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RestoreThemAll
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Suggestion for improving Heater fan
- Thread starter Rob Glasgow
- Start date
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Above there are pictures of clean installations of bilge blowers where their bases are bolted to the foot box just in front of the firewall flange.
In the event of a blower failure, that would require removing the fender in order to remove the blower.
Suggest making a stub out of aluminum flashing and clamping it to the flange. The hose clamps can be angled for access from the engine compartment. Carbs and (maybe) intake manifold would have to be removed, but not the fender.
Apologies for the funky photo - just got done removing the base feet and haven't yet painted it.
In the event of a blower failure, that would require removing the fender in order to remove the blower.
Suggest making a stub out of aluminum flashing and clamping it to the flange. The hose clamps can be angled for access from the engine compartment. Carbs and (maybe) intake manifold would have to be removed, but not the fender.
Apologies for the funky photo - just got done removing the base feet and haven't yet painted it.
Last edited:
RAC68
Darth Vader
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Hi Steve,
Good thought for those not concerned with hiding the blower. Didn't you mount your cold air bilge blower toward the front of the duct? To me, that would be even better for easy access.
Chuck94.... posted his cold air duct that he made a port for directly into the foot well and blocked of the original vent. This makes a lot of sense to me if you are not against having permanent modifications.
However, in all these cases, we still have the issue of hot engine radiator air being recirculated and sucked in by the cold air vent. Steve, you have done quite a bit of work sealing your radiator bulkhead. I would be interested hearing about your cooling experiences after sealing the cold duct entry from hot recirculating radiator cooling air.
Ray(64BJ8P1)
Good thought for those not concerned with hiding the blower. Didn't you mount your cold air bilge blower toward the front of the duct? To me, that would be even better for easy access.
Chuck94.... posted his cold air duct that he made a port for directly into the foot well and blocked of the original vent. This makes a lot of sense to me if you are not against having permanent modifications.
However, in all these cases, we still have the issue of hot engine radiator air being recirculated and sucked in by the cold air vent. Steve, you have done quite a bit of work sealing your radiator bulkhead. I would be interested hearing about your cooling experiences after sealing the cold duct entry from hot recirculating radiator cooling air.
Ray(64BJ8P1)
RestoreThemAll
Jedi Warrior
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I recently installed a bilge blower exactly like Rob shows at the beginning of this thread. I tested it and it works great. When I turned it on I noticed that the air was coming out of the bottom of the box in the cabin underneath the circular screen. The screened vent directs air horizontally and there is a rectangular hole under it that directs air vertically down to the dim switch where my feet will be one day. With this extra hole I left the screen in the original vent to keep a little resistance. It works perfectly. I'm going to assume, based on others comments, that the 2nd hole is a non original modification. I've owned the car since the early 1970s and can tell you that I did not cut the 2nd hole. I'm also not going to cover it.
I have not dealt with the hot engine air pulling into the cool air vent. Tried and true success in that area would be well received.
I have not dealt with the hot engine air pulling into the cool air vent. Tried and true success in that area would be well received.
RAC68
Darth Vader
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Hi Dale,
You will find that as long as you are traveling forward at a reasonable rate of speed, hot recirculating radiator air is not an issue. It only happens at NO or very Low speeds (i.e. parades, stop lights, etc.) where the air passing through the radiator finds it easier to flow forward around the steering box and is sucked in by the bilge blower. This was not an issue when not having a bilge blower because air flow would only take place when sufficient outside air was PUSHED into the cold air duct as a result of forward motion.
You will also find that the air coming out of the cold air duct flows up and toward the back of the dash and a deflector mounted on the bottom of the wiper motor mount will be beneficial in directing the air flow down toward your feet.
Although I have been very early in the implementation of using a bilge blower to power cool air ventilation within the cabin, I must admit I was not cognizant of the radiator hot air recirculation problem. As a result, its operational benefit...for me... for keeping cool during July 4th parades and summer Shore traffic has been greatly diminished. My objective now is to find a reasonably simple way to eliminate the hot air recirculation issue in a completed Healey.
