OK, question. If you walk up to someone and say, " I am getting headwork" done on my bike". To you, what work does that entail? If a guy tells you that he is getting some head work done, what do you assume he is talking about and getting done to his bike? Doesn't "headwork" include having them put on a flow bench? Is there "different" levels of what "head work" is or what can be done to them?

At times I feel like technology has passed me by a little quicker than even I thought it did or that I had realized it has. Comments by anyone who does this for a living or those who have actually had headwork done to their bike would be greatly appreciated. As soon as I can dig out in front of my garage and get to my bike and get it down to the shop things will happen fast so I'm thinking I need to bone up a little better on what head work means today rather than what it meant 20, 30 or 40 years ago!

 

It usually means getting the valves enlarged, having the ports cleaned of obstructions and radii smoothed and blended to promote more volume and velocity. Having the ports matched to the intake and exhaust manifolds, and the combustion chambers matched for volume as well. Not all porters use a flow bench and some will charge extra for the service.
Hope this helps. I'm sure someone with far more knowledge will chime in.

 

QC - that was good. Yes to different levels, can roughly run ~ $500 up to $1300. The cost will usually depend on how big you are going (hp/tq), and if you are trying to get every bit out of your heads possible.

 

having had a few done I can say the level of headwork relates to the size of the build, in particular cam size, higher lift and larger overlap cams require more flow so more porting/polishing and larger valves (intake mainly). matching ID ports is best w intake manifold and some shops CNC the work, some by hand (my preference since no 2 castings are ever alike 100%), some CNC then finish it by hand. If the build is a monster one, flow of high 280's cfm @28 is needed and some heads maybe cvo can see well over 300cfm. It all depends on how much air needs to be packed in chamber to maximize the builds potential. So the level of headwork is dependent on other variables.

Scott will surely chime in to correct me or add some better info.

 

This is a good thread for my question also.

Im sure most have seen my recent 107" build. I opted not to do the heads and I dynod at 109 hp / 122 torque. If I were to do headwork, wouldnt that pretty much just give me more hp (top end speed) but not necessarily give me more torque (seat of the pants feel)? That is my understanding but I want to make sure.

 

Talk to a porter. You can have your heads ported to increase low/mid range TQ or top end HP.

I saw your post the other day. A mild port job would probably net you a power increase across your entire RPM range

 

I had my heads done when I did mine over. They were ported to increase the speed/flow and cc the chambers. This increases the low/midrange power. If the heads are cnc ported or done by hand and increase the size of the runners and valves you will increase the topend more. In most cases the guy doing them will do the heads for the cams you are going with. An engine is a complete combination of all the parts. The heads are where all the power is made, the rest is just an airpump

 

From what I have understood, there are many different "levels" to headwork. All depends what you want out of it. I got lucky when i did the cams and had a good tuner just run with what he thought appropriate to reach the result i had in mind and fit in my budget. They were decked .036" and the ports cleaned up a bit for better flow. Not too invovled as far as headwork goes, but I ended up with better power than the big bore kit and for way less money.

 

I remember your past posts and based on your dyno chart I think headwork at ($1000) range would give u in the 120hp range (mostly 4500rpm plus area) and 5-6 tq thru the whole rpm range with a big difference in how far the tq carries out. That being said, the 2007 and up heads do flow fairly well stock and for your enjoyment purposes it may not be worth it labor wise to pull the heads off again and spend the cash. If u love it now I would stick there.

I personally like hitting the 5000rpm+ range at times burying the needle, so heads are worth it to me.

 

Cool. This confirms pretty much what I was told... that the 2007 up heads flowed pretty well, better than in years past. When we pulled them and looked, the openings on the intake are fairly pretty well open, not much left to port there. But with just another 5-6 torque and 120+ hp, I worry about the stock crank on my 07 holding up.

I am more of a "How fast can I get to 80 -100" kind of rider more than I am a "burying the needle" kind of one....althought I do enjoy the occasional "bury thr needle" when riding with friends out in the country.

So yea, I just dont feel like its worth another $1000 and another S300 for the dyno to do the headwork. I dont mind the work of pulling the heads, I love working on it. But who knows, in a few years I may end up doing it.