Is Indian working on variable valve timing? Recently unearthed patent drawings seem to hint that we’ll see just that.
Motorcycle.com has discovered patent drawings that show Indian’s existing Thunderstroke 111, but with a variable valve timing system grafted onto the top end. The rest of the engine is basically the same, with pushrod-actuated two-valve heads. But now, there’s a cam phaser system that moves the intake cam to either advance or retard the valve timing.
Other variable valve timing systems on the market (BMW and Ducati) have variable valve timing on both the intake and exhaust side, which would have more impact on performance than Indian’s intake-only system.
However, Indian’s intake-only variable valve timing system would accomplish the most valuable goal of all: reduced tailpipe emissions.
With Euro5 emissions regulations just around the corner, motorcycle manufacturers all know they’ve got to get on board with the new anti-pollution measures, or lose their ability to sell bikes in European markets.
That’s especially hard for air-cooled motorcycles with large cylinders; those bikes tend to see their piston rings warp more, due to their increased circumference, making for more blow-by. This is why large air-cooled thumpers have already seen a steep decline, especially in Europe (Yamaha XT660Z, etc.).
Air-cooled V-twins like the Indian Thunderstroke-powered bikes also have large cylinders, and more of ’em, so it’s even more important to keep emissions down. Adding VVT to these bikes would allow Indian to keep this same basic design in play for years to come, saving money and staying with a proven design. It makes sense, and don’t be shocked if you see the same basic design come to Harley-Davidson’s big air-cooled cruisers soon as well.