Re: Redline/Maximum Continuous Operating RPM - Packard 6 Cylinder Engines

Posted by Owen_Dyneto On 2016/2/23 11:42:37

Rather obviously in addition to engine condition and gearing a lot depends of engine design. For example with 5" stroke engines and poured babbitt bearings you want to be more conservative with sustained RPMS than you would with a shorter stoke and thin-wall insert rod bearings. My '34 has 17" tires and a 4.69 rear axle; I like to keep it just under 2000 rpm for a sustained speed which corresponds to about 45-48 mph though I don't mind going to 50 or 55 for short periods if conditions mandate it. The engine with poured babbitt bearings did go about 80,000+ miles before I got my first lightest hint of rod knock so obviously those conditions were not abusive to the engine.