How does the Bird respond to Headwork

thecasualrider · 12-04-2007, 12:08 AM

I've got an engine from a salvaged Bird. Before installing it I want to consider performance enhancing headwork. Does the Bird respond well to headwork? Is there much more left in the head that some good porting will gain.

I'm not interested in different cams or valves, just some good port work and valve job. Also, who's the expert on Blackbird headwork?

Appreciate all opinions/observations: thecasualrider

JB4XX · 12-04-2007, 1:52 AM

Quote:

Originally Posted by thecasualrider

I've got an engine from a salvaged Bird. Before installing it I want to consider performance enhancing headwork. Does the Bird respond well to headwork? Is there much more left in the head that some good porting will gain.

I'm not interested in different cams or valves, just some good port work and valve job. Also, who's the expert on Blackbird headwork?

Appreciate all opinions/observations: thecasualrider

Done right it might get you 10-15hp combined with PC3 or proper jetting, filter and exhaust

Para045 · 12-12-2007, 9:25 AM

PM R1000 as he has done a bit of headwork on his XX recently and seems to like it

MotoRacerGabe · 12-12-2007, 11:41 AM

I got some light headwork done on my '97. put on the full Yoshi RS-3, jet kit, and porting the head all in one visit. The bike is now a monster. I ride my bike daily, haven't had any issues.

thecasualrider · 12-12-2007, 12:16 PM

Thanks for the reply, that sounds encouraging. Who did your head work? and how have you been able to determine power change: seat of the pants, roll-ons with other bikes or dyno?

I know on Harleys and old Jap bikes headwork really makes a difference but on the modern 4 valve heads it's got to be more difficult to extract more HP.

Appreciate any info your can provide.

MotoRacerGabe · 12-12-2007, 12:51 PM

Right next to my mechanic's shop there is a machine shop. while i took it in to get the yoshi and jet kit, there was gonna be a week wait until he could work on my bike, at the same time the owner of the machine shop was talking to the guy that works on my bike. i asked him about proting, just curious of what actually porting is, he took my to his shop and showed me how it all works. he worked on my heads while the rest of my bike sat in my mechanic's shop. then my mech put on the yoshi and jet kit.

i haven't ever dyno-ed my bike. i used to be pretty matched with a friend that rides a stock busa, now i pull on him pretty good especially close to redline. i noticed the front tire wants to come up a little easier than before. sometimes i really get on it when cornering and it was kinda scary when it wanted to come up

I think the whole combination of the full exhaust, jet kit, AND the head work all together made the power increase such noticable.

eliXXir · 12-12-2007, 6:35 PM

The head on the XX is mediocre, compared to today's heads. Getting some headwork done is worth it as long as you do the other things that add up together: pipe, tune, cams.

Combine the 3 and you end up with a pretty impressive outcome.

Now, if you save all that money and instead bought a turbo, you would have the best solution of all and never have to crack the engine open.

thecasualrider · 12-12-2007, 9:18 PM

The turbo solution is interesting but I still like corner strafing the Bbird so any turbo lag and big power rush can be a handfull.

I already have an Ackro pipe and power comander. Regarding aftermarket street cams, I don't see how they can move the powerband up much because the Bird pulls good right up to the cutoff already. So I assume to increase flow they steepen the cam ramps and increase the lift.

Do the stock valve guides handle the aftermaket street cams or does the more radical cam profile shorten valve guide life?

Does anyone still market a street cam for the Bbird?

Anyone that can add to this conversation please chime in. Thanks

Para045 · 12-12-2007, 10:55 PM

Quote:

Originally Posted by Para045

PM R1000 as he has done a bit of headwork on his XX recently and seems to like it

Have you PMed R1000?

R1000 · 12-13-2007, 7:29 AM

Quote:

Originally Posted by Para045

Have you PMed R1000?

I've got a PM and have also replied

thecasualrider · 12-13-2007, 9:15 AM

And thanks for the detailed reply R1000. R1000 what is the manufacturer of the cams you're running?

I wouldn't mind paying good money for a first class port job, when you consider the performance gain that will last the life of the engine without effecting reliability or maintenance it's a performance bargain.

R1000 · 12-13-2007, 1:36 PM

I'm using HO18 cams from Kent Performance Cams Ltd

They work great in combination with the other mods as shown in the dyno graph below. The current power curve is the dark blue one on top, starting with 40 rwhp at 3000 rpm and ending at 153 rwhp. The midrange power is awsome, like almost 40 more horses than a Yamaha R1 200t at 7 k.

The next picture is the actual dyno printout where the modded bird is the upper thin grey line that is a bit hard to see.