| Author | Message | ||
     Kenb |
I've always wondered why nobody does this ? Even the XB still has the intake in the middle of the V. Is there little benefit to be gained from having two seperate intake tracts ? I thought a straight intake tract was better for flow ? using two front heads would get both exhaust ports facing forward and both intake facing rearward, although exhaust and intake would be on same side. Just curious as to why nobody attempts this. | ||
| Mikej |
There are quite a few dual-carb'd tubers around and at least one company (Kuryakin?) makes a dual-carb inlet. Also, there have been some XR-style intake-exhaust setups on various Buells in the past, probably a few pics floating around the site here. Basically though it seems that the effort does not always add up to the desired results per amount of effort extended. I've still got a spare carb designated for a dual-carb experiment, but that project is currently on the back burner for the time being. This one is for the big twins:  | ||
| Benm2 |
Tilley's old pro-thunder S1 had dual-carbs. Others have done it to. The XR750 configuration puts the rear-head carb under your right leg, not very good street configuration.  Ducati's also have the intake tracts in the middle of the vee, as to aprilia, honda, & suzuki. If I had to guess, current XB-heads are still setup for side-feed so they could be cross-used on the new Sportster. It seems there would be a benefit to a more vertical intake tract, perhaps with two throttle bodies, but it looks like "other specifications" dictated a more accomodating configuration. I would also guess that the Buell's new FX bike has a slightly different intake manifold... | ||
| Kenb |
Hmmm, yeah the ergos immediatley come to mind as a reason not to. The aprilia, honda, & suzuki have wider Vs (60, 90 degrees ?) to fit straight shot intake runners. I just look at that intake manifold and think there must be some ponies in getting the bend out. Maybe not, could be it aids in turbulence. I'm no flowmeister but from basic fluid dynamics I remember that bends decrease velocity at a given pressure. | ||
| Djkaplan |
The original Buells used the XR1000 engine, so I'm not sure packaging problems or ergonomics would keep an XR-type head arrangment from being feasible. | ||
| Spiderman |
Have you seen a RR1000's body work? If you look closely you can see where the rear air filter is knotched for the body work. The knee actually bends in between the two filters just like on the old XR1000 sporty's. It is very fiesable an would be a cool project. The only problem I have is I Have two front heads layin around the garage. Any one wanna make up some manifolds an Exhaust??? | ||
| Sportsman |
Not sure, but wouldn't the back exhaust run into the carb on the front head. A little too tight, I think it would take opposite side, "trick" XR style heads to pull it off. | ||
| Loki |
I wouldn't mind seeing some good detail shots of the old twin carb set-up on Tilley's old race bikes..... | ||
| Djkaplan |
No pics, but here's how it's done. http://www.sportster.org/tech/misc-ironhead/two-front-heads.html Does anyone think they could scare up some pics from this article? |
