Who will swap for the new 7.3 V8!

[BmacIL]

he bigger question is whether Ford already has an actual Godzilla mule on the road.

The answer is no.

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[King K. Fool]

I've seen some V6 owners come up with some pretty serious excuses, but this is just off the charts. Haven't lost this many brain cells while reading through a forum thread since the "I just ran the hose water through my Cobra block and now it won't start" days.

I just can't wrap my head around this nightmare of a project when there are running/driving classics with big block pushrod motors about 3 clicks away on Craigslist.

 

[engineermike]

The big V8s could handle the three speed and later 4 speed autos. That is the smooth, quiet but high torque motors needed for that application.

Why can’t you seem to understand that the current (and likely since 2011) 5.0 makes more torque ACROSS THE BOARD than those old big blocks?

Ford is stuck with the A10 now so those are the breaks......

Hahahahaha.....you say that like it’s a bad thing....the a10 is awesome!

 

[Fatguy]

Why can’t you seem to understand that the current (and likely since 2011) 5.0 makes more torque ACROSS THE BOARD than those old big blocks!

We don’t have any numbers on the 7.3. My Fox body made like almost 300 foot pounds of torque from the 80s. Ford didn’t design a new engine with 1950s specs. They will be better than the older engines. We shall just have to wait and see.


But the comparative principles should hold true. You will get more torque out of the 7.3 than the 5.0 as that’s the engine’s reason for being. Maybe 475 at 1,200 rpm...


By comparison...


The Volvo D13 can make almost 2000 pound feet of torque at around 1,200rpm but the quote peak torque at 1,000 is at almost 1,500 pound feet of torque. 1,000 rpm is what they like to quote - even less than my 1,200.


The recommended rpm operating range is between 1250-1500 so that is perfect for me and probably 80 percent of Mustang owners! Of course this is a diesel.

 

[Dusten]

We don’t have any numbers on the 7.3. My Fox body made like almost 300 foot pounds of torque from the 80s. Ford didn’t design a new engine with 1950s specs. They will be better than the older engines. We shall just have to wait and see.


But the comparative principles should hold true. You will get more torque out of the 7.3 than the 5.0 as that’s the engine’s reason for being. Maybe 475 at 1,200 rpm...

It'll never happen. The damn 7.3 psd doesn't make that much, that low. Hell my 2018 6.7 barely makes that power. A fucking gasser won't.

 

[Fatguy]

It'll never happen. The damn 7.3 psd doesn't make that much, that low. Hell my 2018 6.7 barely makes that power. A fucking gasser won't.

Maybe, but give new tech in an old design a chance...

 

[martinjlm]

So, the original question was “Who will swap for the new 7.3L V8?” Five pages in it seems like the answer is “nobody”. Or am I missing something?

 

[Fatguy]

So, the original question was “Who will swap for the 7.3L?” Five pages in it seems like the answer is “nobody”. Or am I missing something?

No you’re right, only me. It’s depressing...

 

[Dusten]

Maybe but give new tech in an old design a chance...

Explain what new tech? Its not direct injection. The heads aren't a ground breaking design. Iron block, steel crank, cam in block, no distributor...

It'll make 450/525 and I bet peak torque is around 2500rpm

 

[engineermike]

But the comparative principles should hold true. You will get more torque out of the 7.3 than the 5.0 as that’s the engine’s reason for being. Maybe 475 at 1,200 rpm...!

Torque is a function of cid, VE, and compression ratio. The cid is obvious, but there is no chance a 2-valve large cid engine will have the VE of the 4-valve 5.0. As for compression ratio, the coyote is 12/1, only made possible by gdi. The 7.3 does not have gdi and, therefore, will likely not have 12/1 compression. Don’t be surprised if the new 7.3 doesn’t have as proportionally more torque than the 5.0. For instance, the current 5.0 makes 22% more torque/cid than the current 6.2.

 

[engineermike]

.... Ford didn’t design a new engine with 1950s specs. They will be better than the older engines.....

You went on and on about how awesome the old big blocks were. When you (finally?) realized the current 5.0 is better, you’ve switched to saying the new 7.3 will be better than those old 1950’s v8’s.

The Volvo D13 can make almost 2000 pound feet of torque at around 1,200rpm but the quote peak torque at 1,000 is at almost 1,500 pound feet of torque. 1,000 rpm is what they like to quote - even less than my 1200.

Industrial gas engines make even more torque at even lower rpm. One of my favorites was 10,500 ftlb at 350 rpm. Do I want it in my mustang? Heck no!

My money says the 7.3 will make 505 ftlb at 4000 rpm and 450 hp at 5500. Not having gdi, high compression, or tivct really narrows up the rpm range. Sorry.

