PDQ OWNERS FORUM

We had a high capacity Electromaax 180 amp alternator installed on our Port engine self-destruct recently. The source of the failure, as best we and several "experts" we consulted can determine, is 2 faulty solder connections at the rectifier on the alternator. There are no other signs of over-heating inside the alternator. We are going to replace the defective alternator with a different brand high capacity alternator (Balmar 165 amp "AT" model). (We need a high capacity alternator to charge our 4 - 220 amp house AGM batteries.)

As part of the "fix", we are looking at the question of how HEAT generated by a high capacity alternator is handled inside the port engine compartment. Currently, there is NOT much air flow at the front of the engine where the alternator is mounted. So, we are considering doing something to improve air flow inside the engine compartment. Not sure what that might be at this point.

I'd like to know if any of you have dealt with this issue and what you did to improve air flow inside the engine compartment.

I guess you could run the blowers on that side and try to monitor if it made a significant difference. If you felt really warm air coming out the exhaust after a good run, it would seem to be helping.

Duane, thanks. That was my first thought, but I don't think it's a very effective solution. As everyone here knows, the engine is rather sealed off from the overall compartment area. The only way for air to get INTO or OUT OF the engine area is through the two vent holes in the sound baffle that sits on top of the engine area. Turning the exhaust fans in the back of the boat seems like a very ineffective way to move air into and out of the front of the engine. I'm wondering if anyone has addressed this issue in a more aggressive / creative way.

Mac, following your sound logic, you would need to have a vent at the front of the engine space (ideally close to the alternator) and then draw the air through. That would likely do the job, but obviate the sound-deadening.

On many high-end alternators with external regulation, you can set the maximum output to significantly below the maximum (say 70 percent), which makes for a lot cooler running and more efficiency. You might want to investigate that, too.

Good luck.

There is actually another major source of air into the engine space. If you look under the engine where the engine mounts are located you will find a large opening into the bilge "bypass" area. This area allows moisture and air to flow from under the refrigerator or head area aft to where the bilge pumps can pump it overboard. If you were to place a fan over one or more of these holes it would add cool air to the engine space. actually, now that I think about it that "bypass" area is completely open in front of the engine pan area so one could place a fan there as well and it might work even better.

Very interesting suggestion, Dick. So both areas connect all the way to the fridge area? I’ve noticed the areas in front of and on the side of each engine and wondered if they had a purpose. Do you know if there is a way for fresh air to be drawn in from behind the fridge?