I have seen a few comments abouts high RPM damage on the 216. Just how tight is to tight. My door plate says 85 hp at 3300. I know hp drops beyound that of course, but what is safe.
I refuse to answer this question! Because Nate will kick my butt! (But in my opinion, if the 216 was not the best inline 6 chevy ever made, why did they use it for for long?) It's a dependable motor (even though it was babbetted and might have 5 lbs of oil pressure). Any well maintained engine is dependable (as long as it is run as designed). It is the longest running inline 6 of anything that chevy ever made. Damn, that was fun, now I will let Nate give you the straight scoop! Maestro, if you please!
216 RPM Vs. Engine Life Yup , it's a darn good engine allright ~ I recall old ones out in the boonies that never , _EVER_ got any attention untill they wouldn't start or stopped running and this was on crappy non detergent oils and watery low Octane gasoline too . Anyway , there's basically two failure points on the venerable 216 C.I.D. Chevy Babbit Pounder engine : You can exceed the oiling capability of the engine and it'll burn out a rod (the good news is : I know of some that still are in use 25 years later , rods banging away) Or , the connecting rod will fatigue and snap off , right below the wrist pin and this is a serious failure as the flailing rod most often then punches a big hole through the side of your cylinder block . So , I'd say keep it around 3,000 RPM's on the freeway and do keep on top of the maintenance ! this means fresh oil changed whilst hot every 3,000 miles or at least three times a year , check and adjust the valves dwell & timing too , this all means the engine runs smoother and less stress . All you needs do is : get a swell/tachometer and cobble up some long leads , run it on the highway once so you'll know at what road speed you're doing 3,000 RPM and then just don't go any faster than that . simple . I knmow there's one lister here who _fully_ blanced and blueprinted his 216 when he rebuilt it and he goes about 3,4000 RPM's IIRC , I'd never , _ever_ do that . Didja know ? 216's tore up the dirt tracks in thier day.....
Yes, Nate I did know that. Heck there's a fellow out here that drags a 51 chevy sedan with a hopped up 216. Once upon a time I had a 50 1/2 ton throw a rod out the side of the block. I changed the oil, tied the rod off to the strut, stuck a rag in the hole and drove her for months. Didn't idle worth a hoot. Wayne