Exhaust for kawasaki 27hp

[LiveWire]

The garden tractor pullers around me are running stepped exhausts. That is their version of making them a megaphone. I made up a set up pipes for my father's. I started with 1 3/4 tube, bent it first then cut a wedge out to take it down to 1 1/8 ID at the flange. I spot migged the seem and ground it down. A 2:1 would probably make better power on it by scavenging, but it was kind of tricky building what I did. It did make a noticeable improvement in his pulling distance over the 2:1 ram's horn manifold that was on it.

My father is 82 and runs in the 13-20 HP 'Stock' class. The class is based on the stock rated horsepower of the engine. Stock got mutated to mean a stock engine of any sort, not just the engine that was in it. The Wisconsin TJD in my father's are commonly used on generator's and such. It has a massive displacement compared to engines of similar horsepower ratings. It is rated at 18.5 HP at 3200, but is rated very little below that all the way down to 2000. His spins probably 5500-6000 with a billet steel flywheel so it won't blow apart and rip his feet off, something to think about when taking the governor off an industrial engine with a cast iron flywheel.

[bdkw1]

Originally Posted by LiveWire

A 2:1 would probably make better power on it by scavenging,

Since it's a V twin and the cylinders do not fire 180* apart, scavanging isn't all that great.

[LiveWire]

Originally Posted by bdkw1

Since it's a V twin and the cylinders do not fire 180* apart, scavanging isn't all that great.

My father's tractor does fire the cylinders 180 apart. Well, 180 then 540. The older Wisconsin THD was an even fire. The later TJD was odd fire and makes more power at higher RPMs. The even fire has to shove a massive amount of air out of the crank case then suck it back in. The odd fire just moves it back and forth between the two cylinders. Many V-Twins have the rods on the same crank journal making them odd fires.