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Dratted TINYURL is not working but if you do a Youtube search on Honda Z600 Coupe you will find a couple of good clips of this little cars twin running. I think it is very sweet for a twin.
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It is due from the start of next year as far as I know. They are investing 400m euro now to expand the polish factory where it will be made.
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Fiat are asking an awful lot from a 900cc twin. My Yamaha TDM has a 900cc twin producing about 88BHP, with an 8000 red line. It's a fine engine, but unsuitable for a car, IMO.
I get about 60MPG - but the bike is ridden much faster than a car would be
It has counter balance shafts and a 270 deg crank, so is reasonably smooth, but twins can be difficult to turbocharge, so I would think 100BHP is unrealistic (supercharge might be more effective).
I know Ducati get a great deal more power from the 'L' twins - but you really wouldn't want their servicing costs !
A low power 900cc twin might be useful though (in a car) !
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Isn't the proposed Fiat unit a side-by-side twin rather than a 2CV or BMW bike flat twin?
Those used to vibrate in Triumph bikes at high rpm. But I can't wait to see and hear this Fiat thing with its turbo, vibration or no.
What, by the way, is the reference above to the valve actuation system? One assumes the engine is a four-stroke. Nothing problematic about camshafts is there (except in Vauxhall Corsas that is)?
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Solenoid operated valves, Lud
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>>What, by the way, is the reference above to the valve actuation system?
Rejoices in the name "Multi-air".
www.fiat.co.uk/Content/?id=10857
fourth and fifth paragraphs.
I suspect that it will effectively be changing between Otto and Atkinson cycles:
en.wikipedia.org/wiki/Otto_cycle#The_Otto_cycle
en.wikipedia.org/wiki/Atkinson_cycle
depending on load.
I'm sure there will be somebody along soon who knows what they're talking about....
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From the description in the Fiat link, it's a variable valve opening system operated by altering the pressure or volume of oil in the hydraulic tappets. I don't think the valves are operated by solenoids. Something closely connected to them may be though.
As far as I can see it varies the amount they open, but not the timing as such.
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>>As far as I can see it varies the amount they open, but not the timing as such.
I suspect the trick is how dynamic the change can be, as they are talking about "multi-lift" (presumably per cycle) as well as early and late, that's a whole new can of worms, beyond anything you could do with conventional variable valve timing.
I'm looking forward to it with interest - hopefully it will put the skids under some of the smaller diesels.
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beyond anything you could do with conventional variable valve timing.
I thought this too. Variable aperture worked by a device to hold the hydraulic tappets down a bit, thus reducing the aperture when the valves are open, simply can't be instantaneous in operation without causing damage.
Come on Fiat, publish a diagram (schematic if necessary)...
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>>Come on Fiat, publish a diagram (schematic if necessary)...
www.youtube.com/watch?v=5IrPcmMHqHE
youtube is really quite disturbing...
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Many years ago a neighbour had a little Z600 Honda micro car and I remember that as a very "zingy" little engine: ot rough at all: do a Youtube search and have a listen.
My very first car when I was a teenager was a Honda N360. Yes, an even smaller lump than the N/Z600! We got the car for £0 and it was a restoration project for me to hone my engineerings skills as a teenager. The engine needed new pistons, amongst other things ...
But yes, it was a very sweet engine once rebuilt and smoother than a 2CV.
If the OP is missing the character of a twin in the new Fiat 500, the bst I can suggest is the 3-pot AygoC107. Very characterful and willing!
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Big fan of the little Toyota unit as well as the Vw triple especially in 80bhp TDI form but I like others look forward to this little engine!
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The Honda N360 may have been a twin, but I am puzzled by the reference to the Honda Z600, perhaps meaning the S600 which as I remember it had a four-cylinder engine, certainly ohc and perhaps twin-cam, with FOUR CARBURETTORS, one for each cylinder, oh joy!
As well as this jewel-like engine the Honda, a small two-seat sports tourer, had its differential and rear axle ahead of the rear axle line, with drive from the ends of the axle to the rear wheels by chains. The (solidly constructed, obviously) chain cases were the trailing arms on which the rear wheels were suspended. One wondered slightly whether the Honda engineers had been boning up on Frazer Nash history and updating it.
I don't know how well they wore but there are still a few S600s around. Charming devices (in principle). Indeed that was the car that made me realise Japanese automobile engineering had emerged from the copycat-with-grotesque-styling era and was no longer to be sneezed at.
