Engine porting
- Thread starter Zacattack
- Start date
Triples make power but its all in the topend. You kinda loose all bottom with them. Sorry to thread jack...
but since we're on the subject, and you think TRIPLES are the shizzle,
explain their pro's and cons for those of us who don't know ????
Alright, to add a little information to this rodeo. I sent all this to blasty_95 via PM earlier but I didn't realize that it was so much confusion involving the subject.
The first fact is, a single oval shaped exhaust port is NOT optimal for exhaust flow. You cannot make it but so wide before it will chew through rings and you can't make it but so tall before you have an unusable razor thin powerband.
There are a few methods to get around this issue. Suzuki used two triangular exhaust ports but this had the disadvantage of having a thin "bridge" between the two triangular ports that would overheat if not properly treated before installation.
One simple way is to take a cylinder with a large oval shaped exhaust port and add two smaller ports on each side.
This has the effect of increasing port area (if you don't make the triples above the main exhaust port and don't raise the main exhaust port) which means there is more area for blowdown. This DOES NOT reduce bottom end torque significantly but it does allow the engine to "breath" at higher rpms.
The trick is, while most people are going through the trouble to bore holes into the sleeve, they raise the exhaust port and change the angle of the transfer ports. Coupled with a "top end" pipe, this raises the onset of the powerband but greatly augments it....
The first fact is, a single oval shaped exhaust port is NOT optimal for exhaust flow. You cannot make it but so wide before it will chew through rings and you can't make it but so tall before you have an unusable razor thin powerband.
There are a few methods to get around this issue. Suzuki used two triangular exhaust ports but this had the disadvantage of having a thin "bridge" between the two triangular ports that would overheat if not properly treated before installation.
One simple way is to take a cylinder with a large oval shaped exhaust port and add two smaller ports on each side.
This has the effect of increasing port area (if you don't make the triples above the main exhaust port and don't raise the main exhaust port) which means there is more area for blowdown. This DOES NOT reduce bottom end torque significantly but it does allow the engine to "breath" at higher rpms.
The trick is, while most people are going through the trouble to bore holes into the sleeve, they raise the exhaust port and change the angle of the transfer ports. Coupled with a "top end" pipe, this raises the onset of the powerband but greatly augments it....
I have a stock bore jug sitting in my bedroom. Where do you think that one is going.
My house? Lol 15151
