Ace, was the development of the original Fireball more or less straightforward than the UCE?
And very glad to hear that progress is being made.
Scott
Hi Scott,
The Fireball was very slow getting underway also. It actually took a year for me to get my first prototype head out of Mondello. There were some hurdles to overcome, mostly in the re-engineered valve train, which took some time and effort to resolve.
I would say that the Fireball was overall a more difficult job, because we hadn't paved any of the way with a previous effort. Because of my experience with the Fireball, I have a better handle on where this UCE project has to go, and some of the techniques we pioneered on the Fireball can be used on the UCE. I plan to use the same valve gear that the Fireball has on it, with the beehive springs and such, on the UCE too. It's too good to not use it.
There are a lot of similarities between these two engines, but also some divergences.
For instance, the intake port size is about the same on both. The UCE has a slightly smaller set of valves, and the semi-bathtub chamber, which impede flow a bit in comparison to the larger valved hemi-head of the Fireball.
Interestingly, both the UCE and the Iron Barrel show the same flow problem in the intake port, and so we can use the same techniques to solve it. But the exhaust port in the Iron Barrel was too big, so we crutched it with some flow techniques and a shorter lift on the exhaust cam, and got our flow ratio fixed up that way. The UCE has a smaller exhaust port, and that allows us to have some room for shaping, and we should get a better result of the exhaust port in the UCE.
The biggest difference is that on the Fireball we had complete freedom in the intake for whatever carburetor we wanted, and could jet any way that worked best, very easily. And we had a fully adjustable ignition system which, while a bit crude, allowed us to adjust it any way we wanted it, very easily. So, that took a lot of pressure off, because we didn't have "black boxes" to try to deal with, that do things on their own that we might not want.
The Iron Barrel flat tappets had essentially no limitations for us. They are very applicable to a performance package just as they are. On the other hand, the UCE hydraulic tappets have issues with higher revving, which can be overcome, but it's another fly in the ointment to deal with. The rollers are nice, but they are very heavy, and the roller tappets require different kinds of cam profiles, so we can't just use our Iron Barrel cams in the UCE. Most of this stuff that is designed to be a convenience on a road bike, are an impediment to a performance machine.
In terms of flow, the Fireball flows about 195 cfm at .350" lift in the intake. Right now we are only at 165 cfm at .400" lift on the UCE head. Clearly we have some further improvements to make, and we know what to do. The two-edged sword is that the more we make this baby flow, the further we get from the stock EFI map, and the more important the new ECU or re-map becomes.
So, we have a set of "goods and bads". Not anything that can't be overcome, but some things that are sort of a pain in the ass. But, we'll get there in the end.