. If they price it lower, Ford leaves money on the table compared to where they are now.

More likely they will make the 6.8L available for F250/350 Super Duty as a replacement for the 6.2L that is being retired. Not for F-150. The fact that it will be built in Windsor in the same plant, probably the same line as the 7.3L lends to the idea that it is based on the 7.3 and will be used in similar vehicles. And that it is cast iron block, just like the 7.3L, and therefore too heavy for the front end of a Mustang. It’s basically, Baby Godzilla.
 

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Not likely. Coyote is main production installation at Essex. Ford would have to retire the Essex plant if they were to take the 5.0L out of F-150. Mustang volume is nowhere near enough to keep a plant that size open on its own.

3.5TT production is installed at Cleveland. Again, a pretty sizable module and it’s used in far more vehicles than the 6.8L is planned to go into. The likelihood of the 6.8L replacing either of those engines is slim to none. And if those two aren’t going away, 6.8L would only see limited volume in an F-150. It would depend on how Ford prices the options. Right now the 5.0L is $2,000 above base engine. 3.5TT is another $600 over the V8 and customers are checking those two boxes like crazy. So where would Ford slot the 6.8L price-wise if they want to keep ringing the cash register for the 5.0 and the 3.5TT? If they price it higher, it won’t get enough volume to displace either engine. If they price it lower, Ford leaves money on the table compared to where they are now.

More likely they will make the 6.8L available for F250/350 Super Duty as a replacement for the 6.2L that is being retired. Not for F-150. The fact that it will be built in Windsor in the same plant, probably the same line as the 7.3L lends to the idea that it is based on the 7.3 and will be used in similar vehicles. And that it is cast iron block, just like the 7.3L, and therefore too heavy for the front end of a Mustang. It’s basically, Baby Godzilla.
The 7.3 and it's variants will be much cheaper to build.
Demand will decide who lives and dies when it comes to these engine families.

There are early rumors of a alloy smaller displacement version of the 7.3, only time will tell.

I can say it's been since 1973.........Time to match gm in displacement.
 

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^^^ I'm more expecting GM to bring their engines down in displacement to more closely match Ford . . . no, that doesn't fit the 'more's better, too much is just enough' mindset very well, though.


Norm
 

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^^^ I'm more expecting GM to bring their engines down in displacement to more closely match Ford . . . no, that doesn't fit the 'more's better, too much is just enough' mindset very well, though.


Norm
It will be tough for them to match the power at equivalent displacement if they don’t go to dohc. Just look at their feeble efforts to bump the 5.3 up to 355 hp (383 ftlb) to match the gen1 coyote’s 360. It was sad. Then the f-150 coyote was bumped to 380, 395, and now 400/410.
 

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GM already has a 5.5L DOHC V8, and it's apparently not related to the late Cadillac Blackwing project. They just aren't saying a whole lot about it. But I can see there being some sense for GM to keep such an engine at 5.5L if it was to end up as regular production, just to slightly "one-up" the Coyote/Voodoo.


Norm
 

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It will be tough for them to match the power at equivalent displacement if they don’t go to dohc. Just look at their feeble efforts to bump the 5.3 up to 355 hp (383 ftlb) to match the gen1 coyote’s 360. It was sad. Then the f-150 coyote was bumped to 380, 395, and now 400/410.
GM already has a 5.5L DOHC V8, and it's apparently not related to the late Cadillac Blackwing project. They just aren't saying a whole lot about it. But I can see there being some sense for GM to keep such an engine at 5.5L if it was to end up as regular production, just to slightly "one-up" the Coyote/Voodoo.


Norm
I can say with some authority that GM doesn't give a $#!t about specific power (hp/L). At least not when it comes to comparing different configurations. I spent more than 10 years leading a team that kept the Engine Engineering speed up to date on competitor specs, including specific power. They compared specific power of OHV to OHV and OHC to OHC. When comparing across configurations, the discussion was more on rated output, ignoring displacement. Even then, when we told Al O. that Mustang was bumping to 460 hp (and then 480) his response was basically "meh".
 
 
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