Originally Posted by zinco
I am buying a 28' houseboat with this picture of the engines, any info would be much appreciated...in regards to this photo..any guess would be much appreciated. ie...what kind, horsepower, gpm etc etc is the thing on the left a generator. thank you snickers are o.k. too
A normally aspirated automotive/marine gasoline engine typically produces around 10HP/Gal/hr. at WOT. That is a generalization of course, but it is a good starting point . Most I/O installations have actual fuel consumption a few percent below that number. In your case, at WOT, I would expect each AQ170/B30 to consume up to 17Gal/hr., but probably more like 15-16Gal/hr. as installed in a boat with the correct propellers and pitch. Since you would operate the engines well below their full rated power, it will be very dependent on the speed at which you choose to operate your boat. With twins operating at 50% power you would conceivably see around 16Gal/hr. At 33% power, 10-11Gal/hr. and so on. Without Volvo's published power curves, knowing the corresponding engine RPM's for those power settings will be anybody's guess.
Most, if not all AQ170s came from Volvo with Bosch marine alternators. As I recall, some were pretty small, around 35A or so. Aftermarket replacements are readily available though.
Hope this helps.