Going to port my own heads. Which OE Evo heads should I use?

[phelan]

Actually it's for my dad's bike, but anyway. No doubt Evos had some funky combustion chambers over the years. Should I look for some early sandcast heads with the oval bathtub chambers, some "D" chamber heads, or should I use the hemis? I really don't like the performance of the hemi chambers, but are the ports better enough to consider them?

[prodrag1320]

think twice,ive had alot of people over the years bring heads into me to try to "fix" the home porting jobs after the lost HP/torque.we`ve been porting heads for over 25 years,and myself (and 99% of other reputable head porters)will tell you,its not as easy as it may look,it takes years of experience and many different port contures to get the expected results.one of my customers is the top cardio vascular surgeons in the area,i dont do open heart surgury,and he dosnt do his head porting.if your dead set on doing it,rule #1 is bigger isnt always better(the combustion chamber wont have any effect on port flow either,the difference there is combustion turbulance)feel free to call me,ide be more than happy to give you a couple pointers
kirby
vee twin racing
(812)876-0155

[EZE RIDER]

Good looking out Kirby.

[phelan]

Thanks, not my first time around the block. I'm not gonna do any major porting, mostly polishing more than anything. Satin finish on the intake ports and mirror on the exhaust. Most of the 'porting' I speak of is just around the seats to clean up flow. I'm leaning towards the 'D' heads because of their availability, unless the hemis have way better ports. I'm working on an economy build and trying to get decent performance for next to nothing. High comp forged pistons, self port/polished heads, bored/honed stock cyls, high lift springs, clearanced rockerboxes, Andrews E27 cam. Just looking to get some decent performance. Still trying to talk my dad into running a 2-1 instead of his V&H longshots.

[prodrag1320]

didnt mean anything,cleaning up the overhang on the seat is a real good start.on a mild port job,the most important area is a 1/2 above and below the actual valve seat,air will find its way down a hole,getting the air around the valve with out messing up the flow (eddying or stagnating the flow) is the tricky part,the valve job itself is critical.seen alot of decent port jobs messed up with a crappy valve job!!pay attention to the short side (floor) of the port,like i said,air will find its way thru a hole,but on the floor of the port,you must fool the air to make the curve around the bottom of the port,try to round it smoothly with no sharp angles.now try not to laugh to hard,but water acts alot like air,and back in the day before most folks knew what i flowbench was,we used water ran thru the port,you want the water to come out on the combustion side uniformly and not dumping out the long side (roof or back of port).you wont get CFM #`s,but it will let you know if your doing OK
kirby
vee twin racing

[phelan]

No worries, I've done a lot of research on this over the years and comPletely agree with your first statement lol. I was just sayin' that while I'm new to this forum, I'm not new to forums or Harleys . I appreciate all of your advise Kirby. I'll probably hit you up on the tele when I finally get the heads I decide on and start working.