They are the engine used in the 2009 and 2010 BD Wolf, and I have read (somewhere) positive things, but have not seen a formal analysis of them, except for The S&S website, which I suspect of bias.....
. They are of course commercially available, and I'd love to know what the custom builders think of them.
In reading many rider comments, the only themes I noted were high levels of customer satisfaction with the engine. Jonathan is right--- there was a problem with timing belts failing in the 2009 (early production) engines. Turns out that happened mostly in the south and they figured out it was due to excessive heat. The belt simply got too hot and disassembled. Happily, the engine does not suffer damage from the valves striking the pistons--it just quits dead....So they installed a spacer (washer) in the camshaft timing belt cover mount bolts and that cooled it adequately. Replace the belt and install spacers (washers)--problem solved.
A few design differences:
It has a 56 degree design instead of our traditional V-twin 45 degrees.
It has three cams--one intake and two exhaust, run by a belt.
The combustion chamber is wedge shaped (hence the name x-wedge).
It has cast iron cylinder sleeves and round fins for more even heat transfer.
It has regular bearings instead of roller bearings, with a much heavier one piece crankshaft (smooths the idle).
It has 5 studs per cylinder as opposed to four, a significantly stronger design.
Most of the Wolfs (sp?) coming up for sale are low mileage, so I haven't seen much from guys who ride hard. Currently there is one in CA for sale with the most miles I've ever seen---20K. I'm seriously looking at buying one to tour with, and if I do, I'll let you know. And to be clear, I have no reservations about plunking down cash for a bike with that engine. It seems to be a well engineered, and addresses some of the issues created by making larger and larger V-twin engines.
