Hello again
Several years ago now on the UCE thread I posted a tongue in cheek message about "Announcing 40 hp UCE" . Basically at that time I wanted to explore ACE's thoughts about the potential for doing to the UCE what he has done with the iron barrel Fireball. And, in my recollection , he was not initially overly enthused but waxed to the idea as the responses came in .
Looks like that day is here (well, almost) .......and, if I understand from the tid bits in this thread , even more than I had dreamed of .
A couple of questions:
1) It may be already discussed in the thread or elsewhere, but if so I didn't see it: Will the new 535 head work with the exisition OEM EFI , or does it need a replacement or add on like Power Commander ?
2) Can the new 535 head be bolted onto a 500 UCE? Or is it diplacement specific : If so, can an aftermarket 535 be applied to 500 UCEs to take advantage of this?
3) I am guessing the vibrations will be the same as the 535 (since the big reciprocating mass elements won't really change) , though riding it may be different as it may prefer to "live" in a different rev range in daily use becuase of enhanced torque ......Would that be approximately correct?
4) Can you tip your hand on a power estimate for this new 535 format ?
5) "Tractable , roadworthy , useable power band " if I recall were some initial objectives for the project: How do you think this would translate to real world riding? Easier upgrades? Better passing power? More comfortable highway cruising speed with a little left?
All very exciting. Thank you , Nigel Ogston
Hi Nigel,
Thanks for your patience!
Regarding the questions, I'll try to give the most accurate info that I can, with the caveat that things are not finalized yet, and I can revise my statements as the CAD becomes final.
1) The existing EFI parts will all bolt right on as they are now, but the programming will most likely need to be altered with a Power Commander or similar product. I say "most likely" because it will flow more air than a stock head, and this would likely need more fuel. However, in our previous products, we have seen that our heads require little or no more fuel than the stock versions of the carbureted models. This is because the efficiency of our heads in atomization of the fuel, and the improved combustion efficiency, was able to make use of the previously wasted fuel that the stock bike under-utilized. Whether this will still be the case with the fuel injection, must be evaluated. My gut feeling is that some changes with a Power Commander will probably be necessary. We will find out when the heads are on bikes, and see how they work.
Additionally, the stock ECU has a rev limiter which would be nice to get out of the way, so we can access the higher rpm limits that we have in mind. We expect rpm limits around 6000-6500, and that will need a Power Commander or the like.
2) The 535 GT head can physically bolt on to the 500. However, we are using all the room we have for the bigger valve sizes that are permitted by the larger bore. This means that on the smaller bore, the valves will be shrouded by the closer proximity of the smaller bore, and thus will flow less air in that environment than with the larger bore. Actually, only the inlet valve will be shrouded to any significant extent. There is a "fix" for this, if a person wanted the big valves on the small bore. The top of the cylinder barrel may be fly-cut or cut with a significant chamfer at the location where the inlet valve is closest to the cylinder liner, right at that edge of the barrel. This is sometimes called "notching" or "relieving" the barrel. We can perform that machining operation on barrels if requested. The effect of this mod provides a little extra room around that edge of the valve for flow to get out, by removing the restriction in that portion of the barrel. It will add a couple of cc's to the chamber volume, and slightly lower the compression ratio, but probably not noticeable.
The other possibility would be to use a slightly smaller set of valves in the head with the 500 bore. I have discussed this option with Mondello's, and it may be possible too.
One of the reasons for this is that the valve angle is steeper by about 8 degrees, and so the valves move more directly downward than before.
3) The vibrations will most likely remain unchanged, unless bottom end work is performed. It is possible that the added hp will cause the bike to labor less at the higher speeds, and that might help some. All the Fireballs do seem to be much more relaxed at speed than the standard Bullets. But if the bike currently vibrates badly at some rpm range, I would probably expect it to still do that because we are not doing anything to modify the bottom end parts that would be causing it. But, modifying the bottom end is an option for owners who wish to do so.
4)Regarding power, the available rev range will be higher, but the torque curve is going to still be real fat and wide. The power increase will be everywhere in the rpm range. You will still be able to ride at whatever rpm you want, and have more power. This will include better acceleration, passing, top speed, cruising, everything. It should be able to do everything the other Fireballs can do. The one question mark is that the stock cams are pretty short duration, and so I don't know exactly how high the rpm limit will be until we try it out. The much higher valve lift can go a long way to helping increase the rpm range, but at some point the duration will fall short. I don't know exactly what rpm that is going to occur yet, but I think it will be around that 6000-6500 rpm range we target. We'll have to see how far those stock cams can take us with our added valve lift and breathing improvements. I do have another option for custom cams that has opened up recently, which may offer more rpm range for those desiring it. I really think that for most users, the stock cams with our head will give all the power and rpms they realistically will use, unless racing.
We also can offer smaller rocker ratios as options, if other cams from other makers might be desired, but I cannot guarantee compatibility with other makers cams. I could offer opinions based on the specs of the cams that might be considered.
I think 40 hp is plausible, but that will not be the rear wheel figure. Rear wheel peak hp realistically will probably be in the 33-34 hp range, as a guesstimate. But peak hp at 6000 rpm is much less important in the real world than the power curve in the normal riding range. Peak hp is a big buzz word, and it is mostly driven by high rpms. This engine is going to be rpm limited to 6000-6500 rpm, and that is going to hold down the peak hp number. But peak hp at high rpm really isn't the story with these engines, although it gets the attention in print. The torque is going to get a huge bump from these high ratio roller rockers, larger valves, and higher compression with a fast burn squish chamber. That's where people are really going to feel it in the real world. This is what will impress with pulling up a hill, riding with a passenger on the pillion, passing cars on the highway, accelerating from any rpm, cruising at higher speeds with authority, and generally feeling very powerful. Because the power will be increased all thru the range, and not just at the top. Most people do not ride at the very peak top of the power range, unless at the track. We have learned from all our past experience with road bikes that the wide power range is what people really want.
A few tidbits of info on the current status of the CAD rendering is showing the valve angle made more vertical, changing from a measured 27.5 degrees(stock) to 20 degrees(ACE). The roller rockers will be individual shaft type, with 1.7:1 ratio, giving about .500" max lift at the valve(inlet), and about .470"(exhaust). Valve sizes at this point in time appear to be 1.8" inlet, and 1.6" exhaust. Flow is probably going to peak around 200 cfm, but that remains to be tested. All inlet and exhaust and other bolt-on things are located exactly the same place as before, so all stock equipment will go right on where they normally are now. Compression will be increased to between 9.5:1 - 10:1 with a smaller chamber that has a new efficient shape with squish and dual plug capability.
Hope that helps.
Tom
Topic: Ace GT Head Project (Read 247650 times)