Okay, we have produced a lot of Bullets which can do The Ton, and we have extrapolated the data from our past work on the earlier engines to make a real attempt at doing it with this UCE/GT platform.
My opinion is that the aim should be to increase torque as much as is practical, and move the torque peak a little higher in rpm, and use better breathing to hold on to it as long as possible, so higher hp can be produced at higher end of the targeted rpm range.
There are various techniques to approach with, and our past behavior has been to increase breathing significantly, increase compression within the fuel limits with the combustion chamber involved. and to work with the wave tuning in the inlet and exhaust to help optimize the power in the rpm range needed to get over The Ton.
Our valve timing approach has been different than Hitchcock and most of the other UK tuners, who use relatively narrow lobe centers and large overlap periods. Our approach on valve timing is to use a later lobe center and relatively shorter overlap to extend the rpm range while retaining the lower rpm torque quite well, in conjunction with the high compression piston that works correctly with the later intake valve closing timing, so that we get the desired results. Our peak hp numbers are usually a little lower with this method, but our curve is usually broader and more conducive to enjoyment on the road, being less "peaky".
Hitchcock's typical cam profiles are quite peaky, and not everyone's cup of tea. I prefer less peaky curve with broader torque. Just a difference in preference. I'm not saying either way is "right" or "wrong", but just stating my preferences.
I can state that we have head several UCE heads on the flow bench, have analyzed the flow activity with stock valves and ports, and also with various modifications to valves and ports. As you know, we have also created an entirely new cylinder head to overcome some issues which we felt were too expensive and time consuming to do to a stock cylinder head for commercial purposes.
The point I want to make here is that we can speak with experience about what these heads can do, and where their shortcomings are, and our opinions on how to improve them, based on hard data.
Regarding your stated static compression ratio, I think that might be a little bit high, based on a stock combustion chamber and the available fuel in the US. Maybe the German fuel will withstand the higher compression than our US fuel. We aim to have a 9.5:1 static compression ratio. If you intend to cluse the intake valve much later in the cycle, then the 10.5:1 might work, if the closing is late enough.
Topic: I want to do the ton......but how ?! (Read 53320 times)