Suggestion for improving Heater fan

[Rob Glasgow]

At the recommendation of the group, I have added a 4" bilge blower to the fresh air duct. I have also added a speed controller to regulate the flow. Since the car is not complete, I don't know how effective the unit will be, but it certainly does move a lot of air so I expect it will be an improvement. I have painted the unit black.

This makes me wonder if I should do something to improve the heater fan unit. My original Smiths fan works and is in good condition, but doesn't put out much air. When in the defroster mode, there is only a suggestion of air movement out of the dash vents. It's always been inadequate. Has anyone found a way to improve on the original design? I have looked for a alternative fan and motor to install in the original Smith housing, but haven't found one to fit. I am considering another 3" bilge blower mounted in the engine compartment. Probably remove the Smith fan and motor, install a blanking plate over the opening and leave the housing in place.

Any ideas out there?

Here are some photos of my fresh air side.

 

[Chris_Masucci]

I was able to fit a GM blower motor to the Healey motor bracket. It moves about 100 times more air now. The Smiths motors just don't spin fast enough, new or old.

 

[steveg]

I was able to fit a GM blower motor to the Healey motor bracket. It moves about 100 times more air now. The Smiths motors just don't spin fast enough, new or old.

That is tantalizing - can you provide pictures? What model GM car was it from?

 

[RAC68]

Hi Rob/All,

In around 1967 and being my only mode of transportation, I found I could breath more air then my Healey's defroster could provide. Realizing the air flow provided by the Smiths fan was not that aggressive, I went to the salvage yard and secured a fan from a Oldsmobile Starfire convertible. Not finding the new blower installation that convenient, I extracted the electric motor and squirrel cage and fit it inside the original Smiths' bakelite housing. Wiring it in, I found a significant increase in heater/defroster air movement and it is still installed.

Today, I would suggest mounting a 3" bilge blower as a complement to the existing blower and install it out of sight with the same variable control you have used for the cold air duct blower. If the blower is mounted forward of the smiths blower, I would expect the bilge blower will provide sufficiently powered air flow to deliver additional volume even with the restriction of the second blower and even more if both were running.

Another approach would be to do as I have and replace the Smiths motor with a more powerful unit. Attaching a variable control would allow the on/off switch to remain functional but would provide additional speed variability.

My thoughts,

Ray (64BJ8P1)

 

[RAC68]

Rob,

Before you button up, I have some suggestions that I believe Steve Gerow can comment on.

As one who has favored the installation of a bilge blower and even wrote an article describing its installation, I can assure that a large volume of ambient air will be delivered when your Healey is MOVING FOREARD …even Slowly. However, due to the Healey’s porous radiator bulkhead, when stopped on a hot summer day, I would suggest you turn the blower off as hot air will be delivered.

I have discovered the reason for hot air being delivered when the car is stopped (i.e. traffic light, etc.) is relate to the reason our Healeys run hot and why we have compensated with aggressive fans and larger radiators. Air that is being drawn through the radiator is running into engine and finds less resistance escaping forward through such openings as the steering box. The warmed cooling air is then drawn, again, through the radiator and this cycle continues, producing hotter and hotter radiator cooling air. Since the cold air duct is just above the steering box, hot forward-escaping air is also drawn into the cold air duct by the bilge blower and delivered to the foot well of the car.

Again, if you are moving forward, even slowly, air passing through the grill will diminish or even eliminate this condition as the grill air will push all air rearward. So how do we address and correct this condition. The best way to address this condition, for both radiator cooling and cold air duct operation, is to seal openings in the radiator bulkhead and eliminate air from passing forward. However, this is only practical if your car is open as in the process of a restoration. Since my car is complete, adding panels to seal the radiator bulkhead would be quite difficult and, as a result, I have installed a single panel extending from just below the cold air intake, over the steering box opening, to the bottom of the grill and sealed between the left radiator duct panel to the right and the side access panel to the left, to eliminate a majority of the hot escaping air.

The above panel is attached to the lower lip of the radiator bulkhead just below the cold air duct and extends to the bottom of the grill. It is sealed to the radiator air director on the inside and to the access panel on the outer side. A small Styrofoam block was used to seal the cowl wiring passage.

Although this panel does provide improved cooling air, it is only a modest solution to the cold air duct hot air draw when stopped. I am still looking for a true solution and would appreciate any input.

Rob, since you have complete access to the radiator bulkhead, I would suggest you evaluate adding panels to close the bulkhead openings and, I believe, you would benefit from a cooler running and driving Healey.

All the best,
Ray (64BJ8P1)

 

[SideShifter Tri-Carb]

I just thought maybe they got the polarity wrong on the fan and it was running in reverse. So, these fans really do not perform well?

 

[Chris_Masucci]

That is tantalizing - can you provide pictures? What model GM car was it from?

