Saturday, May 3, 2008

2008 SAE Show: Engineer-a-Palooza returns to Detroit's Cobo Hall. We've got highlights.

In a desperate attempt to find yet another unique show theme evoking engineeringdom's war on global warming, organizers arrived at "A Climate for Change." Four days of symposia, round-tables, and technical-paper presentations took place in Cobo's meeting rooms and stage areas helping to edify those tasked with delivering a 35-mpg CAFE fleet, clean diesel engines, and the lighter, cleaner, more profitable vehicles we'll all be driving in the years to come. Out on the show floor, the manufacturers and suppliers of parts and services showed off their latest wares. We've got highlights.

BMW Hydrogen 7 Monofuel
We almost didn't stop to look at this one, as the hydrogen-burning 7 Series vehicles have been in operation for years (anybody watch the pres-Oscars red-carpet arrivals?). Those Hydrogen 7s were all bi-fuel, running on hydrogen or gasoline to enable them to maneuver between the few widely spaced hydrogen filling stations equipped to refuel a BMW (their connection is different from those used most other fuel-cell and hydrogen combustion cars). Naturally, running on hydrogen alone allows the compression ratio, valve timing, etc. to be optimized, resulting in better power, greater hydrogen-operation range, etc. But while emissions are so low that Argonne National Labs had to help design equipment to measure them, they're not zero. Trace NOx and CO are formed -- some of which BMW attributes to the V-12 engine's cleaning up of hydrocarbons in the atmosphere.

Toyota Prius Plug-Ins -- A123 Hymotion & Toyota's Own
Not one but two separate booths were promoting plug-in Prius hybrids. Battery supplier A123 will soon begin marketing a kit that mounts beneath the trunk floor, displacing the spare tire. The 5kW-hour L5 lithium-ion battery pack adds 185 pounds and piggybacks onto Toyota's power electronics. Because of the way the Hybrid Synergy Drive system works, the engine must be used at certain vehicle speeds, and most regenerated energy goes back into the stock nickel-metal-hydride battery, but the plug-in battery gradually discharges, increasing the amount of time the car can operate at low speeds in electric mode. At $10,000 installed, expect a distant payoff horizon. Meanwhile, Toyota showed a plug-in Prius of its own, with few details. It adds a second 6.5-amp-hour NiMH battery pack, adding 70-some pounds and permitting seven miles of EV operation (on the US LA#4 cycle) at a top speed of 62 mph.

Scuderi Split Cycle Engine
We profiled this oddball engine a while back, but to refresh your memory, the idea is to segregate the intake and compression strokes from the power and exhaust strokes in two separate cylinders, allowing each to be optimized for its purpose. The team on hand at SAE claims to have conducted preliminary tests that indicate the valvetrain is exceeding computer predictions and that full load performance is approaching 38 percent efficiency, with part-load results just under 30 percent. The engine is proving highly resistant to knock (because the air spends less time in a hot cylinder), and by firing after top-dead-center, so the piston is moving away as the gasses expand, very little NOx forms. By the end of the year a 1.0-liter two-cylinder proof of concept prototype should be up and running.