Managing heat in engine compartment

Post here if you want to discuss a topic specific to the MV/32, MV/34, and MV/41.
User avatar
AMCarter3
admiral
admiral
Posts: 212
Joined: Thu Apr 21, 2016 8:32 am
Location: Bellingham, WA
Contact:

Managing heat in engine compartment

Postby AMCarter3 » Sat Apr 07, 2018 3:10 pm

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.
Attachments
IMG_4335.jpg
Mac Carter
2006 34' PDQ PowerCat "All Heart"; MV 98
Bellingham WA

deising
admiral
admiral
Posts: 172
Joined: Mon Sep 15, 2014 3:48 pm
Location: Punta Gorda, FL
Contact:

Re: Managing heat in engine compartment

Postby deising » Sat Apr 07, 2018 4:15 pm

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 Ising
m/v Diva Di
Punta Gorda, FL
2006 PDQ MV 34 - hull 91, 75HP, 3-blade

User avatar
AMCarter3
admiral
admiral
Posts: 212
Joined: Thu Apr 21, 2016 8:32 am
Location: Bellingham, WA
Contact:

Re: Managing heat in engine compartment

Postby AMCarter3 » Sat Apr 07, 2018 4:29 pm

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 Carter
2006 34' PDQ PowerCat "All Heart"; MV 98
Bellingham WA

deising
admiral
admiral
Posts: 172
Joined: Mon Sep 15, 2014 3:48 pm
Location: Punta Gorda, FL
Contact:

Re: Managing heat in engine compartment

Postby deising » Sat Apr 07, 2018 7:24 pm

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.
Duane Ising
m/v Diva Di
Punta Gorda, FL
2006 PDQ MV 34 - hull 91, 75HP, 3-blade

DickTuschick
skipper
skipper
Posts: 68
Joined: Sat Aug 30, 2008 3:38 pm

Re: Managing heat in engine compartment

Postby DickTuschick » Mon Apr 30, 2018 3:41 pm

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.

User avatar
AMCarter3
admiral
admiral
Posts: 212
Joined: Thu Apr 21, 2016 8:32 am
Location: Bellingham, WA
Contact:

Re: Managing heat in engine compartment

Postby AMCarter3 » Mon Apr 30, 2018 4:57 pm

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?
Mac Carter
2006 34' PDQ PowerCat "All Heart"; MV 98
Bellingham WA


Return to “PDQ Powercat Forum”

Who is online

Users browsing this forum: No registered users and 6 guests