I can't seem to find any pictures. It was your standard early 70's style blower motor. I had to pop the rivets out and so forth, and turn down the shaft to get the stock metal squirrel cage on but it works great. I spent $35 on it from ebay without the plastic thing.

https://www.rockauto.com/catalog/moreinfo.php?pk=86099&jnid=4&jpid=0

 

[steveg]

I can't seem to find any pictures. It was your standard early 70's style blower motor. I had to pop the rivets out and so forth, and turn down the shaft to get the stock metal squirrel cage on but it works great. I spent $35 on it from ebay without the plastic thing.

https://www.rockauto.com/catalog/moreinfo.php?pk=86099&jnid=4&jpid=0

I may get one of these. My couple-year-old Moss replacement fan motor for some reason draws a lot of voltage: the voltmeter goes from 13.5 to 12+ volts when I run the heater blower.

Headlights, driving lights and bilge blower together do not draw as much voltage.

 

[RAC68]

One last point. When I installed the upgraded Olds Starfire blower motor in my Healey, the additional volume of air created an unexpected situation. With the heater doors closed, my defoggers SING. Although this noise is not intrusive, it was unexpected and demonstrates the substantial improvement in FUNCTIONAL air flow.

A friend has created small transparent air directors, anchored under the dash vents, that keep air close to the windshield. When not needed, the directors snap down to block the openings. He has the original motor and, with the directors, sees no need to update the blower motor.

Ray (64BJ8P1)

 

[steveg]

I can't seem to find any pictures. It was your standard early 70's style blower motor. I had to pop the rivets out and so forth, and turn down the shaft to get the stock metal squirrel cage on but it works great. I spent $35 on it from ebay without the plastic thing.

https://www.rockauto.com/catalog/moreinfo.php?pk=86099&jnid=4&jpid=0

Chris/Ray - was the GM plastic squirrel wheel too deep or wide to fit in the Healey housing?

 

[RAC68]

Steve,

Yes. I wanted to keep the unit as original as possible for easier installation and fit so, as I remember, I cut the rivets and replaced them with screws and nuts. I created a motor mounting plate consistent with the original mounting and modified the shaft slightly to allow the installation of the original cage. Since squirrel cages and housings are usually designed as matched sets, I felt both must be used to gain the proper air flow benefits of the new motor. In all, the modification was quite easy and fast with the extraction and reinstallation of the completed blower under the fender being the most difficult part. Although I can't say I use the blower much, when considering it was from an American Oldsmobile Starfire manufactured around the same time and still working strong, I am glad I did the modification.

As far as the GM unit mentioned by Chris, as I understand it is a new and I would try to install the total unit, without modification. However, I would first see if I could get a unit from a salvage yard if I had any interest in modifying my original.

By the way, I am thinking of acquiring and installing a variable speed switch as with the cold air duct bilge blower. I am considering its installation just after the dash switch as the ground is mounted on the cross member under the fender mount. Initially I was thinking of installing a relay to feed the heater blower mounted close to the blower and fed by the line from the alternator close by. However, since the variable controller must be installed between the source and destination of power, this would require I route a controller extension all the way to the dash for convenient operation. Any ideas?

Ray (64BJ8P1)

 

[steveg]

...Initially I was thinking of installing a relay to feed the heater blower mounted close to the blower and fed by the line from the alternator close by. However, since the variable controller must be installed between the source and destination of power, this would require I route a controller extension all the way to the dash for convenient operation. Any ideas?

Ray (64BJ8P1)

Ray -
Earlier I was griping about the voltage drop on my voltmeter with the heater blower running. The harness supply wire is too thin. I jumped the motor directly from the solenoid connection and there was no voltage drop. Therefore will plan on installing a relay near the blower motor.

Would you put an inline fuse on a main power wire from a connection at the solenoid, or run a new, heavier wire from the same position on the fuse box as the current heater switch wire? The latter might be neater, as you could run the wire behind the harness.

BTW - RockAuto has these AC Delco motors starting at around $30 with and without the squirrel wheels.

 

[Keoke]

Add an additional wire of the same gauge as the existing one from the same position on the fuse box as the current heater switch wire.

THis is just another option.

OH!!
The characteristics of the lighting requirements and the blower requirements Suggest that separate fuses and power feeds be utilized for each.

 

[RAC68]

Steve,

I created an upgraded headlight harness that draws power directly from the alternator through a 20 amp fuse to feed 3 relays (high, low, and driver lights) using a 10 gauge main feed line. Since the alternator and fused line extend into the fender very close to where I would mount the heater relay, it would not be that difficult to create a branch, after the present inline fuse, to feed the heater. I would expect the 20 amp fuse and 10 gauge feed to be sufficient for blower and lighting requirements. However, I had thought of installing a relay to feed the horns as well and maybe a separate feed line for horn and blower relays would be more convenient using 2 separate inline or relay-incorporated fuses.

As you may realize, I am not shy when it comes to fuses and inline fuses allow me to incorporate specifically targeted protection while keeping it less then obvious. In my case, I would just install 2 more entries in my fuse directory.

I would expect the GM blower motor would be a good candidate. However, I would rather experiment with a salvage version before modifying a new final unit unless you know what alterations are necessary.

Ray {64BJ8P1)

 

[andrea]

At the recommendation of the group, I have added a 4" bilge blower to the fresh air duct. I have also added a speed controller to regulate the flow. Since the car is not complete, I don't know how effective the unit will be, but it certainly does move a lot of air so I expect it will be an improvement. I have painted the unit black.

