24 replies to this topic

[desmo]

If this doesn't make interesting reading for you, you may be in the wrong forum ;)

Comparison Between V12 and W12 F1 Engines

It's a big pdf file but it's worth it. Lots to talk about.

[kos]

Just super.

[Bluehair]

Great stuff!! I'm sure it's been discussed, but would a W-9 be within the rules? Or maybe if the center bank was a 4 cylinder, a W-10 would be possible.

[BRG]

Has anyone made a W12 that really worked? Ignoring the Life fiasco, I know that VW are flirting with the idea. If it is a feasible option, with weight and CG advantages, why has it not been tried seriously?

[marion5drsn]

W-12 engines were made by the British company Napier and were called the Lion an engine of excellent repute! These engines had a B & S of 5.5” x 5.125” (139.69mm x 130.17mm) 1,4461.6 cu. In. (23.9L) they were used from about 1919 to about 1932. They were numbered from Lion I to XV. Holding world records in 19225 and 1929. Alec Lumsdens book, “British Piston Aero Engines”, has four pages devoted to this engine.
M.L. Anderson

[desmo]

OT: I would like to put this article on my hardrive rather than having to download it every time I'd like to have a look. My usual "Save" "Save this Page" or "Save As" from my File pull-down menu are not functional for pdfs. How do I save it to my hard drive?

[scarbs]

Go over the link, right mouse click and save target as....

The theory of a W format engines seems to be gathering alot of creedance in the forums recently, the graphic describing the frontal layout of engine gives me a headache how do you neatly package that lot...? Exhaust pipes running next to induction stacks, lots of heat transfer, where would the exhausts blow out of the sidepods, as a designer I love symetry, the W12 makes my nose bleed....!
Also would the layout not also give torsional problems such as have been rumoured with the renault 111V.

[jpf]

If I remember right, the article claims better torsional stiffness, probably because of increased cross sectional area and five bolt connection to the monocoque.

[leegle]

Scarbs you like symmetry? There was an Austin Healey record engine that had carburetors and exhausts out both sides of the head. Maybe you could do that with the centre bank and run the other two conventionally?;)
There is reason in this day and age for these engines to be considered in production applications. The need to keep engines short for transverse mounting with front wheel drive may lead some manufacturers to try them even if only for marketing advantages. "We offer triple overhead cams!"

[desmo]

Thanks scarbs, I should have figured that one out!

You've heard of quad cam engines? Introducing the sex cam! That should get a few peeking into the engine compartment.

[Keith Young]

Yeah- either looking at the engine or searching the web with the keyword of boobs. So far I've started loading the pic 3 times, and each time I gave up, lets see if I have the patience this time.

[Powersteer]

A five bank longitudinally mounted 10 cyliner engine with intakes and outlets arranged slighty like a transverce engine(intake forward, exaust reverse) would be interesting while having staggered five banks with thee forwards banks and two behind. Five banks would be arranged so compact like a VW engine while the ports are very steep angle and direct to be able to arrange engine bay area efficiently(if this makes sense). Banks are not entirely longitudal but slightly askew, maybe 20deg to have better port arrangement?


Okay, okay!! this is only a 1¢ not even a 2¢.

[rek]

Originally posted by BRG
Has anyone made a W12 that really worked? Ignoring the Life fiasco, I know that VW are flirting with the idea

I believe the VW "W12" is two of their VR6 engines "put together" (in a way similar to how two inline 4s are "put together" to make a V8)

[edit for these links:]
http://www.ukcar.com...gine/vr/w12.htm
http://www.fortuneci...e_packaging.htm

[jdowns]

I don't know enough about F1 engines to say anything on that article besides 'Wow!', but a few things in it (in general, not just V12 vs W12 specific) caught my imagination.

I took some of their figures and modeled a single piston / crank pin in Derive (mathmatical software), and got some results for force and acceleration that stunned me.

@ 18,000 rpm, 41mm stroke, 96mm conn rod length, 290gram pistons, 277g conn rods, 11.3Kg crank shaft:

• I got the same mean piston speed (24.1 m/s), but the maximum speed is much higer, at 38.6 m/s @ +/- 78 degrees of TDC.
• Fot the crank pins, centrifugal force (my lecturer would get upset here, as it doesn't actually exist), assuming 1/8th of the mass of the crank is in each crank pins (they don't say in the document, but 11.3kg crank and 4 crank pins...), would result in the crank pins weighing 10.5 tonnes (1.4kg @ 7,400 g's, 23,000 lbs) each. I assume the counter weight would weigh the same. This is a constant force per crank pin.
• Maximum piston acceleration is over 8,600 g's at TDC!!!! (5,600 at BDC)
• reciprocating mass = piston mass + 1/3 conn rod mass = 382g (0.84lb). @ 8,600g's = 3.3 tonne! (7,200 lb). This is per cylinder! This is the weight at TDC, it 'only' weighs 2.1 tonne @ BDC, so there is a total weight transfer of 5.4 tonne (12,000lb), 18,000 TIMES PER SECOND!.

These figures may be old news for the old hats, but for an engineering novice, I'm pretty impressed that these engines hold together at all! I've a new found respect for F1 engineers (it was pretty high before).

None of this is specific to a W12, I just used the engines in the articles for masses, stroke, conn rod lenghts, etc..

Oh, yeah, these are just figures for a free spinning engine. Add the forces due to compression and combustion strokes....

