Wow!! Ace, those are incredible results. Are you going to use the same compression ratio as the standard Fireball? cochi
Hi Cochi,
Thanks!
We will vary the compression ratio to suit the application.
This head will be our racing head. So, the racing bikes will have as much compression as we can give them with the fuel that is used. Some racers might use methanol, and could use somewhere around 13:1.
Bikes that will run on the street can use our normal 9:1 with pump gas, or they could run some higher compression if they want to use octane booster or if they have access to av-gas or some other high octane fuel in their areas.
This head's flow result is about all that we can get out of this factory casting. We are already welding up certain areas where we exceeded the available aluminum around the port. And our rocker system is designed to give enough lift to really use all of this port. It's not that we made it all that much bigger, and it even keeps the same 32mm entry. We just re-shaped it and raised it up for a better approach angle to the valve. Giving the air a straighter path into the cylinder with less turning is a big thing in a performance application. And to do that, we had to bust through the port roof into the valve spring seat area, and re-weld that all up and machine a new spring seat, and then shape the new port roof up higher than it was before, and create a new valve guide support boss, and shape the whole thing to flow more than ever before. This is not a cheap and easy process. It's all done by hand on the bench by real experts cutting and welding new port passageways, and using hand-operated die-grinders to work out this new shape and grind these ports one at a time by hand, and testing them on the flow bench for results as they go along.This is only done when you are going for the maximum.
So, in essence, yes this is our racing head, and it can be used in a street application where the compression is limited for pump fuel.
It would be considered a viable option for those who feel they want to move beyond what a regular Fireball can do, and have some expertise in using and maintaining a sharp-edged performance machine.
We still expect our Fireball 535 to be our most popular product, because it is very satisfying to use on the street, and it costs less, and is more approachable by nearly any normal Bullet user. This Raised Port system, on the other hand, would be a natural progression for a Fireball owner who wants to step up to the next level of high performance, but might not have the money or desire to buy a Manx or a G50. It's a specialty custom-built product with an exclusive nature and a limited market above the level of the Fireball. We do not expect that the everyday commuter Bullet owner is going to be riding around on these. Even the Fireball is a pretty exclusive product that only a couple dozen people even own now. There will be even fewer lucky ones who will own this.
If anyone were to ask me, I would say that more people should own a Fireball. The Fireball is really a spectacularly enjoyable street ride, and is what a Bullet really should have been from the start. Reliability issues solved, very streetable in traffic, guaranteed to put a smile on your face when you twist the throttle, and can do "The Ton".