Damn, for a split second there I thought Ferrari was coming out with a V9 engine - which would be a very funky contraption indeed!
The reason there are so few four-door convertibles is that it's hard to make a folding roof that big - which explains the hefty price tag on this one. Also, torsional stiffness and side impact crash resistance are severely compromised when you chop off the B pillars.
Leapoard = Chinese pronunciation of Leopold, the German mechanic who folds down to fit neatly underneath the passenger seat.
Fracture splitting connrods is standard practice in the industry. Bearings are not split that way, instead half-cylinder shells are inserted after the splitting.
Otherwise, the only real innovation here is marrying a boxer config to diesel combustion. Subaru had to do that because all of its vehicles are designed around the boxer concept. There are definite advantages in terms of center of gravity, pedestrian crash safety and especially, engine vibrations.
However, it's also an expensive configuration: you need four camshafts and two timing chains for a DOHC layout vs. two camshafts plus one timing chain for an inline four.
@ Spasticteapot -
wood is a natural fiber composite. Individual fibers may break but transverse cracks don't propagate. The mechanical failure mechanism is delamination, either parallel to the fibers or between the layers in a plywood construction. The latter also avoids warping.
Solid wood members will also warp or delaminate if they dry out, if only because of the internal stresses that sets up.
Moreover, the joins between components tend to be weak spots, that's why master carpenters use techniques like mortice and tenon to avoid glue, nails and screws.
@doggiedaddy -
and you know this because...
And what was wrong with that tourniquet jack again? If you're too lazy / technically inept to change a tire the old-fashioned way, switch to run-flat tires.
Someone should paint an icon on the bridge for each truck or bus it has claimed, analogous to the markings they put on WW2 fighter planes and bombers.
Glad you're ok, get well soon. I'm not sure what type of protective clothing you were wearing, it certainly appears to have spared you extensive road rash in addition to your fracture.
Btw, clothing with integrated air cushions is on the market, as are big cruiser motorcycles with an air bag.
@ Adamskiy -
big rotaries are interesting, but really tiny ones even more so. Not for vehicle propulsion, obviously, but they just might replace the batteries in your laptop!
@ Mr. Evil, bigmp -
this *is* a diesel engine with uniflow scavenging using side ports instead of poppet valves for both intake and exhaust.
In the perspex model, the cylinder end with the single row of large cutouts represents the intake port, while the other with the two rows of small cutouts represents the exhaust. Note that the inner piston on cylinder #1 (on the left) handles the intake port there while the inner piston on cylinder #2 handles an exhaust port.
I can see no obvious reason why they decided against a fully symmetrical design, which would have positioned both exhaust ports close to the turbo.
Battery burning hydrogen = fuel cell. Something got lost in translation.
This thing looks like a forklift truck from a minimalist designer.
@ Andrewpetty -
large two-stroke marine diesels use the piston for to manage the intake port and hydraulically activated poppet valves for the exhaust.
This engine uses ports for both intake and exhaust. The oil film deposited by the piston at the exhaust port does get burnt, producing blue smoke and coking.
Golle Motor AG has suggested using special coatings (e.g. molybdenum sulfide) to avoid oil-based lubrication of opposed piston engines altogether, but such coatings are very expensive. They also greatly increase both friction and blow-by losses. The company's web site is in German.
@ anaxomander -
the gain comes from achieving a 2:1 stroke:diameter ratio without excessive piston speeds at high RPM. Also, uniflow scavenging is more efficient than other strategies for two stroke engines.
[home.arcor.de]
[www.propulsiontech.com]
[www.sae.org]
@ SRekaugh -
the long rods are always in tension, so there's no risk of buckling. Besides, diesel engines generally don't run at 6000 RPM - the fuel needs time to ignite.
This is a lightweight, perfectly balanced and efficient two-stroke diesel engine. Too bad it probably won't meet on-road automotive emissions, that small package and low center of gravity would be perfect for city bus applications.
The inner pistons actually use a partial rather than a full piston pin, this reduces lateral forces on the piston liner. It only works because the boost system always keeps the pressure in the combustion chambers above that in the crankcase.
Presumably because of the target application in military UAVs, the company has kept a number of important details private. In particular, thermal problems with the pistons had been the primary reason why R&D in opposed-piston engines was discontinued decades ago.
A few years ago, a small company in Germany developed a carbon-magnesium matrix composite for the pistons of an opposed piston engine intended for light aircraft. Video in German:
Why a V8 at all? A 3.0L V6 with a single VGT turbo and a six-speed AT would do nicely, especially if you shave some weight off the vehicle by using higher-strength steels.
The point of an entry-level commercial vehicle is utility and low cost of operations. The F150 is not a musclecar.
@ Buckster -
somewhere on Jalopnik.com, Balsy the five-point harness owl salutes you!
At least I think it's called saluting. Damn ESL...
@ racerx -
not weird at all. The 335i uses high-pressure spray-guided GDI to run stratified combustion in part load for the sake of fuel economy. The price for that is that the injector and spark plug need to be positioned very close to one another at a very precise angle, or you get soot like in a diesel. To make room for all that, the valves need to be a little smaller. Also, the main injection is very late (just before TDC) so there is very little time for evaporation and mixture formation. All of this limits maximum RPM and therefore, rated power. The turbos are relatively small, intended to provide torque boost at low RPM. In other words, the 335i engine is optimized for normal road use.
By contrast, the M3 is designed for maximum power density, i.e. a rev limit bounded only by the high expected life of the engine. That means optimizing the whole air intake system for minimum pressure loss (straight ports), the long valves for maximum throat section, the spark plug for minimum diameter and, the valve train for maximum stiffness - all without exposing any part of the cylinder head to excessive heat, which could lead to engine knock, a cracked block or leaking valves. A lot of work has to go into shaving weight off the pistons and connrods, not just to rev easily but also to protect the journal bearings. At high engine speeds, peak stresses in the cranktrain occur not during combustion but at the end of the exhaust stroke, due to inertial forces.
Also, you want fuel evaporation to begin as early as possible to maximize the density of the fresh charge - power is limited by the available oxygen. With GDI, the onset of evaporative cooling is delayed until after intake valve close. This allows the engineers to increase the compression ratio for greater thermodynamic efficiency. However, once you have to enrich the mixture to protect components such as the cylinder head and three-way catalyst, fuel economy is a moot point and extra compression heat is the last thing you want. Besides, GDI pumps operate at higher pressure, so there's more to go wrong and greater parasitic load. For all these reasons, racing engines continue to use port injection.
