Who will swap for the new 7.3 V8!

[Fatguy]

The current 6.7-liter Power Stroke generates 450 hp and 935 lb-ft of torque.

That engine looks good in paper but a diesel, so bad in winter, lousy exhaust and too heavy. 7.3 hits the spot but not perfect. But the only current Ford option.

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[Fatguy]

You know what’s better than options? Options you can switch on the fly! Options like being able to adjust cam timing on intake and exhaust independently to match every situation.... and to use port or direct injection or a blend.....and to alter intake runner geometry while you drive.....oh wait....the 5.0 does all that today!

Not the freakishly extreme options you have with the 7.3. That is what you get with cubic inches. Hey I can say it:

NOTHING BEATS CUBIC INCHES


There you go you old schoolers- that one was for you!

 

[engineermike]

Not the freakishly extreme options you have with the 7.3. That is what you get with cubic inches...!

A pair of dohc heads would work wonders for it and any other 2v engine. See ls7 vs sb4. But nobody is going to do that...

 

[Fatguy]

A pair of dohc heads would work wonders for it and any other 2v engine. See ls7 vs sb4. But nobody is going to do that...

But you could...


Well I’m running out of battery and I’m training a guy in the 4 cylinder Amazon van. So...

 

[engineermike]

But you could..

Nobody is putting 4v heads on the 7.3. Mark my words. 400+ cid coyote...well that has been done....

Mush easier to add cubes to the 5.0 than 4v heads to the dump truck motor.

 

[Fatguy]

Nobody is putting 4v heads on the 7.3. Mark my words. 400+ cid coyote...well that has been done....

Mush easier to add cubes to the 5.0 than 4v heads to the dump truck motor.

A better argument for you is that you don’t need more motor than the limits of tire adhesion and the abilities of the driver (which is very low). After that weight, weight distribution, and economy become factors.

The problem is “the Fatguy factor” where what he wants defies logic but makes some sense to a very narrow niche market. That is where the math and engineering arguments fall down. The dude talks about visceral feelings under his foot at low rpms - have fun with that argument.

 

[GT Pony]

Yes but torque ultimately defines the limit of a car’s horsepower potential. The 7.3 has more
displacement and thus more base torque and horsepower potential than the 5.0.

Actually, what defines a normally aspirated motor's HP limit is the highest product of the torque times RPM (ie, again, it's the HP equation). Engines that make high HP make it in the upper RPM range because they can maintain good volumetric efficiency (VE) up high in the RPM range.

There are plenty of engines that make lots of torque, but don't make a lot of HP because they: 1) lose lots of VE in the upper RPM range, and/or 2) don't rev very high. Examples are diesel engines that have insane torque, but only rev to 2000 RPM max. They might have 700 ft-lbs of torque, but only put out 250 HP.

The Coyote makes lots of HP because it has good VE at high RPM, and it revs high. The only way the 7.3L could make more HP than it will in stock form would be to make it breath better at higher RPM (increase the VE) and/or make it rev higher, which probably isn't a viable option.

 

[Fatguy]

Actually, what defines a normally aspirated motor's HP limit is the highest product of the torque times RPM (ie, again, it's the HP equation). Engines that make high HP make it in the upper RPM range because they can maintain good volumetric efficiency (VE) up high in the RPM range.

There are plenty of engines that make lots of torque, but don't make a lot of HP because they: 1) lose lots of VE in the upper RPM range, and/or 2) don't rev very high. Examples are diesel engines that have insane torque, but only rev to 2000 RPM max. They might have 700 ft-lbs of torque, but only put out 250 HP.

The Coyote makes lots of HP because it have good VE at high RPM, and it revs high. The only way the 7.3L could make more HP than it will out of the factory would be to make it breath better at higher RPM (increase the VE) and/or make it rev higher, which probably isn't a viable option.

Right, and here is where it gets interesting. How good is the flow in those heads? Beat the old motor by ten percent and you have beaten the Coyote:


“What if the numbers could be even better? What if Ford is able to get a 10% improvement in flow with the 7.3L? This will push the 7.3L V8 estimates to: 482 hp and 557 lb-ft of torque.”


