Flowing hemi heads ...

[Pierre]

I know many here love to bash HD, but when it comes to getting flow out of 2 valve hemi cylinder heads there's more work being done in the Harley world than anywhere this side of NASCAR.

 

I knew about "smaller can be better" (from moto man among others) when it comes to porting, but the additional related info on squish - or not to squish, is pretty interesting as well. Kevin Cameron did the interview and translates the black art in his usual erudite and understandable manner. Lot of interesting info IMHO.

 

http://cycledoctor.com/Articles/JET.htm

[TX REDNECK (R.I.P.)]

In this business, patents give less protection than just staying ahead with a steady flow of ideas. Without question, Robert Johnson has plenty of those.

 

let's see... squeeze off the intake ports & retard the timing & hang on

 

NASCAR should assinate this guy before he gives all their secrets away.

[dlaing]

Motoman is also a promoter of high velocity intake porting

http://www.mototuneusa.com/think_fast.htm

Too bad his website looks like regurgitated spam

[TX REDNECK (R.I.P.)]

So anyone running top fuel should get ahold of motoman & this johnson guy to epoxy up the ports. And get rid of those superchargers. And add some slick 50 and some of those 4 prong sparkplugs too.

 

Maybe NASCAR should mandate all races be run with restrictor plates

[dlaing]

So anyone running top fuel should get ahold of motoman & this johnson guy to epoxy up the ports. And get rid of those superchargers. And add some slick 50 and some of those 4 prong sparkplugs too.

 

Maybe NASCAR should mandate all races be run with restrictor plates

You just want them to give you the superchargers to put on your Solex....sly!!!

[Paul Minnaert]

well, now I read this, and looks interesting. So who sends its v11 engine to johnson, to see if he can get a cool running 120 hp out of it?

[GuzziMoto]

Funny thing though, my near stock Buell(the closest I've come to owning a Harley) made almost the same power as his stuff. And the same kind of mileage as well. Interesting stuff reminding us there's more then one way to do it. I think the first line of the last paragraph summed it up well.

I'll take flow and squish over turbulent flow, personally.

[felix42o]

I've always kinda figured our current version of this motor makes pretty good power, considering age and design. It'd be interesting to see if 1) Smaller heads could work and 2) how much of a difference could be realized. The Harley motors make so little horsepower for their size that anything is an improvement.

[Guest rosso mandello]

I am have to know - has anyone out there worked on their (porting) cylinderheads, and is there any gain.

 

I know a guy in DK, who races and makes all the preparations himself, currently no. 1 in the national 600 cc race. He has done a lot of work on 2 cylinders of all kinds, says that there is a lot to gain.

 

ciao Mogens.

[GuzziMoto]

Speed's cycle in MD. ported the heads on my wifes V11 and gained about ten hp. Maybe could of gained more but the guys who did the power commander tuning aren't used to air cooled bikes and from what I saw they tuned for too lean a a/f ratio. Not that I'm saying Speeds is great, I think any decent tuner could get good results, but they did deliver more power. And it's not peaky or anything. It's just stronger throughout the rev range. I would like more squish though.