The only downside of having the preload constant is that at some point in increasing the travel, you may drive the hammer spring into coil bind.... That can't happen when you are adjusting the travel on an MRod style hammer.... Adding travel decreases preload and the maximum compression remains the same....Bob
I don't understand how reducing the hammer travel will increase the efficiency at a given FPE level.... You will have to add preload to the spring to get the energy back.... For a given energy, if you don't change the mass, you have to keep the velocity the same.... To get that velocity, if you decrease the travel you must increase the spring force and vice versa.... Bob
Having the adjuster NOT affect the preload will make the travel adjustment much more linear, effective, and easier to understand, all good things.... All I was saying is that I don't see how using less travel FOR THE SAME FPE would increase the efficiency (because you have to increase preload to get the velocity and energy back).... Since you are looking to reduce the velocity and energy and you are already at minimum preload, then this new style adjuster should work well for you.... Bob
On the efficiency 'thing', it is the momentum the valve puts back into the hammer on close that the travel adjustment can't change; only the hammer mass will have an effect on that. Making the lift high, but dwell short is where hammer mass comes in. For 12 FPE energy levels, I suspect a lighter hammer will get what you want. Considering the ease of hammer swapping, it looks like a fine exercise to try. say maybe 20-23 grams? It looks like a max efficiency for your set up will occur at a maximum spring/minimum hammer mass scenario.going to try a few shims on the two o-ring/light hammer 2263. Shoot for an 880-900-880 tune across __ shots( should be 30 plus as I am at 30 now with 50% more spread ).cheers,Douglas