[Croaky]

Interesting stuff. Pity they outlawed 12 cylinder engines. Does anyone know much about radial engines? If you're going to have lots of banks of cylinders, why not put them in a lovely circle?

[Spunout]

OT - The new Bugatti sports/luxury vehicle will have W18 engine (driveable prototype was recently tested in Finnish car magazine). Too bad the price, which will make Ferrari´s look cheap, will mean it´s unlikely I will ever see it live.

[Engineguy]

The simplistic idea of "more is better" is seldom all it's cracked up to be. That applies to cylinders, cylinder banks, or 5000 lb. sports?/luxury vehicles. The benefits of more usually are at some point overwhelmed by the detriments it causes in another area. There are many disadvantages that the W12 paper's authors ignored or dismissed lightly. The chances of ever seeing a W engine in F1 are about the same as the chances of Minardi winning the constructers championship THIS year. While Bugatti may get away with this nonsense with the gold chain crowd, they don't have to worry about a 107% rule.

[Top Fuel F1]

Originally posted by desmo
OT: I would like to put this article on my hardrive rather than having to download it every time I'd like to have a look.

desmo:

I am curious about how long it takes you to down load and open this PDF? On this T1 connection it's taking me about 20 sec. In any event something like this I usually print out for easier reading.

Rgds;

[desmo]

I'm on a dial-up, so when I am downloading a file like this I will go get a cup of coffee or check the mail or whatnot and when I get back it'll be done. Whether it takes 20 seconds or four or five minutes isn't too important to me.

The authors of the paper, Mattarelli and Marchetti are heavyweights in the field. I'm not convinced the idea (a W12 F1 engine) doesn't have real merit. It seems to me that the packaging issues are the most daunting.

"For the V12, the angle between the banks is 75 degrees,
One drawback of the W12 is the position of the exhaust
manifolds of the central bank, which are very close to the
intake telescopic tapers and can be disturbing for the
snorkel design. However, the amount of heat transferred
from exhaust to intake gas should be quite easy to limit."

This is perhaps at least a trifle optimistic. Of couse, it seems likely we'll never know as the FIA has pretty much killed any innovations of this significance.

I was more interested in the stuff on V10 cranks, the detail of the working drawing of the crank throws, the stuff like component weights and dimensions.

[rdrcr]

Pretty awesome article desmo...

While W12 engines have been proven, some questions I have are, engine hp relative to its weight, and c.g., (seems like a fair amount of mass up top). The VWW12 is the closest to being turnkey I understand. And given the complexity of the valvetrain and cams, I'd be pretty impressed that these engine would twist as high as they do and last.

I'll have to copy this one into my library as well...

It's a shame the FIA just doesn't go with a fixed liter rule and open configuration. F1 is supposed to be about the exploration and implementation of automotive technologies exercised in motorsport.
Ideas on engine configuration and design would flourish.

Regards -

Richard


P.S. Bet you can hardly wait for cable...

[Bluehair]

The rules state: Must have 10 cylinders, must be circular, 5 valves per cylinder is the max, and 3000cc is the max. It looks to me that a W-10 with 4 cylinders in the middle and 3 on each side, is perfectly legal. It may not be the way to go, but I think it would pass as legal. What would really be cool, is 2 of those Honda V5's (scaled up to 1500cc's each) put together in the shape of an X!

I agree with rdrcr, that the FIA needs to allow more flexibility with the configurations and number of cylinders. I'm still sore about
Toyota's V12 being disallowed.

[leegle]

I am no genius when it comes to engines but it seams to me that two banks of three and one of four would be very hard to balance. There would also be a larger number of problems to affect the bank with the most cylinders. What about a V8 with just two additional cylinders in the middle then to form a W10? You will then have the engine shortened by the same amount and more room in the middle for equipment and also the plumbing and the two additional cylinders can be balanced by placing them on opposite throws of the crank. I can see this but maybe marion5drsn or engineguy can correct me.

[jdowns]

One of the major bennefits quoted in the article is the lowering of CoM, but what would happen if you took all the plumbing into account? F1 blocks are Al, no? You may be lowering the CoM of the Al block, but did they take into account the extra head, the extra pair of camshafts (mounted vertically above the engine, where they're at +/- 35 degrees in a V engine), extra headers, and extra heat sheilds? That stuff's all steel (except for the heads), and it's all up top, so I wonder what the net result in CoM would be in a real engine?

I've heard that several production cars (Ferraris, Porsches) have 'horizontally opposed' engines, could someone explain why they can't be adapted to F1? If you're after a low CoM, that'd have to be the optimum. Why all this excitment over 115 degrees, why not go 180?

[moog101]

diffusers, exhaust routes, side pods, the necessity to have a large central structure (currently the airbox) to comply with the rules, and the need for seperate intakes despite the latter.

It's been discussed, so search for the thread (as I am much too lazy to do so for you )

[MRC]

Interesting read. Was anyone else disturbed by a 1.07 safety factor? Sounds a bit insane, even for an F1 engine. I'm assuming that the longer W12 crank pin journals have higher bending moments. It seems like for a fair comparison, the W12 crankshaft should have the same safety factor as the V12 cranksahft. A larger diameter crankpin would be in order, which would increase friction, and make the W12 have even more friction than stated. This would make the W12 crank heavier than projected also. I also don't quite get why they use a different method for drilling the oil passages in the W12 crank.