Hi ace.cafe
I am saddened by the fact that you guys are using the same stock cams and not making new ones for this project! Can you not design new cams which can also accommodate the auto-decomp? How about the new set of cams/throttle body etc the Cafe Racer is rumored to come with?
Are we trying to go a little too cost effective with our UCE project?
I have been told by one local RE manager here that C5 in India initially came with a set of cams which would develop play and start making noise quite early and another set which was better than the old ones. This I came to know when I got the noisy cams replaced on my bike.
Also, I remember reading it somewhere on this thread that stock UCE 500 makes 19.8 hp at the wheel, but you have quoted 21 hp in your last post.
Hi,
Well, the main thing to get is more power.
Yes, I know that we have seen 19.8hp at the wheel on the UCE, but there have been several dyno tests of various UCE bikes, and some have shown over 20hp, with one being right about 21hp. It really isn't a big issue, because the power gains will just add to whatever the bike previously had before modding, and it will likely vary some from bike to bike.
So, I didn't mean to make any statement about the UCE by using that one figure as a base power figure. If you add the same numbers to the base of 19.8hp at the rear wheel, the numbers will be 1.2 hp lower for that. I had to pick a number as a rwhp base for the stock bike. If you prefer to use 19.8 as that base, please adjust the final figures accordingly. These are estimates.
Regarding cams.
We have plans to increase the breathing via ratio rockers. This gives us the additional lift which will exploit the head work and can provide just as much power as if we had made cams. We have no plans to radically increase the maximum rpms, and expect to redline around 6000 rpm, or perhaps a little bit higher, and so we really do not perceive a need for longer duration in order to do that. We will get a little bit of duration increase between the .050" points which will effectively increase our breathing duration to some small extent from the rockers.
So, the point I'm making is that the rockers are taking the place of the cams in this case, and will cost less, and do the job, while allowing the auto-decompressor to remain in place.
I think we could design cams which would include the auto-decomp, but having them made is an expensive proposition. Particularly when the valve timing of the standard cams of the UCE already have the timing points and lobe centers approximately where we would want them anyway. What they really lack is lift, and the rocker kit can supply that.
In the event that the Cafe Racer cams and throttle body become available for separate purchase, we can certainly have a look at those and see if they can be used to add to our package.
We will pursue the 535 big-bore too, and will have a piston which will have sufficient reliefs in the crown to allow the higher lift, and also give perhaps just a little more compression too. That's probably worth a couple more hp.
With the ability to program the ECU to move the rev-limiter, we can utilize the slightly higher rev range which we plan, and get to 6000rpm+, which gives us some more revs to make hp, compared to the stock rev limit.
And this again comes down to some selection criteria. We are not currently making this to be a "race kit". That's something else. This is a street rod kit, which is not a full-out racer.
If we have people who want a full-out racer, that is certainly open for discussion, and we can comply with that, at higher cost and more time for development. We are not opposed to doing that.
So, let's talk about it. What do we want in cams that we are not getting with these rockers?
We have a resource to go to for cams, bit they'll be expensive and will take time.
Regarding the decomp, we could move the decomp to a manual decomp in the head if we prefer to eliminate the auto-decomp. Maybe you don't like the auto-decomp? We can change it.
And we could twin plug if people want that.
We can do a lot of stuff. Let's get the ideas out on the table.