Scout Power

SCOUT POWER

CW TEST

2015 INDIAN SCOUT

Indian's new liquid-cooled V-twin gives us what we want

Kevin Cameron

Indian’s new 1,133cc Scout is based upon the concept of the original Scout of 1920, which was an American sporting middleweight. To learn more,

I spoke with Product Director Gary Gray and engineers Matt Frank (program lead), Wayne Kolden (development lead), Dean Jagielo (hardware development), and Blaine Kaeser (hardware design).

“Our Indian Chief showed that we love and understand the brand,”

Cray said. “It is the Indian heritage, brought forward. Through it, we’ve earned the right to decide where to go next.

“The original Scout was created to draw in new riders who wanted a lighter, easier-to-ride motorcycle,” Cray continued. “Our new Scout has the same purpose, so it’s easy to ride even for those new to motorcycling. It feels light and manageable when you pick it up off its sidestand.”

I looked at the engine’s torque curve, which is not a curve; it’s a nearly horizontal straight line, flat from 2,000 to 8,000, delivering 64 poundfeet nearly the whole time. “Powerful but not intimidating,” one of the engineers said, obviously proud of it.

Now get this: That high, constant, usable torque comes from a bigbore, short-stroke, liquid-cooled 60-degree V-twin. Remember, the original Scout was an American sporting middleweight, and it continued to win loyal owners (and races) from 1920 right through the postwar era. Everyone who has ridden the new Scout praises its strong, easy-to-use power. This engine actually has the flat torque curve that others talk about, and it does not sag as the engine revs up.

Looking at the heads in 3-D, you’d think they’d come off something from Ducati or Cosworth: D0HC, flat-topped pistons, narrow valve angle, and high-flowing downdraft ports. Why? Because every one of those features can make positive contributions no matter what kind of torque curve you want. Traditional long-stroke two-valve engines can be made to give strong bottom torque, but as they rev up, airflow falls behind demand, giving the traditional down-sloping torque and limited peak power.

You can clearly see, highlighted on the castings, the twin arcs of each head’s two cam drives. This is not a motorcycle on which non-traditional features are painted out with flat black. “The original Scout’s cases are tightly wrapped, revealing the authentic nature of what’s inside,” I was told. The same has been done with this new Scout.

Why double-overhead cams and four valves? Because with four light valves, you can combine the short valve timing that gives powerful bottom torque with the intake flow area necessary to keep that torque high all the way to redline. Part of the recipe is the 10.7:1 compression that boosts both torque and fuel efficiency. Air-cooled engines can’t take the heat of high compression for long, but with liquid-cooling it is business as usual. Like other modern engines, Scout has piston-cooling oil jets. There is a counterbalancer to civilize the engine’s natural shakingforces. This is modern technology in service to riders who want easy-to-ride power.

What is Scout’s power? It is 86 hp on our dyno and delivered in a smooth, straight line. Because of this, the rider can take as much or as little as he or she wants.

This shows us that the tools of modern engine design-four valves, double-overhead cam, short stroke, fuel injection-can be used for any purpose. Yes, we instinctively associate them with peaky sportbikes, but their versatility allows them to deliver whatever is desired. In the Scout’s case, this is constant torque that is always at the rider’s command.

When they tell us the 200-pound, 96.0 x 73.6mm engine has a “semidry-sump” lubrication system, that means oil is carried in a tank that is part of the crankcase but separate from the crank chamber. Intakes are in the vee of the cylinders with a single fuel injector in each port. Central spark plugs are fired by stick coils integrated into the spark-plug caps.

What does it all mean? This is another step, like Harley’s V-Rod, in setting the design of American motorcycles free from narrow tradition without loss of valued qualities. It can now take whatever direction American riders choose.