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Sept 26, 2015 21:13:47 GMT
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May fall flat on its face, but could turn out to be an interesting thread. What oddball tech have manufacturers thrown out into the field, that either worked, or fell flat on its face. Preferably with pretty pictures and/or videos. The two I'm going to start with, is the Honda VTEC - essentially a "soft" cam, and a balls-out cam, that it swaps between, via the use of hydraulically operated locking pins: And the second - Rover VVC. Kinda like the Honda VTEC, but also nothing like it. Instead of a hard swap from one cam to another, it uses a weird arrangement of eccentric pulleys, and a split camshaft. At low revs, it just runs like a normal camshaft. Nothing particularly interesting. At higher revs, it starts to open the intake earlier, and close it later. Basically increasing the duration of the cam, in a smoooooth transition, from a minimum 220 degree (crank angle) to a maximum 295 degree. The camshaft however, is basically being shaken around like a baby on Jeremy Kyle. Constantly accelerating and decelerating. No simple gifs available I'm afraid, so have an assortment of pictures, and a quote: So come on, describe your favourite bit of odd tech.
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Last Edit: Sept 26, 2015 21:17:44 GMT by chairchild
You're like a crazy backyard genius!
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Sept 26, 2015 21:17:53 GMT
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I have Volkswagen diesel . Amazingly its emissions are supposed to be low but they used some management gizmo to do this and pass tests !
Fancy that !
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Sept 26, 2015 21:33:00 GMT
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I love Fish carburettors! All you need to tune it to your engine is a single (supplied) allen key. And the telescopig throttle return spring thing is also a genius invention!
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MrSpeedy
East Midlands
www.vintagediesels.co.uk
Posts: 4,789
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Sept 26, 2015 21:34:39 GMT
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We have an old paraffin engine dating from 1902.
It has three valves per cylinder (multi valve), roller cam followers and variable valve timing.
As they say, there's nothing new these days!
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Sept 26, 2015 23:51:31 GMT
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I love the simplicity of 'fish' carbs. I'm not sure if these fit here, but have a Commer/Rootes 2 stroke diesel. 3 cylinders, 3 injectors, 6 pistons, 1 supercharger, massive rocker shafts driving 1 crank. The main advantage being, having 3 injectors rather than 6, fuel consumption was low for the power output. Or if you want a 2 stroke diesel, but that lot ^^^^ is a bit dull, have a Napier diesel (which powered torpedo boats and the Deltic diesel-electric loco), many pistons and cylinders, 3 cranks...
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Sept 27, 2015 8:08:13 GMT
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Phwoar , big deseasel engine porn .
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Sept 27, 2015 11:34:42 GMT
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how does that v tec lock up at speed without things breaking ?
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91 golf g60, 89 golf 16v , 88 polo breadvan
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Sept 27, 2015 12:23:38 GMT
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how does that v tec lock up at speed without things breaking ? I've always wondered how they UNlock under load personally - as surely the pin would be almost wedged in position? The answer: very clever engineers, and no doubt some DAMNED hard steel!
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You're like a crazy backyard genius!
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Sept 27, 2015 12:25:52 GMT
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yeah i just cant get my head round the timing and workings of a pin shooting out to lock it up at that speed
clever stuff
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91 golf g60, 89 golf 16v , 88 polo breadvan
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adam73bgt
Club Retro Rides Member
Posts: 4,950
Club RR Member Number: 58
Member is Online
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Funky engine techadam73bgt
@adam73bgt
Club Retro Rides Member 58
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Sept 28, 2015 7:53:00 GMT
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One I remember while looking up stuff at uni, is the Lancia Triflux engine which was deisgned for their proposed Group S rally car the Lancia ECV They came up with a novel way of simplifying the process of twin turbocharging a 4 cylinder engine, by 'splitting' the exhaust valves across the cylinder head, half go out each side rather than having a hot and cold side as in a conventional crossflow head the intake charge is combined and comes in from the top of the engine Certainly worth having a read about as its a neat idea www.ecv1.com/e-motore.htmAnd the car it was to go in is pretty awesome too, shame Group S never got a chance after the tragedies in Group B
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Sept 28, 2015 8:22:15 GMT
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Napier surely made the most interesting engines I've ever seen... the Deltic as above, the H-24 configured Sabre and this mad thing: The Nomad, a hybrid 2-stroke flat-12 diesel with a turbine strapped to the bottom. The turbine supplied boost pressure to the piston engine and both were connected to the output shaft through gears. It was supposed to be an efficient alternative to the turbojet (which it probably was).