Source: https://www.google.ca/amp/s/www.tfl...ew-7-3l-v8-make-over-506-lb-ft-of-torque/amp/


That is not outside the realm of possibility. The motor was envisioned in the Brian Wolfe era back in the day and even if it does not have a graphite impregnated iron block, that does not mean that it’s original design “DNA” has been changed along the way. Like it or not Erick427 may be right.


Only time will tell.

 

[GT Pony]

Only time will tell.

True, it's all speculation until the official numbers come out ... and unfortunately that probably means this bastardized thread will live for a very long time still.

 

[Fatguy]

True, it's all speculation until the official numbers come out ... and unfortunately that probably means this bastardized thread will live for a very long time still.

There is one odd thing.


Hotrod.com asked Ford about valve dimensions (obviously) and Ford would not give them the info. Now you may think they may be crappy, but Ford does not want to push the idea of this in a Mustang at all costs. So maybe the head flow is good! But we will find out shortly

 

[CrashOverride]

I'm sure it will be good - with bores that large it all but has to be. And the LS6 proves that 2V can be "quite good" but geometry (And that evil math thing) dictate that a proper 4V head will have more valve area per cylinder which more or less translates into cfm.

What makes an engine "good"? BSFC. The most efficient air pump wins if you ask me.

 

[engineermike]

The problem is “the Fatguy factor” where what he wants defies logic but makes some sense to a very narrow niche market. That is where the math and engineering arguments fall down. The dude talks about visceral feelings under his foot at low rpms - have fun with that argument.

You once again waded into a technical discussion you are clearly not equipped to have...then when you realize you’re on the losing side you then switch back to “I want visceral....logic doesn’t matter” mode. This appears to be your modus operandi....when losing, switch to feelings because people can’t use math, logic or engineering to prove you do or don’t feel a certain way.

For the 10th time, if your justification is purely emotional, then stop trying to make the technical case because you are clearly not well-suited for that discussion.

 

[Erik427]

Actually, what defines a normally aspirated motor's HP limit is the highest product of the torque times RPM (ie, again, it's the HP equation). Engines that make high HP make it in the upper RPM range because they can maintain good volumetric efficiency (VE) up high in the RPM range.

There are plenty of engines that make lots of torque, but don't make a lot of HP because they: 1) lose lots of VE in the upper RPM range, and/or 2) don't rev very high. Examples are diesel engines that have insane torque, but only rev to 2000 RPM max. They might have 700 ft-lbs of torque, but only put out 250 HP.

The Coyote makes lots of HP because it has good VE at high RPM, and it revs high. The only way the 7.3L could make more HP than it will in stock form would be to make it breath better at higher RPM (increase the VE) and/or make it rev higher, which probably isn't a viable option.

You really need to look how big the ports and valves are when it comes to the 7.3
That huge nine cam bearing tunnel is designed like that for a reason.
That is a feature normally only found on high rpm pushrod applications.
The amount of bearings and the size of that cam tunnel are very telling.

By the way.......the best Ford has offered from the Coyote platform is 8,000rpm.
The rod to stroke ratio is very poor due to the very low deck height.

 

[GT Pony]

By the way.......the best Ford has offered from the Coyote platform is 8,000rpm.
The rod to stroke ratio is very poor due to the very low deck height.

What other factory stock 5.0L V8s with a power train warranty are designed to rev to 8,000 RPM.

 

[Erik427]

Putting 4 valve heads on a SBF or LS chevy is quite easy.
Mercury marine offers the LS in such a configuration.
You can even do it to a sbc.......

As for a 400 cid Coyote?
Deck plates to increase the deck height.
Custom aftermarket billet crank (No Other Is Offered).
New timing cover.
Resleeved block.
Custom timing chain.
Custom intake or adapters to make a 5.0 intake work.
Rods
Pistons
Cams

Seriously?

Or a 400 cid MMR all billet motor could be ordered.....

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