This makes me wonder if I should do something to improve the heater fan unit. My original Smiths fan works and is in good condition, but doesn't put out much air. When in the defroster mode, there is only a suggestion of air movement out of the dash vents. It's always been inadequate. Has anyone found a way to improve on the original design? I have looked for a alternative fan and motor to install in the original Smith housing, but haven't found one to fit. I am considering another 3" bilge blower mounted in the engine compartment. Probably remove the Smith fan and motor, install a blanking plate over the opening and leave the housing in place.

Any ideas out there?

Here are some photos of my fresh air side.

Following your suggestion I have improved the air flow of other engine bay side
-placing the same powerful ATTWOOD 4000 4"diameter 10Cubic Meter/min(240CF/min) blower before the oldest, just near the generator-
cutting the pipe with a gap of around 8 cm-
The job for place the NEW BLOWER inside the pipes is not a joke - but after a long battle is possible
I have added the photos of the operation on a Google album
https://picasaweb.google.com/112770819864514987162/AHWORKSAndUPGRADEProject#
https://picasaweb.google.com/112770819864514987162/AHWORKSAndUPGRADEProject#6186118015340162690
Painted the New Blower BLACK is not immediately recognizable and at the first test results are very favorable - air pressure are good on foot area-only a a little air loss from the old blower case - NOW I need to finish the electrical connections -- and the adjustable DC motor speed
Thanks for your blower suggestion it is cheap an powerful

 

[RAC68]

Hi Andrea,

As always, a very nice installation. You mentioned using a 4" blower installed in the heater duct. Although you would have experienced a little loss in power, as I remember, the duct is only 3 1/4" in diameter and a 3" blower may have been a little easier to fit. However, your installation demonstrates your skill.

Great job,
Ray (64BJ8P1)

 

[andrea]

Hi Ray
I also was convinced that the operation can be impossible - my air pipes are the normal pipes sell by AH spares- but that 4000 blower have double air flow capacity than the 3000 following the same ATTWOOD quality and Tecnology - easy find by Amazon in UK
(reduced mail costs and no Customs duty, for me)
- Rob Glasgow photos encouraged me to tray-
as tradition, children less than 12 years old, learn a lot of new words, if transiting near my garage, during the pipes works -
BUT finally the blower fit the pipes,
I can encourage the same operation to anyone that want upgrade the oldest blower -My oldest is in work order and completely rebuild-
https://picasaweb.google.com/112770...ATIONAUSTINHEALEY10061958#5289011970858444434
https://picasaweb.google.com/112770...ATIONAUSTINHEALEY10061958#5290869469502606226
BUT probably I must dedicate more efforts to electrical engine -when stared a tremendous rattle came from, fortunately not audible at car movement,
and air flow are very limited, without any efficiency and benefit
Cheers

 

[Rob Glasgow]

After considering the various solutions, I've decided to install an Atwwod 4000 in the 4" portion of the heater duct. I will mount it on the fender well near the generator. I will most likely remove the Smiths motor and fan cage but leave the original housing. I will make a plate to cover the motor opening. I've ordered a wind speed meter and will take some measurements of the original fan and the new bilge blower, just for kicks.
I originally considered a 3" bilge blower mounted on the flat area right where the 3" duct enters the bulkhead,(Same place I mounted the 4" blower for the cold air side) but decided the incearsed output of the 4" blower was worthwhile. We shall see.
I haven't done anything about building shields to exclude hot air yet, but will do that before I mount the body.
I'll post some photos when I the fan is delivered and installed.

 

[andrea]

Finished the electric connections-
EASY- I have put one Double BULLET Connector -on place of the single, already present for the oldest blower-connected by wire and bullet the new blower, connected the ground wire to the nearest ground place.
NOW all two blowers works in tandem, rattles aren't audible with the car in movement- air pressure at the foot are very good, and I hope better with the car in movement (today raining here) and the DC motors Speed Control-
At moment I haven't any piratical pressure from the defrosts of windshield, BUT It isn't a problem I have the electrical heat defrosters for the winter
NOT jet finished the clamp works - I have 3x3" 160 clamps -No one 4" 161-Grrr!!!

 

[steveg]

Add an additional wire of the same gauge as the existing one from the same position on the fuse box as the current heater switch wire.

THis is just another option.

OH!!
The characteristics of the lighting requirements and the blower requirements Suggest that separate fuses and power feeds be utilized for each.

Yesterday I installed a relay next to the blower, with a 14ga supply wire. Am using the Charlie Hart fuse box and originally ran the wire from the same position as the heater switch (#3). This still showed some voltage drop as mentioned earlier, which I attributed to the smaller wire from the ignition switch to the supply side of the fuse box. Since I have only one horn, I reduced the horns' Buss fuse to 10A and attached the supply wire there. No more problem with voltage drop.

As a test, will go out somewhere and try blowing the horn with the heater blower running.

PS - the airflow still seems weak.

PPS - if 10A is too much fuse for the blower motor, will run the wire with a smaller inline fuse from position 'A' on the regulator, which is directly from the positive battery cable.