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I've got Rovers.
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Sept 28, 2015 9:10:36 GMT
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Exhaust pulse charging is something I would never had thought of. I think I understand it but it's difficult to explain... There's a body of chambers arranged so they rotate in a cylinder driven by the crank. One end of the chambers are connected to the air intake (atmosphere), the other to the exhaust. The chambers are open to atmosphere and exhaust at different times, governed by the rotation of the chambers and how the holes line up. The 'charging' element comes from the higher pressure exhaust compressing the inlet air and from pressure waves bouncing from one end of the chambers to the other, creating a vacuum at the inlet end when the chamber is open to atmosphere and high pressure at the inlet end when it's open to the engine inlet.
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I've got Rovers.
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Sept 28, 2015 11:06:54 GMT
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Nissan Ecology Oriented Variable Valve Lift and Timing or neo vvl engines The sr20ve between 97 - 2001 made 187bhp and 2001 onwards in the primera made 204bhp They also did the sr16ve n1 in the Pulsar vz-r n1 limited to 500 cars sold in Japan and made 197bhp These don't have turbos fitted but the sr20ve head is a good swap onto the sr20det motor to get a good power increase
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Sept 29, 2015 14:35:13 GMT
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While googling a bit more about how the VTEC engages and disengages perfectly, I found this: www.import-car.com/tech-feature-the-variables-of-valve-timing/Which led me to the other end of the technological innovation scale, the GM Cadillac L62 engine with cylinder deactivation, which they marketed as variable displacement. Now totally technically achievable and not a terrible idea but at the time it was just beyond the limits of the available technology.
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ToolsnTrack
Posted a lot
Homebrew Raconteur
Posts: 4,121
Club RR Member Number: 134
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Funky engine techToolsnTrack
@overdrive
Club Retro Rides Member 134
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Nov 24, 2015 15:07:30 GMT
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I always appreciated Ducati's method of eliminating valve float on high RPM engines....
Remove the valve spring altogether.. Simple but effective.
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Nov 24, 2015 17:27:58 GMT
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While googling a bit more about how the VTEC engages and disengages perfectly, I found this: www.import-car.com/tech-feature-the-variables-of-valve-timing/Which led me to the other end of the technological innovation scale, the GM Cadillac L62 engine with cylinder deactivation, which they marketed as variable displacement. Now totally technically achievable and not a terrible idea but at the time it was just beyond the limits of the available technology. I remember reading about those, all the fuel economy of a V8 and the power of a 4 cylinder.....no wait thats not a step forwards
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froggy
Posted a lot
Posts: 1,099
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Nov 24, 2015 17:45:27 GMT
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Can't seem to find any pics but Saab did a 1500cc 4 pot with a supercharger and a tilting mechanism to alter compression ratio from 14-1 down to 8-1
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Nov 24, 2015 18:49:05 GMT
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I suppose this might be the right place to ask this. I never understood why some racing engines (do they still do it?) had the exhaust and intake reversed- The exhausts in the middle of the V and intake on the outside. What was the advantage to that? This sort of thing. I've also noticed this one seems to have the fuel injection stacks between the camshafts.
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Nov 24, 2015 19:33:02 GMT
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Compressed air motors have always interested me since i had a little single cylinder air powered motor in a model plane.Suprising nothing has ever made it into large scale production in a way.It would be interesting to see how the government would find a way of taxing air !
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Nov 24, 2015 20:12:33 GMT
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