Getting everything ready to change my 96 to 103.Will mild port work and larger valves help a lot or will it move th HP to the higher RPM range?Its a touring bike Ultra and I want the HP and torque in the low RPM range.Thanks

 

A lot here will tell you the headwork will make a big difference.
From the before and after dyno sheets I've seen, I'd have to say there is little difference below 5K.

That being said, I would go ahead and do it just for S&G's.

 

Just recently had a thread titled "guess the hp/torque". Harleytuner had many interesting post about port/polish headwork and what to expect.

 

I'm not an expert, but every dyno I've seen the HP peaks toward the end of the scale, I believe Torque is what you are looking for, the cam seems to have an awful lot to do as to when that happens. Search the threads and call Dragos, Fuel Moto, and others, plenty of free and informative information.

 

From what I've seen on dyno charts and from personal experience porting and larger valves when used in conjunction with the proper cam will usually increase the torque somewhat. What they really do is extend the range the torque is maintained which is what gives you an increase in horsepower. If you look at the FM 555 charts in which the builds are all basically the same you will see that with head work there is a slight increase in torque, but a big increase in HP. If all you are looking for is low end then the head work may not be worth the money to you.

 

I guess everything depends on budget, unless your in congress. Plenty of options out there,(103,107,113,117). Only do it once. Are you doing your own wrenching?

 

I had Jamie do the Woods 6-6 cams in my bike and dyno it before and afterwards. (I also have the Stage 1). From completely stock to my current set-up I gained 25 Pound feet of torque and about the same in HP, and I don't need to be in the higher rpm's to have the torque available. You could port your heads, that's up to you and will most likely help your situation, just don't know if it's necessary for what you're looking for. Your cam is the biggest determining factor in where and how much torque you want.

 

If you and your head porter talk about what your goals are, he can set up your heads for the power band you want to ride in. Porting for velocity will generally help torque production at the lower end. Running bigger valves will increase capacity, but will generally shift the bias towards the upper end. If your porter has a one-size-fits-all approach to head porting, you need to find another machine shop.

 

Need much more information on the build. Specfically what compression you are going to be at and what cam you are going to run. It all needs to work together. Can't just throw parts together.

Zach

 

The build will be a 103 w SE255 cams and what I want is low end torque and horpower, not topend.Thanks