Blower help on 1964 38' CCC
We got the engines firing for the first time in 15 years! The boat was repowered just before it was put on the hard, and now we're working through the remaining systems.
Next up is the engine-room ventilation. I’m assuming I should have one exhaust blower on the port side and one on the starboard side, with the pickup hoses low in the engine room and exhausting through the rear transom vents. Correct?
For the fresh-air side, the original chrome side vents feed into fiberglass chases built into the hull wall. Do I need blowers pulling fresh air through those side vents and into the engine room, or should they remain passive?
There is a 4" circle opening in each fiberglass chase into the engine room (highlighted in the photo). Is that sufficient for the fresh-air intake, assuming I’m running two 4" exhaust blowers?
Thanks,
Steve
On our 42, the vents are all passive... two on the aft, two on each side using gutter material as Jon Welge mentioned. The blower is connected to a flexible vent tube that works it's way to the centerline of the boat, about 8" - 10" above the bottom of the keel. As normal, we run 5 minutes prior to starting the boat. While underway, the passive vents do their job to move air into/out of the engine room. I like the idea of having alarms added for water and fuel fumes... but I don't know that I'd try to over-engineer for venting... but that's just my .02. Most of our Commanders have easily survived 50+ years with this configuration.