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MontreAl

Engine Room Blowers

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Neither of my 2 ventilation fans work. In both cases when the switch is on there is power to the motor. I am trying to source the motors.

I have Jabsco Model 35440 blowers fitted with Fasco 2807-513-121 motors.  I can buy the blower complete but can't find the replacement 12V motors, which is all I need.

Any suggestions?

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2 minutes ago, Phillbo said:

Odd that both motors would fail at the same time....

They didn't actually.  I was running on one blower for a while and then when the second one quit I decided it was time to do something about it.

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As your originals both failed, I would not replace them in kind. Attwood, Defender, Johnson Pump, Sea Flow and a host of others make both 3" and 4" in-line replacements. I prefer Attwood and it would seem we have some "Defender Defenders".     Just check amp rating to confirm you are fused and wired correctly, but in my experience they all draw about the same.  W

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Remember the requirement of the USCG  for sizing the blowers.   Also some companies put the end of the suction hose  where ever they feel like & it is quicker & cheaper.  I relocated with longer suction hoses to suck at the centerline of the hull. Location where the heavier fumes are found LAST.  That way you are really emptying the fumes if a small spill occurs.  This is one time where much bigger is really much better.

You will need to do a Wingnut check of wire size & fuses...……… Wire size is very important .  THAT will determine maximum amount of continuous current the motor can draw from the battery. Adjust the fuse size for the motor need.

Edit

2 items that do save lives.  Bilge blowers an 2 bilge pumps...……………… They can & do sink boats if they are not working.

 

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3 hours ago, cyclops2 said:

Remember the requirement of the USCG  for sizing the blowers.   Also some companies put the end of the suction hose  where ever they feel like & it is quicker & cheaper.  I relocated with longer suction hoses to suck at the centerline of the hull. Location where the heavier fumes are found LAST.  That way you are really emptying the fumes if a small spill occurs.  This is one time where much bigger is really much better.

You will need to do a Wingnut check of wire size & fuses...……… Wire size is very important .  THAT will determine maximum amount of continuous current the motor can draw from the battery. Adjust the fuse size for the motor need.

Edit

2 items that do save lives.  Bilge blowers an 2 bilge pumps...……………… They can & do sink boats if they are not working.

 

Knowing about how gas fumes collect at the bottom (or the lowest point) because their density is heavier than air, and so they'll collect at the lowest points of the bilge or wherever they accumulate and from what I've seen, most of the locations that Chaparral installs their blowers are too high to be as most effective as possible to pull out the majority of them, even with the hatch closed.  The vents introduce too much fresh air along with all the other nooks and crannies boats have that I marvel at how mine would even have a chance to work being located on the top shelf of the bilge.  No where near the gutter keel.  So positioning them in the best spot to give them the best chance of sucking out any fumes is a good thing.  I'll post a pic of where mine are located later and it's laughable.  Unless they know something I don't but being at least a foot higher than the keel and facing straight forward doesn't seem to make much sense.

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23 hours ago, MontreAl said:

Neither of my 2 ventilation fans work. In both cases when the switch is on there is power to the motor. I am trying to source the motors.

I have Jabsco Model 35440 blowers fitted with Fasco 2807-513-121 motors.  I can buy the blower complete but can't find the replacement 12V motors, which is all I need.

Any suggestions?

As already suggested ...

7 hours ago, Wingnut said:

As your originals both failed, I would not replace them in kind. Attwood, Defender, Johnson Pump, Sea Flow and a host of others make both 3" and 4" in-line replacements. I prefer Attwood and it would seem we have some "Defender Defenders".     Just check amp rating to confirm you are fused and wired correctly, but in my experience they all draw about the same.  W

Replaced the noisy and power hungry Jabsco blowers (12-14A each) with inexpensive compact Attwood blowers (3-4A each) and you will get a similar CFM rating with less noise. Go with waterproof version, 3" or 4" as applicable to your install. The blower hoses should go to the lowest place in the bilge ... not just somewhere in the engine compartment ... somewhere under the engine. Consider replacing and/or rerouting all vent hoses as well.

Two discussions about It ...

 

Hope this helps ...

 

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Honestly, I'd rather they be noisy (or a better word is loud) so I can remember they're on and make sure I shut them off.  Countless times I've driven off with the blowers running for at least another 10-15 minutes because the 8.1 just overpowers them and the only reason I remember to shut them off is I either notice the lights are still on the rocker switch or my wife says "sounds like blowers are still on."   I say the louder they are, the better for this guy who isn't getting any younger and who's hearing is definitely deteriorating with age.  I'm sure all those Judas Priest and AC/DC concerts didn't help.  Or the days playing in a hard rock band! :D

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18 hours ago, Richard W said:

As already suggested ...

Replaced the noisy and power hungry Jabsco blowers (12-14A each) with inexpensive compact Attwood blowers (3-4A each) and you will get a similar CFM rating with less noise. Go with waterproof version, 3" or 4" as applicable to your install. The blower hoses should go to the lowest place in the bilge ... not just somewhere in the engine compartment ... somewhere under the engine. Consider replacing and/or rerouting all vent hoses as well.

Two discussions about It ...

 

Hope this helps ...

