3 ms·
TLDR: HP = torque x RPM / 5252 Such big engines runs at low RPM, below 1000 (I have not looked at this particular model). It's common for boats to run at 500.
by jeromenerf 6y ago
TLDR: HP = torque x RPM / 5252
Such big engines runs at low RPM, below 1000 (I have not looked at this particular model). It's common for boats to run at 500.
In comparison, my 2.2 liters 2007 diesel mercedes runs at around 2400 RPM at cruising speed of 65mph, which is its max torque. Max HP (150) is achieved at 3500 RPM. It's by no mean a sporty car but it's low RPM torque allows to pull the horse van easily.
The freight carrier boats can feature impressive diesel engines, of thousands of liters, producing millions of Nm of torque, hundred of thousands of HP, at ~100RPM.
- marshmallow_12 6y agoso the goal here is to minimise revolutions per minute. Is this to increase stability or efficiency? Or is it just so the engine won't shake itself to pieces?
- lmm 6y agoThe engine is probably designed for fixed RPM, because that way it can be tuned specifically to that RPM. High RPM (past a certain reasonable level) makes all the mechanical engineering harder, so you'd choose a level that's high enough for the power you need, but no higher. There's a tradeoff because to increase power you can either increase the RPM or increase the physical size of the engine, so you do whichever is easier based on the constraints of how it's being used.
- jeromenerf 6y agoIt’s always a trade off of many dimensions. Usually, if you are looking at resistance (pulling weight, navigating water, ...) more than speed, a bigger and slower engine provides the torque you want at low engineering costs, more resilience, less cooling constraints ... For some cultural reasons, American muscle cars featured big relatively slow but torquey engines compared to their Italian counterparts.