Brendan probably is the closest, to what I would conceder the RPM that this (216) engine could safely run at. The torque and horsepower curves cross at around 2750; this is where you will feel the power begin to drop off. The gross horsepower peaks at 90 at 3300, however it won’t be pulling as hard at that RPM as it would be if it were in the torque curve. If I was hauling a load I think I would operate it in the 1200 and 2000 rpm range. I cannot see any problem with pistons or valves operating an engine at 4000 rpm.
Of course once your out on the autobahn and up to cruising speed you don’t need all that much torque and running the engine up to 4000 rpm should not hurt it. Now all that being said, one has to conceder that this would only be applicable to a new engine (rebuilt is not new) with everything broken in and in proper adjustment.
One other significant thing I did notice in looking through the Chevrolet Truck Data Book is that none of the charts go above 50 mph. This would strongly indicate that none of these trucks were designed to operate over that speed from the factory. Also as we all are aware if is, the higher the rpm, the shorter the life of the engine, so we have a balancing act going on here.
Denny Graham
Sandwich, IL
