Port n Polish


Hi all, this is my first post so I'll try and get on subject. Finally flowed a Busa head on my bench and couldn't believe it 133cfm@ .350" int. and 76cfm@ .350"  63% ratio int. to ex.  With a little polishing ( removing casting marks) etc. flow up 8cfm. with a .380" cam on intake and 6cfm with a .350" cam on exhaust. Keeps flowing more at higher lift but int. to ex. % not what I expected. Looks like a larger exhaust valve would help as I've been used to getting ratio to around 80%. Has any one here had any head work done and are willing to share specs.


 Guys, I guess no one is talking. From my first tests it looks like lots more potential. Just playing with a hurt head I came across that the cam chain tensioner failed in a couple of years ago. This engine(Busa) will pick up big time with a very little work, that statement will probably bite me in the ^ss. But seriously as if it doesn't already rule, minor port work and the right combo of cams will leave other Busas behind. I'm currently porting some demo heads for display and will post on this subject when I get time to play with port # 2. Two months in front of the bench is and two more to go before our season starts again.  


Hi James, 1 cfm. has the potenial for .43 H.P., I'm not sure what stock cam lift is but with minor porting and .380" intake, the H.P. figure should be up at least 14 H.P. at the crank, roughly 15% less at the rear wheel. This head flows almost as much as my drag bike and I was making 217@ the rear wheel a little differant combo than the Busa but the potential is there.


Hey dlind,
who can do this kind of work, and how much do you think is a fair price??? Keep experimenting, I'm interested to see what combo works best....


I have a 1498cc Busa with stage one web cams making 207 hp. Don't know what flow spec's on head though. knebnr


Hi guys, hoping to get time for second port, but I think cams are the best bet cause it keeps flowing more at higher lifts, as for price I don't really know what to tell you. Personally I think most shops have some old guy like me doing their work for a small price. I won't get into that one, just find that old guy working out of his basement with a flowbench. Mean while check out Moto Man. I'll report back latter.

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