Blower(s)

[Mike Harry]

Im in the process of installing my fuel tank and blowers. I think there used to be one located near the back of the boat somewhere....? But I am thinking about installing 2 blowers.... both in the front of the boat to push the air instead of trying to pull it back. Would there be any downside to doing it this way? Is installing 2 better than one?

Some folks think it is unimportant how they are run, or if they run at all. Living on the river back in Alabama, working at my grandparents marina, I will tell you from what I have seen otherwise. I have seen at least 4 ski boats with damage due to complications during starting because blowers were not working properly, or were just not used.

Thanks for any help

[phil]

Seems to me that you have to have one in back because the hose connects to suck air out the rear vent on the transom. Ideal would probably be one blowing from the front and one sucking the air out through the hose and out the vent. Just blowing two fans in there without a hose attached to the rear vent isn't going to cut it IMO.

[Mike Harry]

I dont disagree with that at all. The whole reason I was looking at it that way is it appears there is not enough room to run the hoses (or a hose) behind the fuel tank, and without dropping the top back on the hull (which I really dont want to do but one time and that isnt now) I am not sure if there is room to run it in front of the tank with the board and seat installed as well. Possibly someone with an Advance could help a brother out ("JOEL") 

Thanks Phil. I think your correct

[RonT]

Without getting into the details of the regulations an Advance must have (1) 3" bilge blower drawing air from the lower third of the bilge and ducted overboard, and a natural air intake and natural discharge originating from the lower third of the bilge/engine compartment. Most of these had a blower mounted on the engine with a short duct to the bilge on hte suction side & then ducted via hose & pvc pipe to the transom & hose behind the tank up to the vent. The natural vent starts at the forward deck vent inlet, ducted into the bilge ahead of the drivers footwell, flow through the bilge to the back and discharges through a short piece of hose behind the tank connected to the rear vent. My test for EVERY boat coming into my shop is turn the blower on & feel by hand the air discharge coming out the rear vent, if none, repair. I recently did this on a 1996 Ski Nautique & found no discharge, but the blower was running. Found the vent hose smashed under the motor mount & exhaust, been that way since new! When I was writing the annual ski boat tests for WaterSki magazine in the early 90s I would always catch at least 4-5 boats every year with inop blowers, often with polarity reversed. Adding additional ventilation is never a bad thing, just make sure the OEM system is still working properly. 

[Mike Harry]

So, there are two holes in the top near the front (inlet) and two
holes in the top rear outlet. If I put a blower on one of the front (pushing) and one on the back (pulling) the other two can still be the natural flow pipes. Would this be sufficient?

[RonT]

As long as the aft blower you are installing is located or ducted to receive its air from the lower 1/3 of the bilge it would be fine. (Need to pickup the heavier gas fumes)

[Mike Harry]

Cool, on the floor just behind the motor it is then. Thanks

[Joel]

My blower is installed to the deck just under the port side exhaust riser...  Its a 3" blower...  It HAD a black hose duct connected to a white plastic PVC pipe in the rear bilge, connected again to another black hose near the rudder post that goes UNDER the gas tank & up behind to the rear vent...  Unfortunately, the black hose was disconnected from the PVC pipe.  It was in horrible shape, falling apart and disconnected from the rear vent as well.  The blower still pushes air out the vent, but not very efficiently...

The hoses coming in from the forward vent were also in disrepair...  Coming into the heater and all discombobulated (is that a word?) with hoses running everywhere...  I still havent figured them out...  Hopefully, the air coming into the forward hold is helping to circulate air through the bilge...  There was / is no forward blower...

How to replace the black hose vent BEHIND the gas tank is beyond me (without pulling the tank)...  Any help???

[Mike Harry]

Yeah, I got help for you...... pull the tank  thats the only way I can see it happening. Ive had my tank out for a few months, Im having trouble figuring out how the hose is going to go behind mine and the tank isnt installed nor is the top of the boat.

With that being said, Im thinking about hard pipe run down the transom to the floor and 90'd out from under the tank so I wont have to worry about the hose under their again.

[Joel]

If you can FIT a hard pipe with a rubber hose connection to the rear external vent cover - that would be great!  Your right - you wouldnt have to mess with this again.  With that said, you shouldnt need two blowers in a 19 ft boat that is also vented naturally.  The only reason it has a blower is because its gas powered.  The natural vents work quite well when installed correctly and the blower is for stray gas fumes collecting in the bilge (typically prior to starting).

The forward intake vent on the bow should bring in more than enough air to vent the bilge (especially underway) if the hose is installed correctly as Ron mentioned earlier (I'm gonna check mine today).  This is in addition to the blower sucking it up out of the bilge and blowing it out the rear external vent cover.  Mounting another blower in the rear would be good, but your gonna start running out of room back there pretty quick.  I'd ensure your natural venting is installed correctly and your blower is vented correctly as well.  Two blowers is overkill (which is fine) if you have the battery power and the space to do it...  Chances are the only space you'll find to mount a second blower is forward in the bow section with an intake hose from the forward external vent and an exhaust hose running into your bilge...  This may help to keep the engine running cooler with lots of fresh air forced into the engine compartment.  But it has to have the second blower to suck it out or the air wont MOVE very well.  The other option may be mounting a blower below the engine's stbd exhaust risers and an exhaust hose running back to the rear external vent.  Your boat is in pieces so if your gonna do it - now is the time    My blower just called it quits so I'm going to mount two - one in the forward bow (as mentioned above) and replace the port side blower with some new hose vent to the pvc pipe...  not sure what I'm gonna do about the aft hose behind the tank.

[Mike Harry]

That's pretty well what I'm thinking. I've got the extra blower, and plenty of room up front with unlimited access.

[Joel]

You should have three black air duct hoses coming in from the forward vent (thats what mine has).  They are located in the forward bow area ahead of the driver on the stbd side.  I think one was supply for the heater and the other two for natural ventilation...  I took the heater out because the heater core was leaking and much to my surprise NONE of the supply hoses were connected to the heater.  After removal, I discovered that NONE of the hoses were routed into the bilge either - they were just lying in there in a jumbled mess.  After some crawling around & twisting like a 210 lb pretzel I found two EMPTY round holes in the floor (directly under where the heater was installed) on the stbd side of a centerline bulkhead.  I took two hoses and shoved them into the bilge holes (both are a tight fit).  I left the third hose in the bow area to provide fresh air for my gear.

Gonchuan is rebuilding his boat so he wont have this problem, but some of you may want to check your ventilation hoses since God only knows who's been under there last and what work they did, OR DIDNT, do...  We keep learning more with each day   

[Mike Harry]

Man, that is a mess....... I guess I am the lucky one alright never have had my boat in the water or anything

Just being a smart ass man, hope you figure it all out........ hope I figure it out sooner rather than later myself!

[Joel]

Thats why we post this stuff... so everyone else doesnt have to figure it all out (again) by themselves...     Good luck on the project!!!

[Mike Harry]

Well, some wont like this post..... but its my boat and my azz so Ill post what I have come up with. Starting from the exhaust port in the back of the boat I put a 3" to 2" rubber adapter (so I can clamp directly to the exhaust "nozzle"). 2" pvc down to the the floor behind the tank with a 2" 90 degree angle toward the front. A short peice of 2" pipe into a 2" to 3" adapter (pvc this time) and a 3" nipple (short piece of pipe) to connect the hose to.

I found that I dont have enough room for a 3" piece of hard pipe behind my tank, so I went with 2". With the added blower in the front pushing air through the other rear hole. I hope I will be safe enough.