[C320-list] Starting new chat about Engine vents

[Jeff Hare]

Hi Scott, 

We used to have 12v cigarette outlet but converted it to a dual USB charger plug instead.

Again, depending on your battery configuration, the engine pod (not the nav instrument pod) *might* be powered by your starting battery instead of house battery.  In that case, if you wanted a USB charger plug or 12v adapter in the engine pod, you'll want to consider a few things:

1. USB charger ports (not true for the 12v cig adapter) typically have about 1ma standby current draw when powered and nothing is plugged in.
2. Factory wiring kills power to everything in the engine pod when the key is turned off.  We always turn off the key when under sail.

So, you could connect the USB charger port to the supply side of the key-switch,  pass it through the push-button blower breaker, then to the blower switch and finally power the USB charger.  Use the same size wire for the supply and ground and be sure that they are sized to handle 10amps (or whatever the breaker is sized at).  

Now you have a protected USB (or 12v adapter) that you can turn on or off regardless of the key switch position.  

Pretty simple arrangement that reuses all the blower stuff and properly protects the wiring from a short. (Most important when you're using a 12v adapter, but a good idea in both cases).

-Jeff Hare 

-----Original Message-----
From: C320-list [mailto:c320-list-bounces at lists.catalina320.com] On Behalf Of Scott Westwood
Sent: Friday, February 9, 2018 7:23 AM
To: C320-List at Catalina320.com
Subject: Re: [C320-list] Starting new chat about Engine vents

Again, I can't say enough about the things I can learn from this group.  Many thought triggers.
FWIW:  Sounds like my plan will be to remove all those hoses and the blower.  I never liked those plastic hoses and I was planning to replace them.  They get brittle so you can't always see holes/slits and they are taking up room.  Removing all that mess and letting a maintenance free system do the same thing makes sense to me. (personal preference)  Sounds like it will also help the compressor compartment too.  New project before Easter.  Yeah!!!!
Now what to do with the blower switch on the panel?  I need (would like) a 12v cigarette outlet at the helm for cellphones etc...  Maybe round out that hole?  Thinking on that one.  Low, and plug could stick out far enough to interfere with wheel??   Save drilling another hole in the new navpod.  Also easier to run new dedicated wire there than the almost full navpod channel.  Makes the panel "not original" but.....  Have not thought long on this one.  Want it on the navpod but.... Way down on the list.
 
Thanks,
Scott Westwood scottwestwood at bellsouth.net H (919)-362-8538     C (919)-618-7185 

      From: Warren Updike <wupdike at hotmail.com>
 To: "c320-list at lists.catalina320.com" <c320-list at lists.catalina320.com>
 Sent: Thursday, February 8, 2018 3:14 PM
 Subject: Re: [C320-list] Starting new chat about Engine vents
   
Some years ago, after replacing the blower, I changed the blower connection on the key switch so it's switch was always powered. I did this so I could run the blower a while after I killed the engine. The air expelled is warm, certainly not hot. I also had extended the hose going to the blower, forward in the engine space behind the alternator with the thought that would help keep the alternator running cooler (a substantial amount of output is lost as the ambient temp rises.) 

Also, I do prop the port lazarette open most of the time to allow the heat from the compressor to escape. There is/was an enhancement accessory that included a cowl to install on the output side of the heat exchanger (radiator) with a flex-hose to allow the heated air to be ported overboard. I haven't done this. I'll see if it is still available.

I don't think it makes a lot of difference whether I run the blower or not; and, it is important to vent the compressor space. So, Jeff's suggestions all seem reasonable. 

While reading this thread, it occurred to me that the engine consumes so much air from the space that more of the warm/hot ambient air goes through the engine than is moved overboard by the blower. 

This is a great project that can produce real payback. Just reducing the duty cycle of the compressor extends the life of the compressor, it also reduces the draw on our precious house bank. 

So, as anyone makes the effort to implement these ideas, please do keep us all informed. It's a great topic for the Mainsheet.

Warren and Pattie Updike (Mainsheet Technical Editor)
1994 C320 "Warr de Mar" #62
Middle River, Chesapeake Bay

-----Original Message-----
From: Jeff Hare [mailto:Catalina at thehares.com]
Sent: Wednesday, February 07, 2018 2:33 PM
To: C320-List at Catalina320.com
Subject: Re: [C320-list] Starting new chat about Engine vents

That was my suggestion earlier back when I first did it.  I thought it would be a good idea, but it was so loud it was just impractical.

Instead, I considered reusing the blower switch for a light or some other purpose in that back locker since it was already wired there.  The main drawback to the blower that for some of us with dedicated starting batteries is that the power feeding the engine pod/blower is from the starting battery, not the house bank. It would take a little rewiring to get house bank power up in there.  So there's yet another reason my blower is destined for the basement.

