Blower Operation Rationale
Our '88 model had a factory exhaust blower. It was installed with the intake at the bottom of the engine compartment, as though it were a gas engine.
There was a flex hose intake from one of the vents on the transom that sent all the way to the same place in the engine compartment that the (powered) exhaust hose was installed. The two ends were side by side!
After talking this over with the mechanic/instructor at our diesel engine class, I moved the exhaust hose to the top of the compartment, and reasonably near the alternator.
When the old blower died some years ago, a new Atwood "turbo" blower replaced it. The old flexible vent hose is not too expensive and was cracking/splitting... replaced all that as well.
Our mechanic explained that these small sailboat diesels are all somewhat "cooling challenged" by their tight fit and that they are designed to lose about 5% of their waste heat by direct radiation. Thus the need to keep the engine clean and not coated with a layer of "insulating" dirt and gunk, and, also to run the blower while you are using the engine. The later is more important on a hot day with high ambient temps, FWIW.
Since my engine has excellent access to fresh air from the lazerette where one of the cowel vents is located, I got rid of the vent hose run that was, in theory, an Intake.
We have always had a very small pan gasket seap where I cannot get at the flange bolts, and some attendant oily smell when motoring. Running the blower also reduces this to where it is almost unnoticeable.
So, we run the blower to pull out any hot air from the top of the engine area.
Regards,
Loren
'88 Olson 34 with Universal 3-cylinder diesel