Ray(64BJ8P1)
You will find that as long as you are traveling forward at a reasonable rate of speed, hot recirculating radiator air is not an issue. It only happens at NO or very Low speeds (i.e. parades, stop lights, etc.) where the air passing through the radiator finds it easier to flow forward around the steering box and is sucked in by the bilge blower. This was not an issue when not having a bilge blower because air flow would only take place when sufficient outside air was PUSHED into the cold air duct as a result of forward motion.
You will also find that the air coming out of the cold air duct flows up and toward the back of the dash and a deflector mounted on the bottom of the wiper motor mount will be beneficial in directing the air flow down toward your feet.
Although I have been very early in the implementation of using a bilge blower to power cool air ventilation within the cabin, I must admit I was not cognizant of the radiator hot air recirculation problem. As a result, its operational benefit...for me... for keeping cool during July 4th parades and summer Shore traffic has been greatly diminished. My objective now is to find a reasonably simple way to eliminate the hot air recirculation issue in a completed Healey.
Ray(64BJ8P1)
Dale,
Does the new GM blower mounted in a Smiths fan box blow hard enough to need speed reduction? Years ago, I mounted an extra Smiths fan in the bracket on the driver side to aid cool air movement, with disappointing results. I am interested in your modification to increase air flow. How did you reduce the shaft to fit the cage? I'm not an engineer or a mechanic...
Douglas
Does the new GM blower mounted in a Smiths fan box blow hard enough to need speed reduction? Years ago, I mounted an extra Smiths fan in the bracket on the driver side to aid cool air movement, with disappointing results. I am interested in your modification to increase air flow. How did you reduce the shaft to fit the cage? I'm not an engineer or a mechanic...
Douglas
OP
Rob Glasgow
Jedi Knight
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Dale, if the square hole you mentioned is the one right below the round screened outlet, then that is the way it came from the factory. It should have a angled reflector attached to the flat box section. Yes the idea was to direct some of the air flow down to your feet. See the attached photo. You can see the deflector. This opening is in addition to the hinged door that controls the heater air flow.
After using my bildge blower a few times, I am going to put the screen back in place on the outlet. Without it I think too much of the air flow goes straight back instead of down to my feet where it's needed. This photo was taken before I removed the screen.
After using my bildge blower a few times, I am going to put the screen back in place on the outlet. Without it I think too much of the air flow goes straight back instead of down to my feet where it's needed. This photo was taken before I removed the screen.
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RestoreThemAll
Jedi Warrior
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Douglas,
I'm not an machinist/mechanic/engineer but I do like to experiment. Sometimes its a fail.
It may not absolutely need the speed reduction but the new motor does push more air. I do not have the box installed in the car yet so I can't give a complete report. I also like that the variable speed switch starts the motor slowly. There's no sudden impact on the 54 year old box. These smith boxes can and do crack.
The shaft was 5/16" and needed to be 1/4". I put the stripped down motor gently in a vise on the bench and borrowed the car battery an control switch. I turned the shaft and using a file and emery cloth slowly took off metal. I was careful to check the measurement often with a caliper, and test fitted the cage for fit many times. Again, slowly and carefully. Take off too much or take it off uneven and you have a new challenge.
I'm not an machinist/mechanic/engineer but I do like to experiment. Sometimes its a fail.
It may not absolutely need the speed reduction but the new motor does push more air. I do not have the box installed in the car yet so I can't give a complete report. I also like that the variable speed switch starts the motor slowly. There's no sudden impact on the 54 year old box. These smith boxes can and do crack. The shaft was 5/16" and needed to be 1/4". I put the stripped down motor gently in a vise on the bench and borrowed the car battery an control switch. I turned the shaft and using a file and emery cloth slowly took off metal. I was careful to check the measurement often with a caliper, and test fitted the cage for fit many times. Again, slowly and carefully. Take off too much or take it off uneven and you have a new challenge.
RestoreThemAll
Jedi Warrior
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Rob, my car is missing the deflector but yes that's the hole. I'm going to leave it as is for now. No deflector might actually be helping a bit.
RestoreThemAll
Jedi Warrior
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Ray, my body panels are not yet installed and won't be for a few weeks so I have time to do something with the grill/radiator area. Though I'm not excited about adding too much sheet metal.