 

[BmacIL]

We don’t have any numbers on the 7.3. My Fox body made like almost 300 foot pounds of torque from the 80s. Ford didn’t design a new engine with 1950s specs. They will be better than the older engines. We shall just have to wait and see.


But the comparative principles should hold true. You will get more torque out of the 7.3 than the 5.0 as that’s the engine’s reason for being. Maybe 475 at 1,200 rpm...


By comparison...


The Volvo D13 can make almost 2000 pound feet of torque at around 1,200rpm but the quote peak torque at 1,000 is at almost 1,500 pound feet of torque. 1,000 rpm is what they like to quote - even less than my 1,200.


The recommended rpm operating range is between 1250-1500 so that is perfect for me and probably 80 percent of Mustang owners! Of course this is a diesel.

So, I currently work in the heavy truck industry. There are many reasons a big I6 13L like what you drive makes peak torque that low. The first is they're tuned for that because 80k GCWR. Big engines can't rev high because of the mass of the reciprocating components. The cams are designed for under 2100 rpm operation. The turbocharger (many of which are VGT these days) is sized for big torque just a few hundred rpm off idle. The right tool for the job....

FYI big bore, on-highway diesels migrating to OHC.

 

[Fatguy]

You went on and on about how awesome the old big blocks were. When you (finally?) realized the current 5.0 is better, you’ve switched to saying the new 7.3 will be better than those old 1950’s v8’s.

No I always wanted a new one otherwise I would
have purchased an old one. If I could get a minty one cheap that would be different - but good luck with that! When I got old enough to get interested in cars those old “legends” were rusting hulks. Rust around the scoops and rusty wheels...

I gave up...

Despite all the negativity, I’m still curious to see the first versions of this swap and see how it’s received...

 

[Fatguy]

Shit, 1850 ft-lb at 1000rpm, sign me up. Let's change the thread name to "Who's swapping to a 12.8L turbo-diesel that weighs 2800lbs?".

Ever raced any heavy trucks from a stop light unloaded? Faster than you think. Every time I close the door on a trucker he says he’s going to report me. But his telemetrics would show him flooring it for 15 seconds and try explaining that away!

 

[CrashOverride]

1. The older-than-me dude in the first video is awesome. Totally the kind of guy that has stories on top of stories and is a tinker-er like me. It would be awesome to sit on the porch while drinking some beer or lemonade and talking shop. He's the grandpa I hope to be.
2. I'm not going to judge anything - I like any time one tries something new. Sometimes they go against conventional thinking, sometimes they fail, and sometimes they are amazing. I'm sure when people suggested going from one cam and 16 valves to four cams and 32 valves, people were probably shocked and thought it wouldn't be worth it because of cost, complexity, and non-linear flow gains. But it worked. Then they tried a 5-valve, and it worked, but not as good. Then they tried a 6 valve, which was basically pointless.
3. I find the 7.3 very interesting. The chevy guys have got to be going nuts over it about how Ford finally "saw the light". It is definitely an about-face for Ford, but in some ways, a good idea. Any time you build an engine with big cylinders and a tall deck, you're making a smart decision (To a degree, of course). Look how Ford screwed themselves with the 100mm bore spacing they imposed on the Mod motor back in the 90's. They have had to stroke the engine considerably, rev the snot out of it, and plasma coat the cylinders to keep up with the new LT1. If, instead of a 100mm bore spacing they went with something larger, then you could build a much varied engine size. Keep the pistons big, but offer different strokes. Trucks get a long stroke for more torque, and 2V/SOHC cheap valvetrain because no need to rev a truck engine over 5-6000. Then, have a smaller stroke engine that you can rev the snot out of, make good low end torque, but killer mid-band torque. The geometry of oversquare engines is superior because of larger valves, reduced side loading, increased dwell, decreased piston acceleration, etc... The other thing that people are forgetting is that variable valve timing is definitely possible on OHV engines. Mechadyne reportedly developed a solution for Dodge with the Viper Gen5 engine, that allowed independant curves on the intake and exhaust. Essentially a cam-in-a-cam. Complex? Yeah, works? Definitely. Works as good as if you went with 4v/4cam? No. Heck no. Can't beat the flow. Maybe....Maybe...Maybe (With a snarky smile) Ford is using this as a beta test. Throw a "dumb" engine in a truck, see how it does, then re-cast in aluminum (With some tweaks) and run different engines from there. The absolute best thing Ford could do to the Coyote would be to increase bore distance and increase the cylinder size. Even if they didn't want to change the deck height - those two things would make them way more competitive and future-proof against power gains from Chevy and Mopar.

* Note, Although I'm sounding like a OHV fanboy on point #3, I'm not. I have a Coyote because I love the Coyote. There are many different ways to measure what engine is "best" (Arguably, I say it should be BSFC, but most people don't know what the heck it is, so I digress). I'm very impressed with Ford has been able to do with the poor decisions made almost 25 years ago.

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