 

The blower hoses should go to the lowest place in the bilge ... not just somewhere in the engine compartment ... somewhere under the engine.  Builders seem to have two schools of thought here. A properly designed bilge evacuation system needs both inlet venting and outlet discharge induced with the help of the blower system. The most efficient blower on the boat is the engine itself as when it's running it is moving far more CFM than any blower ever will. To that end, many boats including Chap puts a simple pair of hoses from the gunnel fresh air inlet, down into the bilge space below the engine. This way anytime the engine is running, cool air is being sucked into an area below the oil pan, then up across the engine and into the air intake creating a continuous scavenging effect reducing both heat and fume accumulation. At idle speed, and/or before start-up an energized blower will induce flow through this intake hose as long as the engine hatch is closed and then discharge the stale air overboard. Placing the blower suction hose higher in the bilge space eliminates dead zones as air exits the low end of the inlet hose, sweeps up around the lower half of the engine bay, and is then sucked up by the blower suction hose. At WOT with the hatch down and the blowers off, you will actually notice a reverse flow happening within the blower. Every boat is different but I give the builders a little more credit and like to feel that some level of design criteria was incorporated into their hose routing scheme. W

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9 hours ago, Wingnut said:

The blower hoses should go to the lowest place in the bilge ... not just somewhere in the engine compartment ... somewhere under the engine.  Builders seem to have two schools of thought here. A properly designed bilge evacuation system needs both inlet venting and outlet discharge induced with the help of the blower system. The most efficient blower on the boat is the engine itself as when it's running it is moving far more CFM than any blower ever will. To that end, many boats including Chap puts a simple pair of hoses from the gunnel fresh air inlet, down into the bilge space below the engine. This way anytime the engine is running, cool air is being sucked into an area below the oil pan, then up across the engine and into the air intake creating a continuous scavenging effect reducing both heat and fume accumulation. At idle speed, and/or before start-up an energized blower will induce flow through this intake hose as long as the engine hatch is closed and then discharge the stale air overboard. Placing the blower suction hose higher in the bilge space eliminates dead zones as air exits the low end of the inlet hose, sweeps up around the lower half of the engine bay, and is then sucked up by the blower suction hose. At WOT with the hatch down and the blowers off, you will actually notice a reverse flow happening within the blower. Every boat is different but I give the builders a little more credit and like to feel that some level of design criteria was incorporated into their hose routing scheme. W

Certainly, every boat is different ...

My Chap as built had two outlet hoses terminated in the bilge under the engine near transom and the inlet hose in the bilge in front of the engine, under water pump and balancer. Looked to me like at least adequate if not just right placement which works in either case, under power and when moored.

What was not adequate is the fact that all three vent hoses were connected to the vents on starboard side ... all three vents are under one large cowling. This inadequate install ensures undesired circular air flow under many circumstances. Things like this call for a review and potential rerouting of engine room vent hoses on every Chap boat.

... every boat is different and that's a problem.

Things like this should be functional and consistent on every unit built.

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On 11/8/2019 at 6:53 AM, Wingnut said:

As your originals both failed, I would not replace them in kind. Attwood, Defender, Johnson Pump, Sea Flow and a host of others make both 3" and 4" in-line replacements. I prefer Attwood and it would seem we have some "Defender Defenders".     Just check amp rating to confirm you are fused and wired correctly, but in my experience they all draw about the same.  W

Yep!

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On 11/8/2019 at 7:08 PM, Hatem said:

Honestly, I'd rather they be noisy (or a better word is loud) so I can remember they're on and make sure I shut them off.  Countless times I've driven off with the blowers running for at least another 10-15 minutes because the 8.1 just overpowers them and the only reason I remember to shut them off is I either notice the lights are still on the rocker switch or my wife says "sounds like blowers are still on."   I say the louder they are, the better for this guy who isn't getting any younger and who's hearing is definitely deteriorating with age.  I'm sure all those Judas Priest and AC/DC concerts didn't help.  Or the days playing in a hard rock band! :D

You can install a LED indicator light to show that there on.  

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On ‎11‎/‎9‎/‎2019 at 8:39 AM, Wingnut said:

To that end, many boats including Chap puts a simple pair of hoses from the gunnel fresh air inlet, down into the bilge space below the engine.

Have you (or anyone else) seen fresh air hoses on their Chaparrals run from the inlet vents to below the engine?  I've never seen that on any Chaparral or any other boat, for that matter. 

On ‎11‎/‎9‎/‎2019 at 8:39 AM, Wingnut said:

Placing the blower suction hose higher in the bilge space eliminates dead zones as air exits the low end of the inlet hose, sweeps up around the lower half of the engine bay, and is then sucked up by the blower suction hose.

So you're saying that since I don't have ANY hoses running from the vents to under the engine, that it's better to hook up a pair of hoses from the portside vents and run them all the way down to under the engine and leave the blowers in their current location up on top of the higher bilge shelf as in the picture?  Look how high and how far back these things are.  I find it hard to believe that they are positioned to be as effective as possible.  And I have NO vent hoses coming from my portside inlet or dedicated gunnel hole or anything like that.  This seems strange that they would work well.

ts3rboK.jpg

That seems ridiculously high and way back also.  Perhaps being way back might have a good reason for it since with the boat sitting in the water, the back end near the transom is in fact the lowest point for the fumes to accumulate.  But I'm no expert by any stretch of the imagination, but I have enough knowledge and common sense to see that and think how the heck are those two blowers, in this current configuration be able to pull any gas fumes that accumulate below the engine?  There are no hoses that run from the open vents on the other side to below the engine like you mentioned but instead of doing that, I was just going to add extensions to the 2 blowers and get them under or at least turned around the corner on that top shelf and face down to the lower bottom of the bilge.  I think that would help pull out the fumes (if the even exist) much better than the current configuration.

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Let us all remember the possible " Station wagon effect "  .  At various wind and on plane speeds.  Getting rid of a slow gasoline leak & the fumes from it. Is not a quick deal.  Testing with some gas in the bilge & test equipment is required.   We have to depend on boat companies to take the time & do it right on each boat type.   A really tough cookie to do right.

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