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>>The Honda N360 may have been a twin, but I am puzzled by the reference to the Honda Z600, perhaps meaning the S600 which as I remember it had a four-cylinder engine <<
You should do some homework then as the Z600 was indeed powered by a 599cc 2cyl OHC producing 32 bhp.
The S600 was powered by a 606cc 4 cyl DOHC producing 57 bhp.
Ill put my anorak away now :-)
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Ah. Thank you stu... I hadn't registered the Z600.
Actually I can see why from the figures, although of course 32bhp is pretty good by early 2cv standards...
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Another fact, perhaps relevant today, is that Motor magazine managed to get 136 mpg out of one at 30 mph. I wonder if 35 years on there are many cars that can do that? Gotta laugh!
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>>Motor magazine managed to get 136 mpg out of one at 30 mph.
Yes, in order to provide decent acceleration, internal combustion engines on cars are massively oversized for modest cruising requirements, and operating the engines at such low loads ruins their economy.
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Actually I used to own a Honda Z600 with the parallel air cooled twin and for the UK market this engine produced 45bhp on low octane fuel (2 star). It was a wonderful little engine capable of cruising at 75mph plus on full throttle and easy to maintain. What is interesting is that this engine 40years ago produced the equivalent of 75bhp per litre and the new Fiat engine in NA mode produces 74bhp per litre so why are people raving about new technology when that's zero progress in that time. I admit Honda were technically advanced for their time although the cars were not a huge success then, but it was early days for the japanese makers.
The Motor magazine at the time did indeed have to fiddle their mpg figures after recording astonishing results first time out. The only technological advance I can see with the new Fiat engines is with the turbo models to boost power, although this will surely affect economy.
The S600 sports (4cyl water cooled) was never officially sold in the UK. I also own a very early S800 (10th car made) originally owned by Honda UK and used for press release, but that is a different beast altogether.
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Thats an interesting post.
I never knew the Honda Z600 existed until your post.
A good read on wikipedia soon solved any questions.
did they seel well here in the UK ?
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Wasn't the Z600 the stumpy little car, that had the rear leaf springs protruding through the rear valance? There were a few about in the 60's as I recall. In fact my cousin hired one for his honeymoon in Devon. He was pleasantly surprised how well it went up the infamous Porlock hill!
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Well it is here. Autocar have tested it. And their touring mpg was an incredible 42mpg.
So all that technology has simply gone into getting amazing mpg for the official figures and zero road tax.
I hope FIAT are ashamed of themselves.
Edited by Glaikit Wee Scunner {P} on 08/12/2010 at 19:32
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mention of the Citroen 2CV reminded me not of its engine but its suspension. A friend of mine had one and occasionally took four of us to North Wales for hillwalking. That little car could take rough tracks in its stride and it wasn't a 4 wheel drive.
I
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Looking at the video (earlier link) I would say that the solenoids used to control the valve opening are probably pilot operated (similar tech to CR injection solenoids).
Pilot operated hydraulics at that scale and speed involve incredibly small dimensions - bad news as far as tolerance to contamination is concerned.
One thing for sure, better change the oil and filter on time otherwise you will be hit with a CR size maintenance bill.
Edited by brum on 10/12/2010 at 00:24
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While 3-cylinder engines look set to have a bright future - with Ford, BMW and Mercedes developing them for the next Focus, 3-series and C-Class respectively, I can't see the 2-cylinder engine becoming popular in anything except microcars. VW were planning a 2-cylinder engine for the forthcoming Up! car, but now it's going to have a 3. VW did a 0.8 TDI 2-cylinder that was used in some economy prototypes but that's been dropped, i think.
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With the current (sensible) trend for lightly blown petrol engines to give good economy and power when required, it makes sense to switch to three cylinder engines which give perfectly even exhaust pulses enabling the turbo to spool up more quickly. Other than pure cost saving (machining only required on two planes) I've no idea why so manufacturers have stuck with 4 cylinders for their small engines. Daihatsu got it right 30 years ago. Triples make far, far more sense in these applications.
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Plenty of companies make 3cylinder engines,Mitsubishi,GM,Mercedes,Fiat,Daihatsu,Suzuki to name a few.Ilikethe one that is fitted in the the Smart forfour and Mitsubishi colt cracking little chain cam engine.
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