raising exhaust port

[sheerider1026]

well i ported a set of cylinders i had laying around.. i opened the transfers just a tad and smoothed them up(they have a ruff finish for atomization) i also smoothed out the intake the same way openeing it just a tad. i got the exhaust ports nice and smoothed and also opened them up a tad.. what i am wondering is what effect will raising the exhaust port 1mm have?? i know it makes it pipey and takes away lowend.. but what effect would just raising it 1mm have??gonna trail ride and race some.. i have toomey t5's 19ccdomes. +5 timing, reeds, and a 2 into1 with a 35mm pwk

[andrew ballard]

well i ported a set of cylinders i had laying around.. i opened the transfers just a tad and smoothed them up(they have a ruff finish for atomization) i also smoothed out the intake the same way openeing it just a tad. i got the exhaust ports nice and smoothed and also opened them up a tad.. what i am wondering is what effect will raising the exhaust port 1mm have?? i know it makes it pipey and takes away lowend.. but what effect would just raising it 1mm have??gonna trail ride and race some.. i have toomey t5's 19ccdomes. +5 timing, reeds, and a 2 into1 with a 35mm pwk

i think it would be a great idea to do the exhaust port, go 3mm more than usual up your timing and i think you be happy with it, well thats what you have to do to bet me haha

[sheerider1026]

i think it would be a great idea to do the exhaust port, go 3mm more than usual up your timing and i think you be happy with it, well thats what you have to do to bet me haha

PUBLIC ANNOUNCEMENT!! LISTEN UP EVERYONE.. ANDREW BALLARD IS GAY!! LMFAO! oh yeah, and his shee is slow

[andrew ballard]

PUBLIC ANNOUNCEMENT!! LISTEN UP EVERYONE.. ANDREW BALLARD IS GAY!! LMFAO! oh yeah, and his shee is slow

ooo man that sfucked up man, i aint riding with you nomore thats real fucked up haha hey buley said to call him

[sheerider1026]

i called him, sarah answered the phone and said he was busy.. lmfao

[Snopczynski]

raising the exhaust port 1mm will drastically effect bottom and midrange power. That changes the exhaust duration alot. I would not move it at all if your riding trails. You need to read Bell's book before doing your own porting.

[sheerider1026]

i decided not to mess with the exhaust ports.. i did however slightly widen the tranfers to add some tourqe.. i did not widen them toward the exhaust port.. only towards the intake port.. nothing drastic.. i chamfered the ports and lightly honed the cylinders, the pistons have a little wobble, but i am going to put them on anywa just to see how they run before getting them bored..

[Snopczynski]

If you widened the window, now you have to widen the transfer tract all the way down to match it. It cant be bulged out at the end. You really should read bells book before you do this stuff. There is alot of ramping and shaping that has to be done in all the ports to direct the a/f charge into the cylinder properly.

[4stroker]

raising the exhaust port 1mm will drastically effect bottom and midrange power. That changes the exhaust duration alot. I would not move it at all if your riding trails.

 

lol, i totally and utterly disagree with this statement....

[Snopczynski]

stock duration on a banshee is 178-179 degrees depending on your deck tolerance and base gasket. raising it 1mm will bring it to about 184.5-185 degrees. Thats good for a motor that is about a 9k-9500 rpm peak horsepower motor. at 178 degrees, it should be setup for a decent power range that is centered to arounf 6500-7k rpm. Thats what I would want to run on the trails.