-Jeff

-----Original Message-----
From: C320-list [mailto:c320-list-bounces at lists.catalina320.com] On Behalf Of Graeme Clark
Sent: Wednesday, February 7, 2018 2:26 AM
To: C320-List at Catalina320.com
Subject: Re: [C320-list] Starting new chat about Engine vents

Great ideas Jeff

I had heard an alternative suggestion somewhere, to keep the blower but shorten the hose so it sucks air from the fridge compressor area to help cool it

Seems a reasonable idea apart from noise and yet more current drawn off the batteries!
Graeme



Sent from mobile: please excuse typos etc.!


> On 7 Feb 2018, at 03:33, Jeff Hare <Catalina at thehares.com> wrote:
> 
> Here's the rationale behind my choice, and I'll bullet them a bit.
> 
> 1. USCG regulations I've seen say a Bilge blower isn't required for a
diesel engine anymore.  The one on the 320, especially with how it's installed, doesn't move enough air in practice to really vent much of anything out of the engine space. Especially using those restricted dryer vent hoses.  And also it's embarrassingly loud and obnoxious as heck when running.
> 
> 2. If you look at that aft locker space as a whole, the air intake on 
> the
engine mostly draws fresh air through the path where those white hoses run.
The bulk of the air feeding the engine probably doesn't come through those undersized hoses at all. The one that was supposed to be used to feed air to the engine is the one connected to the starboard side vent.  That long bendy path to the starboard side vent is pretty useless for that purposes.
> 
> 3. If you were to look at the resistance involved in sucking air 
> through
those bendy collapsed hoses, you'd realize that air would flow more freely to the engine without them at all.  
> 
> 4. The Aft locker area is also where the fridge compressor is. If you 
> run
your fridge a lot,  that area heats up and makes the compressor work harder than it would if it had fresh air available. That's why if you slightly prop open the port aft locker and vent the heat from the fridge, it'll run a bit less.
> 
> 5. Removing those hoses reduces clutter.
> 
> So: I figured, why not make these systems work as efficiently as we 
> can by
allowing compressor heat to rise and exit the vents on their own without any hoses blocking the vents.  When the engine is running, fresh air will be drawn in through the vents and cracks, pass through that aft locker, under the port locker where the white hoses used to run and into the engine.
Since the engine draws quite a bit of air, it'll maybe draw some of the excess fridge heat with it as well.  
> 
> I'd clamp a scrap of window screen over the inside of the vent holes 
> will
keep the critters out without being overly restrictive for airflow.  I did all this when I replaced my fuel tank and it cleaned up the appearance of that space quite a bit. 
> 
> To answer your other questions:
> 1) Yes we leave the aft berth boards and bed in place when motoring.  
> In
fact, I would advise that you not run the engine in gear with the board directly behind the engine off.  The spinning shaft can spray a line of mist/water that could mark your ceiling in some cases.  Look at your muffler right in line with where the shaft enters the stuffing box and see if you see evidence of any spray line. The PSS shaft seal left a black line on ours from carbon/water and it's also on the underside of that board.
> 
> 2) A CO sensor is a wise choice, especially since we have a propane stove.
While CO isn't quite as big a concern with diesel exhaust as with gasoline, diesel exhaust still dangerous if there's a exhaust leak and a CO sensor in the aft cabin is wise.
> 
> -Jeff Hare
> 
> 
> 
> -----Original Message-----
> From: C320-list [mailto:c320-list-bounces at lists.catalina320.com] On 
> Behalf
Of Scott Westwood
> Sent: Tuesday, February 6, 2018 4:01 PM
> To: Catalina List <c320-list at catalina320.com>
> Subject: [C320-list] Starting new chat about Engine vents
> 
> I saw Jeff's comment about the engine vents and those bendy hoses.  I 
> just
redid my engine instrument panel and replaced the Blower switch.  Have not re-installed the panel yet so I have no idea if the blower even works.  So this means I have not really been "venting" the engine compartment at all.
Does not seem to have been any problems (so far- knock wood).  I was planning to go over all that once I got the panel back in place.
> Are you saying that you took out those (we have) white flexible hoses 
> that
seem brittle to me.  It sounds like you (Jeff) removed the hoses and put screen (for critters) over the stern holes??  Do you run the engine with the aft berth boards all in place?  Do you leave anything else open?  Or... does the engine compartment vent enough with all the covers on??
> FWIW.  We plan to (have not been) keep a battery operated Carbon 
> Monoxide
sensor with us on the boat just as a safety feature.  Portable and you can take it along with you anywhere. Thanks, Scott Westwood scottwestwood at bellsouth.net H (919)-362-8538     C (919)-618-7185  
>