The rare and powerful Volvo B7xxx engine

[BlackBart]

A high schooler could photoshop that…..
How many servers did that take?

[volvolugnut]

I had employees that followed instructions like that...........
volvolugnut

[Sveedy]

It seems like the AI app doesn't understand how an engine works. At least in the first picture there are 7 holes in the side of the block
I wonder what it would show for an " inline 5 cylinder " for reference ?

[erikv11]

I guess I'll try again tomorrow at 2:49 pm.


7cyl.png

With the AI knowing damn well that 7^2 = 49

toying with us

[abscate]

sigh


sigh.jpg

The fact that it didn’t include Daisy will always make its lack of life apparent.

I’m still scared by the anecdote of the person who asked AI if it were a bot, and it knew to lie about it.

[BlackBart]

"I'm sorry Dave, I'm afraid I can't do that."

[matthew1]

Back to the 7-cylinder AI Challenge™!

As before, the only instruction to each AI was this: draw a line art of an inline 7 cylinder engine block. It must show seven cylinder bores, no pistons, and the cylinder bores must be inline

Well folks, I don't think we're getting better, and might even be getting worse. I ran this again today and here are the results:



ChatGPT


My comment: no comment... if you don't have anything nice to say, etc.

Grok 2

My comment: Grok 2 completely failed the "line art" clause in the instructions, even though these renderings are pretty neat looking.

image.jpg (141.82 KiB) Viewed 1641 times

image-2.jpg (229.17 KiB) Viewed 1641 times

image-3.jpg (138.55 KiB) Viewed 1641 times

My Thoughts

The fourth Grok 2 image is not a mistake, the AI really did fail like this. I included the screenshot since there was no downloadable. ChatGPT image files are .webp, which are very, very awkward files because image uploaders typically reject them as images. Why does ChatGPT make this the downloadable file type? Whatever.

An interesting discovery is that the impossible nature of a 7-cylinder engine as a true, real-world engine is not responsible for these terrible AI images. How do I know? I tested this theory by simply swapping the 7 for an 8 in my command.

But wait! What's that in the upper left? A SEVEN CYLINDER INLINE ENGINE BLOCK.


Final Thoughts

Despite the hoopla, AI image generation is not even in the ballpark. It's certainly interesting, but that's about it. It's not useful in a technical setting, and IMHO not even useful as a grade school educational tool at this point. I'll test again in a few months.

[BlackBart]

The GROC 2 has some very curious exhaust ports....

[matthew1]

ChatGPT's looks like a 1980s boom box on LSD.

Oops, I guess I did have something not nice to say.

[matthew1]

Aaaaaaaaand we're back with another episode of "Draw That 7-Cylinder Engine Challenge".

But before the results, a note from our sponsor author: When I started this series in 2024 I thought it would be a good challenge, mostly because I had mistakenly (*see below) thought that because no automobile engine has ever had seven cylinders, that they were more or less impossibilities. Not so much design or production impossibilities, but that they were at the very least, market impossibilities, if for no other reason than 360° ÷ 7 equals a non-whole number.

That, I thought, would compound the difficultly, but after a couple years I don't know that it has. IF it has, it's because there aren't many/any examples of 7-cylinder engines out there for these AIs to reach down into the well to retrieve/conceptualize/output... i.e.: it's not because of the mechanical difficulty in designing a 7-cylinder engine, which I had thought would be the primary bottleneck. It's the lack of examples that exist out there on the Web... a much duller and less exciting explanation.


Chat GPT

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Grok

7cyl-grok-1.jpg (96.96 KiB) Viewed 957 times

Summary

We're getting there. Chat GPT's is spot-on. Grok's is unintentionally very funny, because I'm assuming it thinks the additional two cylinders (there are five on deck) will work positioned from both longitudinal positions

Notice both systems have abandoned the flourish and detail we saw earlier in this experiment that looked almost like a 19th Century inventor's sketches, or maybe something from Da Vinci's notebook. The newer images are clean and decidedly non-frivolous.





* From Chat GPT


Is a 7-cylinder engine possible?

A 7-cylinder engine is not a design impossibility—it can absolutely run—but how well it runs depends heavily on the configuration.

---

Where 7 cylinders work well

• Radial engines (aircraft) commonly use odd numbers like 5, 7, or 9 cylinders
• A 7-cylinder radial runs very smoothly due to even firing intervals
• Power strokes are evenly spaced (about 102.9° apart in a 4-stroke cycle), which helps balance

---

Inline 7-cylinder (your design)

This configuration is much more challenging.

1. Firing balance

• A 4-stroke engine cycle takes 720°
• 720 ÷ 7 ≈ 102.86° between firings
• This means it can fire evenly, so it will run

2. Engine balance

• Inline engines rely on symmetry
• Inline-6 engines are perfectly balanced
• An inline-7 breaks symmetry, leading to:
  • Unbalanced reciprocating forces
  • End-to-end rocking vibration

3. Practical drawbacks

• Very long crankshaft → more flex and torsional vibration
• More complex crankshaft design
• Rougher operation than inline-6
• Packaging is inefficient (engine is long)

---

So would it run?

Yes—but:

• It would likely feel rougher or “lumpy”
• Would require balance shafts or heavy counterweights
• Engineers usually choose better-balanced layouts instead

---

Real-world examples

• 7-cylinder radial engines: common historically
• 7-cylinder inline engines: extremely rare, mostly experimental

---

Bottom line

A 7-cylinder inline engine is mechanically feasible, but not ideal.
It would run, but compared to conventional designs, it would be:

• Less smooth
• Harder to balance
• Generally not worth the tradeoffs

---

If you want, I can also lay out the crankshaft phasing—that’s where things get especially interesting.