Quote:
Originally Posted by Sony2000
Nobody maintains 3500 rpm under load. The engine was designed to do it for a short period of time. It was designed to do 2600 rpm cruising on a smooth sea with low winds. If there is a good chop and strong winds are not in your favor, then 3000 rpm is available to maintain control. Low rpm at WOT, is running the engine at maximum load on pistons, connecting rods, crankshaft, all the time. A 20-30hp diesel would be more appropriate.
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Nobody is going to have 3,500 rpms at hand to turn up too, even if for a brief moment unless they about are running around a 10x3 prop....
Math shows us say the Indigo prop:10x7.4 inches
Max rpm for most guys with this prop is 2,400 RPM so thats
it nothing left at WOT
Now we want to free the engine from this destructive force of this too aggressive prop, so One inch of pitch gives or takes about 200 rpms,
so we need to free this engine to be able to reach 3,500, thats 1,000rpms away.
So basic formula rules we need 5 inches less pitch. 10x2.4Prop
Good luck with that.
As for the argument of load from not reaching that 3,500 rpm, well a little reading around here has shown this motor is basically a anvil, and I have yet to read a post that says I killed this motor from not letting it turn to the factory number.
Diesel engines will die a quick death if overwheeled, as well as car engines in boats that cannot free them selves.
But this engine with no compression and a flat torque curve seems to laugh at the wisdom brought on by experience from other combustion engines.