your right in one sense in what ur saying furyflyer, but 1850 is a better idea, since as you say with the os32 it's ideal hp range is around 1750, when ur running 1850 and you load the head engine up it drops straight down into it's optimum hp range increasing power to the blades thus keeping the head going, much as stated by curtis youngblood when he comes to set his headspeed and gearing up, i was gonna say that by many 3d flyers standards 1850 is a very conservative head speed, i just prefer it around that area for me and i believe it's perfectly safe, in fact there's a guy at my club like raptor dude who runs a head speed around 2000 all the time on a raptor 50 and i've never once seen him have a failure despite the fact he really punishes that helicopter, along with thousands upon thousands of others, it's worth noting though he does get through engine's at quite a rate though hehehe, but another guy at my club used an irvine 39 on his raptor 30 for a long time and that engine could pull the heli through just about any manoeuvre, and his raptor always sounded like it was running at least into the 1900's.