A tale of two headers

Eyeball (Hi-Ball) engineering strikes again. Here is a pic of the two modified PS100o headers Dad and I tacked together to creat my very unique exhaust treatment. Someday I might plump for a real custom set, with a single pipe and racy bends, but for now, this will work. They were tig-welded by the guys at Cycleboys, and I have put a coat of cheap hi-temp paint on them. The final step will be wrapping them in header wrap (black, again) to keep some heat off the rear shock, and perhaps my right boot.


Anyhoo, with a multi-cyclinder bike, there seems to be several ways to plumb out spent exhaust gasses -- a 4 banger might have a 4-2-2, a 4-2-1, and a 4-1; a triple might have a 3-1, or even a 3-collector-3 for style points (think new triumph speed triple); twins can be a few different configurations as well. My EX 500 was a 2-2, with a crossover under the engine; the Muzzy race pipe was a 2-1; stock Ducatis are primarily 2-2, with a bizarre, restrictive-looking X-piece underneath the rear of the engine. Ducati superbikes sacrificed some power for the sake of style and less drag with their then-radical underseat exhaust. Harleys (don't laugh) are one of the few large-displacement twins with separate headers per cylinder, with no crossover. They seem to make it work by focusing on keeping the header length the same, or as close to it as possible. Easy on a 60 degree cruiser with the turning radius of the Titanic; less so with a sportbike with a 90 degree L-twin. The route to the rear of the bike is far shorter with the rear cylinder.


My eyeball engineering has come up with this:

• now modified, the header diameter is the same for both cylinders



• the foward cylinder header is now 5.5" longer than the rear (before it was 9+" longer)



• guesstimation states that the two bends in the shorter rear header is equivalent to adding length the the rear header... theoretically bringing the total length of each closer to the same

Fact? No clue. Before my ears started to bleed, the thing would at least idle with the straight-through pipes. Eagerly awaiting the parts to finish the cherry bomb specials (my cans) and the prefabricated ones I purchased. They are seen below on the original owners' SC1000.