Reconfiguring engine compartment ventilation

Post here if you want to discuss a topic specific to the MV/32, MV/34, and MV/41.
rhumbline2
deckhand
deckhand
Posts: 24
Joined: Thu Feb 18, 2010 11:50 pm

Reconfiguring engine compartment ventilation

Postby rhumbline2 » Wed Nov 09, 2016 11:02 am

On the PDQ 34 powercat, one of the best little cruising powerboats of all time, I think one of the biggest design flaws is the location of the vent for the engine compartments. While running in some sea states, water can come up the transom steps and into the vent, sloshing salt water into the engine compartment. I cruise my boat in Caribbean waters and sometimes get caught out in bigger wave conditions than I would like. I'm seriously considering glassing over the transom step vent and installing two 3" diameter vents for each engine compartment on each side of the aft window hatches behind the queen births. One vent would be attached to a blower. I'll make ductwork to run the ventilation from the vent to the engine compartments. Of course I'll have to cut four 3" holes (two in each cabin) into the shelf aft of the queen births in the aft cabins to run ductwork. This will provide both an ingress and egress for ventilation air for the engines and in my opinion make the boat much safer in open water.

Can someone out there tell me why this is a bad idea?

James Mills
Hull #27 currently in Guatemala
Rhumbline

duetto
admiral
admiral
Posts: 598
Joined: Wed Jun 15, 2005 11:18 am
Location: ICW (32043)

Re: Reconfiguring engine compartment ventilation

Postby duetto » Fri Nov 11, 2016 11:28 am

hi,

before you take the sawzall out why not just raise the output to the top step? would that help or are the waves coming onto the deck?
john & diane cummings
duetto mv34 #23

rhumbline2
deckhand
deckhand
Posts: 24
Joined: Thu Feb 18, 2010 11:50 pm

Re: Reconfiguring engine compartment ventilation

Postby rhumbline2 » Sat Nov 12, 2016 7:57 pm

John, thanks for the reply. Your suggestion is appreciated and might be the best solution. I'm in Florida and the boat is in Guatemala and I'm trying to decide if I want to do this ventilation project or not. Cutting a hole in the top step still puts you into the living area (I think) and makes for the extra aggravation of additional duct work and making it look good for resale - something I'm strongly considering for the second half of 2017. Not being able to look at the boat and then go into my shop and create the right solution is frustrating. I'm working from notes I have about this idea when I was last on the boat in May.

Sticking a piece of foam in the vent and opening up the engine compartment in rough seas is another solution.

Fortunately, I've never seen waves come onto the main deck.

The PDQ 34 is the first multi-system complicated boat that I've owned and it's been a tremendous learning experience about taking care of such a vessel.

James Mills
Hull # 27
Rhumbline

duetto
admiral
admiral
Posts: 598
Joined: Wed Jun 15, 2005 11:18 am
Location: ICW (32043)

Re: Reconfiguring engine compartment ventilation

Postby duetto » Sun Nov 13, 2016 8:15 am

james,

you're absolutely right. to get ducting to the top steps you'd be in the bunks.
john & diane cummings

duetto mv34 #23

Ortolan
1st mate
1st mate
Posts: 29
Joined: Tue Feb 03, 2015 4:54 pm

Re: Reconfiguring engine compartment ventilation

Postby Ortolan » Sun Nov 13, 2016 12:47 pm

James,

The best solution might be to fabricate a dorade box in each engine compartment.

"A dorade box (also called a dorade vent, collector box, Charlie Noble or simply a "ventilator") is a type of vent that permits the passage of air in and out of the cabin or engine room of a boat while keeping rain, spray, and sea wash out."

You could make at home, then mount just inside the vent - the only boat mod would have to be a drain tube from it thru the step below the vent for any sea water to drain.
Russ
Twin Sisters
2006 MV34 - Hull #100
www.esc-pod.com


Return to “PDQ Powercat Forum”

Who is online

Users browsing this forum: No registered users and 2 guests