CCWorks

Making dreams, reality. One bike at a time

†††††††††††††††† The saga has begun. I am currently gathering information on a single carb intake. The ultimate Virago will have a single carb however it will not exit on the side. It will go up and over the front cylinder and exit pointing to the front of the bike. Right now I am trying to find a way to bend the tubing in a way that is fast reliable and will give the tight bends needed to make this a feasible accomplishment. Other systems use a cast aluminum manifold with silicone sealant on the ends. Not to sure about that as silicone will dissolve in contact with gas. I have not seen on of these units personally but I have reservations about how they are done after seeing some of the other products offered by the manufacturer. I hope to build mine out of steel tubing for durability and strength.

†††††††††††††††† Right now the main issue is how to make the tight bends in the tubing to get everything where it needs to be. I can see why some cast the part. With cast it is easy, make the mold, pour the mold, bingo, manifold. One thing about molds, though, is core shift. If care is not taken and tolerances not kept a close eye on then you never get two manifolds alike. Ports could be off from the intake plane which causes fuel shaving and fuel to puddle. All causing tuning problems. I have chosen to attempt using tubing to insure tight tolerances and to insure that all manifolds are the same.†

†††††††††††††††† Iím trying to incorporate what I have learned about manifolds from being an auto mechanic for the past 20 years. In that time I have worked on many different kinds of engines and have done extensive research in manifold design in the automotive industry. This research is what† lead me to the idea of doing this manifold, and the fact that I own the bike.

†††††††††††††††† This particular manifold will have low end torque as the main basis. In my years I have learned much about how to boost low end torque. The main key (besides the cam) is a long runner dual plane manifold. Many tests have shown that the longer the runner the better the torque curve is going to be. The dual plane boosts low end power because it gives a better signal to the carb allowing better throttle response. So how does this have anything to do with a Virago? Stay with me, Iím getting there. The dual plane is out the window as you only have two cylinders and dual plane would mean dual carb for this and that is what we are trying to get away from. On top of that you have very little space to get fuel from point A to point B. You are fighting an up hill battle right off the bat. Most manifolds Iíve seen have a VERY short front cylinder runner with a long going to the back. This will cause the front to run a little richer than the rear and will give a different pulse to the two cylinders. I am going to try and put runner length the same or at least close to same to ensure proper pulse and flow to each cylinder. I am not sure as to how feasible this will be but we will see.

 

Stay tuned more to come

Single Carb Intake

This is a document in progress please check back for updates.