With Volkswagen and Fiat having petrol and diesel twins waiting in the wings, what advantages and disadvantages are likely over the `normal` 4 cylinders?
I had a twin in a Fiat 126 (best not remembered) and a flat twin in a 2CV, but these new engines seem in a different league re power and economy.
What about torque from two cylinders though? and what sort of design can we expect re cam drives and injectors in the Diesels?
I must say, I find the proposition a `breath of fresh air`in basis engine configuration,for city cars, but with a clean slate, no excuses for design inadequacy.
Well, I`m assuming they are something totally new, to get the power and economy. But are they going to be fussy over stretched, and shimmed `bike` engines needing a lot of attention?
regards
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BMW have been fiddling with twin cylinders as well ( well only for the last 80 years), what they've ended up with is a set of very sophisticated boxer twin, jam packed with sophisticated technology its fast frugal and torquey. With the weight of their bikes I guess it should power a car well enough !
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I personally think they should address the weight of the cars rather than develop more efficient engines, looking into researching and innovating car designs that meet safety standards yet lighter.
Whilst I appreciate the safety standards and equipment have forced the weight up, 1.5tons+ for a Mondeo is awful in terms of the amount of raw resources in use along with the effects it would have on the engine's economy pressing on.
Reducing the weight overall combined with the current generation of efficient engines in itself would make a major impact. The BMW Mini diesel based on the 1.6HDi engine that many many cars use themselves, is easily capable of 70mpg+ on the combined cycle and very close to the 100g/km threshold, too. Its not even as small as the C1 either.
Edited by smokescreen on 26/04/2008 at 21:56
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Should be very sophisticated. Fiat is tlaking about 70 bhp from a 900cc parallel twin. This is going to be tubocharged and should be brisk, characterful and very economical. I get bored with four pot drone so this should be interesting and shouldn't be rough because it will run a balancer shaft. My best mate had a Fiat 126 as a first car and that was very noisy and raucous, air cooled of course (the very last 126 Bis was water cooled)if a plug fouled with only the twin pots you were in trouble as it could only just crack 70 on two. If you can't wait for these and like a bit of character try a Citroen C1 with its little three pot. That is a nice little engine and from memory the valve train is twin cam 12 valve and operated by chain.
The 2CY is a flat twin and that engine being a boxer actually gets sweeter the more you revi it as it is perfectly balanced. I like small cars and these should be very interesting. Forget the doom mongers the future is going to lie in smaller and yet more powerful and efficient engines. Look at the VW Twincharge 170 BHP from a 1.4!
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Personally I can't wait for modern twins. Everything in their favour from volumetric efficiency through lightness and compactness to cheapness of manufacture, they have everything going for them. Make a nice chuffing noise too with luck, none of that foursome drone...
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Just done a bit more research. The Fiat engne looks great check out fiat.co.uk and go to about Fiat and follow the technology link. I was wrong about the figures. The engine is called the "Mulitair" and is a 900 cc parallel twin. It is fitted to the Fiat Panda Aria concept and the figures are an amazing 105 bhp(better than the current hot Panda which runs a 1.4 16v) in trbo guise or 65 bhp in atmo.
Bring it on as this looks fantastic! should see it in the 500 first just do a Google on Fiat Multiair. Don't know much of the VW car but this engine is nearing production.
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P.S Those figures are running on a methane mix the boggo petrol is 80 bhp.
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Time to bring back the 3-wheel Morgan with its JAP V-twin?
Two cylinders and a big flywheel (a la 2CV) can be smooth and entertaining - I'm all in favour.
Edited by J Bonington Jagworth on 28/04/2008 at 12:14
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Lovely burble from the 2cv. I had three, 425cc (the best of three), 602cc and Ami 6, 602cc. The last had a saloon body and the engine could cope with 4 adults, so long as they were not in a hurry: 0-60 in all of them took about a week .
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Panhards rock, although selling them in the US back in the 50s and 60s where even 6 cylinders were for poor people was a bit tricky.....
Generally v-twins in bikes are engineered for pretty decent torque compared to inline fours. The pure Engineer in my head says that anything more than about 700cc is a bit big for 2 cylinders but I'm all for variety in cars so I'm looking forward to seeing them.
