Re: How low will a diesel run (and not be harmed)?
Oyvind I have a new Beta 14 (13.5 hp) this is the same engine as the lower RPM model which is rated at 10 hp. Same block and all except the 10 is governed at 3000 rpm 10hp and mine is governed at 3600 for the 13.5 hp. It is a really nice smooth running diesel. I rarely run it above 2200. Usually right there at 2000 is all I need to push my boat.
I have a temp gauge on mine and the engine still gets to the correct operating temperature even if I run it at 1500. It just takes a little longer. The thermostat is what controls this, not the RPM you run the unit at. The RPM just determines how quickly you get there, temperature speaking and speed wise obviously. The only problem with running a diesel with little load, and short time intervals is that it doesn't have time to get to operating temp and the condensation in the cylinders doesn't have time to vaporize and leave the oil enviroment. Simple to solve just warm her up a little more if you are going to short run.
Diesels are built to be lower reving than an equivalent hp gas engine, they are intended to generate the torque and hp for the application at hand at lower rpms. As far as fuel economy goes my Beta used 3 gals of fuel for the entire season last year. We usually sail on/ off our mooring but we always start the engine and warm it up just to be sure she'll go if we need it.
Every diesel, as I am sure you have already noticed, has a sweet spot where she'll run the best. My happens to be right at about 2450 when warmed up. I just go at 2000-2200 because our boat is a canoe stern and much more hp and the stern wants to start to bury.
Last edited by emichaels; 03-17-2009 at 03:31 PM.
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