Originally Posted by Jono
Yanmar "315" engine is only rated at 40 C at the injector. I just wanted to know what a standard operating temperature was in this region...........
As for the outboards, if we take transmission losses into account ........
I dunno about that method of rating. The evapourating diesel will have a cooling effect but the cylinder air temp has to be high enough for combustion when the diesel is injected. Maybe the injectors stay cool but since burning is taking place against the injector, it's difficult to imagine it does.
Volvo recon a loss of 12.9hp through the sterndrive at maximum revs. Given two u/j's and 2 right angle bevel gear sets I would guess at a typical 200hp lower unit absorbing about 6-7-8hp max. Since the losses turn into heat energy, that's still a fekkin lot of heat to dissipate through the casing! About 5 electric fire bars glowing red hot!
So, no, the powerhead figures are still at variance with the quoted rating.
JK, yep the current hp rating for outboard motors is taken at the prop. The figures in the table are independent measurements. Nevertheless, since the lower units losses of the same make and, I would guess, of different makes are similar, it's easy enough to deduct 6 or 7hp from the figures.
Dirk, could the 300hp rating have been at the drive output and the 315 at the flywheel? Just guessing.