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The Yamaha R1 has 107 N/m against the Ducati 999's 111 N/m torque - so pretty equal on max torque - as you would expect from similar capacity - but a rider on the Ducati perhaps has better access to the torque and so feels that the bike pulls better. The R1 has a more peaky power band which gives a higher max BHP.
I would agree with your view that 700cc is a bit big for two cylinders - but it appears that cylinder sizes are increasing - Triumph are planning a parallel twin of about 1700 cc - possibly more. My Yamaha TDM is a parallel twin of 900cc and balancer shafts - this gives about 88 BHP, but don't expect it to pull below about 2500 RPM.
Are Fiat going for 360 degree cranks ? - ie even spaced firing intervals - but very poor balance, both pistons go up/down together; or 180/540 degree - where pistons are travelling in opposite directions. The Yamaha uses a 315/405 degree crank to give it the same firing arrangement as a 90degree V (L-twin to Ducati) which balances reasonably well with the balancer shafts and gives good torque delivery.
Those big pistons take some starting - especially with a motorcycle battery.
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The big advantage on a bike is that the reduction in the number of firing pulses per revolution on a twin compared with a four, are said to give the rear tyre an easier time when riding on the limit. Plus of course, they produce their torque at lower revs as SteVee says.
If this Fiat has a Termignoni option, I'm buying one! ;-)
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hi DP , didnt the big honda fours of the 70s use the spare spark system with a double open ended coil pack thus halving the "pulse" per rev ?
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The big advantage on a bike is that the reduction in the number of firing pulses per revolution on a twin compared with a four are said to give the rear tyre an easier time when riding on the limit. >>
If you really want to smooth out your firing pulses, you need a dual mass flywheel ;-) now there's a whole can of worms!
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"700cc is a bit big for two cylinders"
350cc per cylinder? Pah!
www.motorcyclistonline.com/roadtests/2004_kawasaki...l
:-)
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Panhards rock
You can say that again Garethj... Don't suppose many here remember the fifties Dyna Panhard, but it could cruise at 80 and with its bench seats and steering column gearchange was effectively a six-seater for normal-sized people if they didn't mind close proximity. The engine being about a litre wasn't super-smooth, but the thing went extremely well and was economical. Only the French could have come up with it.
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The Panhard Dyna is fiendishly clever, but my heart belongs to the 24CT. C is for Coupe and T stands for Tigre (Tiger). An early one with finned drum brakes showing through the centre of the wheels.
*drool*
You might even get where you're going, with luck. But reliability is overated
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Panhard et Levassor was one of the earliest motor manufacturers, and the Dyna (later PL17) and CT 24 were the last of the line before being subsumed into Citroen.
The engine capacity was 850 cc (same as the original Mini) and with 40 bhp pulling a car the size of a Ford Cortina performance can't have been brisk - let alone seating six....
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Ever been in one Avant? A bit crowded with six, but they could fit. And the thing could cruise at 80. The engine felt a bit lumpy compared to a 2CV, but then it had much more poke.
The CT models were even faster, but they weren't as nice or as nice looking and perhaps there were better cars at the same price that could do 90... they weren't super cheap in fact.
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I thought the Tigre was 60bhp? And even though the body might have been as big as a Cortina it's quite light - the bonnet and front wings were in 1 piece like a Triumph Herald and the bootlid and top of the rear wings were similar.
But you're right, they weren't too sprightly on winding UK roads, they responded much better to fast French roads where you could rely on good aerodynamics and stability to keep your speed up. And they were very expensive in the UK so despite some enthusiastic road tests at the time, sales here were dreadful.
Still, the world is a better place for their existance ;-)
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The real headline statistic for the FIAT Multair is the emissions, or lack of them - 69gmC02/km. Goodnight Prius.
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Time for a single cylinder I think. Perhaps diesel with a hot bulb. Progress?
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Progress yes, the FIAT engine may be a twin but is very sophisticated and is not only powerful for its size but promises to be very clean. I thnink the immediate future is going to be highly efficient yet downsized engines. Look at the VW 1.4 TSI and Fiat's own 1.4 turbo that puts out 150 bhp.
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