Just look at this beauty....
http://www.bath.ac.uk/~ccsshb/12cyl/
Almost scary.
Tony

Funny you should mention this engine, I will have one of the 6 cylinder versions fitted to my Austin Seven next week.

Impressive stuff.

I wonder how they achieve 50% thermal efficiency when car engines only manage 25-30%?

With 50% efficiency the average small car would do 100 mpg quite easily.

Steve B

Imagine changing a piston while the engine is in situ in a ship rolling around in the Antarctic Ocean.


Derek

<< >>

In fairness this is what make humanity amazing, just look at that stuff.

Excellent.

Stunning

Someone should tell Big Jim McBob that there's any even bigger engine available for his Monster Truck.

Joe

It's just not enough.

Brian OReilly

I suspect the 50% efficiency might come from designing the engine to run at a specific speed, thereby removing complications involved with wider powerbands.
Tony

[This message was edited by Tony Lockhart on WEDNESDAY 05 November 2003 at 23:07.]

I understand VW are installing a smaller version in their next TDi...

quote:

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Originally posted by Tony Lockhart:
I suspect the 50% efficiency might come from dsigning the engine to run at a specific speed, thereby removing complications involved with wider powerbands.
Tony

---

Correct !

Brian OReilly

And then there's this.....

apparently 400mph

I wouldn't want to try going round a corner on that thing

quote:

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Originally posted by Brian OReilly:

quote:

---

Originally posted by Tony Lockhart:
I suspect the 50% efficiency might come from dsigning the engine to run at a specific speed, thereby removing complications involved with wider powerbands.
Tony

---

Correct !

Brian OReilly

---

Also, the power produced goes up with volume - length scale cubed, while most losses (friction and thermal) increase with length scale squared. So making each cylinder big also helps efficiency.

Simon

quote:

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Also, the power produced goes up with volume - length scale cubed, while most losses (friction and thermal) increase with length scale squared. So making each cylinder big also helps efficiency.

---

Sounds plausible. That's probably why then, that 6 cylinder car engines are thirstier than 4 cylinder ones of the same capacity?

Steve B

In my youth a cousin of mine was a chief mechanic on a ocean going Vessel. I visited the boat when it was ashore in Sweden. The engine was being serviced and I vividly remember how people was INSIDE the cylinders working on something.

I have also been sitting UNDER a huge supertanker, but that's another story.

JohanR

quote:

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Sounds plausible. That's probably why then, that 6 cylinder car engines are thirstier than 4 cylinder ones of the same capacity?

---

Not quite - the six has more surface area for the same swept volume, hence more heat loss and more internal friction. Theoretically the six cylinder offers a higher power output because the moving bits are lighter and therefore can rev higher, displacing more volume per unit time and thus developing more power.

This is the main reason F1 engineers settled on V10 engines as a balance between rather a V12 and a V8 for the present capacity limit.

Unfortunately the F1 engineers are now stuck with V10 by rule. There were rumours of 2 strokes and other variations but these have been sidelined under the "cost" cutting rules.
Perhaps not the top of motor racing engineering after all.

Howard

I think the fact that they are 'stuck' with the V10 for now means that the engines are at the very limit of what can be achieved with that configuration.
There are stories that engine capacity will be reduced soon together with number of cylinders. 2.5 litre V8s have been mentioned.
Tony

RE V10

My understanding was that for the shape of cylinder used 300cc was the optimal charge/discharge capacity, well that was the current theory in the 70s as i seem to remember it.

Stuart