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Suggestion for improving Heater fan

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Hey guys, is there any update on this? I just ordered the 4" Attwood bilge blower for the cool air. Is that approach working well for you? What about the heater side? Another Attwood blower or a did the chevy motor work as a replacement for the Smiths?
 
Dale, the Atwood bildge blower works well on the drivers side. I installed it with an adjustable controller so I can vary the speed. I got the car back on the road in December so I haven't tested it in warm conditions. Remember, this is not an air conditioner so the best you will get is rapidly moving warm air. I did make up an interior tube from foil coated bubble wrap insulation which I inserted in the normal air duct on the drivers side, hoping to minimize the heat transfer to the incoming air.
I did test the same bilge blower on the heater side and took air speed readings using a hand held wind meter. That's as close as I come to doing scientific measurements. The bridge blower alone did not product any more wind speed than the Smiths blower through either the floor or defroster outlets and only marginally better when placed in series with the original. I chose to go back with the Smith unit.
BTW, I did get much better air flow on the drivers side by removing the small screen that covers the opening in the cockpit above you're feet.
 
Thanks Rob. Good stuff. The bubble wrap is an interesting idea. I ended up purchasing the air tube from Tom's Import Toys. It arrived today. It's much heavier than the original tubing. I'm hoping that'll help.

I'm not expecting AC, just some airflow.
 
There's a previous thread on the subject of hot air coming in through the fresh air tube.

I maintain that insulating the air tube isn't the answer because the real problem is hot air being recirculated from the exhaust area forward to where it's sucked into the fresh air intake. You need to block that air. Also somehow extending the intake forward to directly behind the grille can help.

Here's the gallery for my air-control project:
https://www.pbase.com/stevegerow/healeyaircontrol
 
Hi Dale,

Steve has it right, the cold air duct fan works great if you are moving but will suck in air already warmed by passing through the radiator when you are stopped (i.e. traffic light, etc.) unless you have fender vents or hood louvers installed. I had designed a panel to help eliminate the recirculated hot air (presented near the beginning of this thread) but it is only marginally successful. Since it is almost impossible to seal the radiator bulkhead I am also thinking of installing an enclosed reasonably sealed path from the grill to the radiator and extending the cold air tube to the side of the enclosure near the grill with a mild scoop directed forward. The hot air issue is only present when the car is stopped and not when radiator exhaust is pushed back as the car moves forward...but you need the fan most when the car is stopped.

One other way to limit hot air in the foot well is to find a way to stop the blower when the car is in neutral and the brake lights are on. However, although this could significantly reduce adding hot air into the foot well when stopped, it doesn't give you any additional cooling at that time on a hot summer day that the original non-powered system provides.

And the project continues.
Ray(64BJ8P1)
 
Excellent work Steve.

I understand Ray. Thanks for the explanation.

I'm grateful that you guys are ahead of me on this one. My wife recalls the hot (meaning uncomfortable:eek:) rides when we were teenagers. She sees the bills for this restore. I keep her happy by offering; convertible top, insulated cabin, and getting out to meet Healey people. Maybe this year!
 
Dale, Heat Insulation and sound deadening material applied to the entire inside of the cockpit (i.e.Hush Mat or Dynamat) will improve the experience greatly.
 
Thanks guys. My wife is getting happier by the minute.

Rob,
I did put down some material that's very close to dynamat. I'm thinking of covering that with a closed cell 1/4" foam.

I thought about a scoop for the air intake. Take a look at the air tube that I bought from Tom. Tough stuff. Note that the pic shows two tubes, one inside the other. Why not get a couple of flanges (see Moss pic) and use the heavy duty tube connected to the air intake out to the grill? I'm not sure how the flange would connect to or near the grill but that could be worked out. Thoughts?
 

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Rob/All,

Getting back to when a Bilge Blower is beneficial and when a Squirrel-Cage blower is better. The Bilge Blower fan is used when minimal restrictions are within the path of the air flow and air speed is beneficial. The Squirrel-Cage blower is best when restrictions or incumbrancers are encountered in the flow path.

The Bilge Blower was selected for use in the cold air duct to move outside cool air through a relatively straight path as quickly as possible to the cabin to minimize exhaust-radiated heat being absorbed by the delivered air. The heater tube was designed with a Squirrel-Cage blower to move a volume of air through a heating matrix at a speed slow enough to absorb heat. The Squirrel-Cage blower is much more tolerant of backpressures caused by such incumbrancers as the heater matrix and defrosters vents and will deliver relatively constant air volumes at selected motor speeds.

Placing a Bilge Blower fan in front of a Squirrel-Cage blower result in the Bilge Blower seeing the Squirrel-Cage blower as a major restriction, causing backpressure resulting in a slowed disrupted air stream delivery to the Squirrel-Cage blower. As a result, the air delivered by the Squirrel-Cage blower diminishes in air volume and speed.

Hope this helps explain your experience,
Ray(64BJ8P1)
 
RAC68, thank you for the clear explanation of the two types of fans. It was warm enough yesterday to try out the bildge fan on a short drive and I am happy with the results. I'll have to wait a bit to try it out in 90 degree heat to see how effective it is in those conditions.
 
That's the same unit I used. Works great. I mounted it just above the drivers side foot well panel and made a simple bracket to mount the knob below the wiper motor bracket.
 
These are all great ideas! The only thing I can add is that I moved my vent hose to the top of the footwell. My limited aerodynamic knowledge says whenever air has to turn 90 degrees is the same resistance as adding 10 feet of hose. I also want it to hit my feet. Adding a bilge blower when stopped will be my next project.
The other thing I'm doing is putting airDSCN4150.jpgIMG_3897.jpgDSCN2727.jpgDSCN2752.jpg ducts behind the grille like similar to the rallye cars. Instead of forcing more air to the radiator, it will force more air to the duct. This will also do the same thing as previously suggested that will block engine air from coming back around and into the vent when stopped in traffic.
 
Chris or anyone that has knowledge,

I'm using your suggestion of an ACDELCO heater blower motor in place of the smiths attached to the squirrel cage. The ACDELCO has a cooling tube connection. Did you hook that up to the squirrel cage box or air tube, or did you just leave it?

Thanks, Dale
 
RestoreThemAll said:
Chris or anyone that has knowledge,

I'm using your suggestion of an ACDELCO heater blower motor in place of the smiths attached to the squirrel cage. The ACDELCO has a cooling tube connection. Did you hook that up to the squirrel cage box or air tube, or did you just leave it?

Thanks, Dale
Click to expand...

Questions: Do you have a PN on the AC Delco blower? Not sure what you mean by cooling tube - did you do something other than install the AC Delco blower in the stock housing?
How about a picture.
 
What's a PN?

I modified the mounting plate of the ACDELCO to fit on the smiths squirrel cage box, and turned the shaft down to 1/4" so the Smiths cage will fit on. GM put a cooling tube on the blower motor to help cool it. It normally runs to the box where it can pickup air from the blower. I'm not sure if it needs that much cooling with this application. No AC for instance.

I'm also adding the variable speed switch to slow it down if I need to. One for the bilge blower on the fresh air, one for the heater.

The attached pic shows the progress so far. BTW it puts out a lot more air than the Smiths.
 

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