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Ray,
I think you're right - the blower is most accessible in the front position. Having removed the brackets, the blower looks cleaner and it's light enough to be suspended by the hose mountings.
My air control panels work pretty well, but IMO they're a difficult solution, requiring a lot of cutting and fitting by trial and error.
Per Chuck9482912 above, the rally "scoop" panels on either side of the grille, with holes for the heater and fresh air intakes, may be an easier way to get the same results. Not sure how well they keep engine heat from recirculating through the radiator, though.
I think you're right - the blower is most accessible in the front position. Having removed the brackets, the blower looks cleaner and it's light enough to be suspended by the hose mountings.
My air control panels work pretty well, but IMO they're a difficult solution, requiring a lot of cutting and fitting by trial and error.
Per Chuck9482912 above, the rally "scoop" panels on either side of the grille, with holes for the heater and fresh air intakes, may be an easier way to get the same results. Not sure how well they keep engine heat from recirculating through the radiator, though.
Last edited:
RAC68
Darth Vader
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Hi All,
I hope I have not confused the situation but we are talking 2 different ducts and channels.
Heater duct with squirrel cage blower is routed on the right-hand side of the engine into the duct that passes across the cabin with flip-down vents toward the floor. Since the purpose of this channel is to primarily carry heated air and also provide windshield defogging, it is less important if reheated radiator air is sucked into this channel of cabin air flow.
The cold air duct, supported with a bilge blower, is located on the left side of the engine compartment and delivers air to the cabin primarily through the round screened opening as well as through small louvered openings on the bottom of the square box. Since the round screened opening is quite large with little resistance, the primary flow of air passes through this port. Placing a deflector to direct air flow downward would be beneficial in directing ventilation toward the foot well with, or without, the added air flow supplied by the bilge blower. It is the cold air duct that is most negatively affected by the induction of re-heated radiator air at low or no speed.
Keep in mind that the square cabin duct passing across the fire wall has a separation between the heater side and cold air side and both could be used to provide ventilation to the cabin simultaneously (especially when the water valve turns off flow to the heater core).
Cold air input deflector:
Steve has created a few panels that will effectively seals of radiator recirculation. However, the application of these panels will be difficult to apply on a completed Healey.
Although my initial attempt (see entry #5 of this thread) to create a panel has improved the elimination of hot radiator air from being sucked into the cold air duct, I believe a more effective approach is still left to be discovered and plan to pursue during this season. I will definitely provide any solutions I find but suggest you look at Steve’s solution and the one I had presented until.
All the best,
Ray(64BJ8P1)
I hope I have not confused the situation but we are talking 2 different ducts and channels.
Heater duct with squirrel cage blower is routed on the right-hand side of the engine into the duct that passes across the cabin with flip-down vents toward the floor. Since the purpose of this channel is to primarily carry heated air and also provide windshield defogging, it is less important if reheated radiator air is sucked into this channel of cabin air flow.
The cold air duct, supported with a bilge blower, is located on the left side of the engine compartment and delivers air to the cabin primarily through the round screened opening as well as through small louvered openings on the bottom of the square box. Since the round screened opening is quite large with little resistance, the primary flow of air passes through this port. Placing a deflector to direct air flow downward would be beneficial in directing ventilation toward the foot well with, or without, the added air flow supplied by the bilge blower. It is the cold air duct that is most negatively affected by the induction of re-heated radiator air at low or no speed.
Keep in mind that the square cabin duct passing across the fire wall has a separation between the heater side and cold air side and both could be used to provide ventilation to the cabin simultaneously (especially when the water valve turns off flow to the heater core).
Cold air input deflector:
Steve has created a few panels that will effectively seals of radiator recirculation. However, the application of these panels will be difficult to apply on a completed Healey.
Although my initial attempt (see entry #5 of this thread) to create a panel has improved the elimination of hot radiator air from being sucked into the cold air duct, I believe a more effective approach is still left to be discovered and plan to pursue during this season. I will definitely provide any solutions I find but suggest you look at Steve’s solution and the one I had presented until.
All the best,
Ray(64BJ8P1)
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RestoreThemAll
Jedi Warrior
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That looks nice Steve. A little satin or flat black paint on that aluminum and clamps and it'll be barely visible.