OMC 3 Cyl expansion Chambers
I am currently in the proccess of building a 3cyl 920cc omc to run pipes.
Has anyone done this? I have had the side of the block milled and welded up to fit flanges. Obviously plugged where the exhaust used to exit so the cooling water doesnt escape down there.
What is everyones comments on expansion chambers over pure megaphones?
I will build a set of megaphones purely to run it at night and get some footage of her thrown flames out!
Everything else has been done to it. 19s fron half. Finger ported, head work etc etc. The never ending quest for more speed has brought me to exhaust work.
Look to todays 3 Holer racing sleds for technology leads.
These days you see faster changes in technology in the 2 stroke racing snowmobile arena in North America then anywhere else.
You do see many 3 Holers with 3 pipes (but they are fully supported in sled bodies and platforms) but you also see many sled 3 Holers with a single pulse tunned manifold coupled to a single expansion chamber as the system used. Their horsepower is very bizarre.
Such a single pulse tuned 3 cylinder coupling exhaust manifold coupled to its design expansion chamber would be a practical route for a OMC 3 Holer to increase horseower yet instead of the pulse tunned manifold and dump pipe you see commonly now or the Lopez unit of a decade ago. Too many pipes you have breakage too boot where a single design expansion chamber and pulse tune manifold is a happy medium between that and pulse tune manifold with dump pipe. What will racers do? Study snowmo racing information sites and think about it.
Thing is you add more horsepower and another prop what do you do with the raceboat technology to handle significan increases in horsepower?