The long stroke engine is your weak link. If you have a full-pressure 235 cruising rpm is best kept under 3,000 rpm. The faster you turn these engines, the shorter their lifespan. The rods will stretch at high rpm. A brief spin at higher rpm won't do much damage, it's the prolonged stretches that will fatigue your rods. They are made to cruise at the 2,000 to 2,500 rpm range.
