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89 420sel, 83 volvo 244
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Discussion Starter #1
if anyone has their heater blower motor out, would you be kind enough to measure the hole under the motor assembly? i am going to make an adaptor plate and install a pair of dayton axial fans, hoping for more air flow and quieter operation. also if anyone knows the cfm of the original squirrel cage, it would help me to make the fan choice, thanks.
 

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if anyone has their heater blower motor out, would you be kind enough to measure the hole under the motor assembly? i am going to make an adaptor plate and install a pair of dayton axial fans, hoping for more air flow and quieter operation. also if anyone knows the cfm of the original squirrel cage, it would help me to make the fan choice, thanks.
I will be doing this in the next week on the 380, to deal with some surface rust issues and to replace the gasket between the motor housing an cowl, which is shot. Remind me.
 

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The base of the whole fan is roughly 320x130mm and the 2 holes in the metal work under it that it pushes air into are about 120x120mm.

As to the CFM many people have asked in other threads i have read and i have never seen a answer even after searching for aftermarket ideas on how to replace the fan with something better and quieter.
I would be more inclined to go on the wattage of the fan as that will give you a much better idea of the amount of air it can move seeing as its got to push it thru 2 radiators(hot and aircon) and along some bendy piping. Like a typical computer fans CFM drops drastically as soon as it has to push thru anything major. Its on a 16amp fuse so its probably pretty safe to assume its running about 120W-160W max.

Can you please link the fans you plan to use cause i would be very very interested in how this works out for you.
 

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89 420sel, 83 volvo 244
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Discussion Starter #4
thanks

the fans i am thinking of using are Dayton axials 2RTJ6. they are ball bearing 3800rpm, 170cfm and 12vdc. they can be found in Grainger catalog, online or paper. the direct push of a fan blade should be more effective than the original hamster wheel, i hope.
 

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sorry to burst your bubble but that wont quite work. Thats a standard computer fan and it draws a total of 14Watts i had a look at them and there is no way they will cope, you put 2 of them in to do the job of the current fan and all you will feel is if your lucky a slight breeze.

Best solution i have come up with is what most modern cars have, a big radial fan blowing air into a pipe which feeds into the dash area where needed. best thing about this is you can set up the in take pipe to pull the air from either outside or inside the car. But is not really a practical solution. In the area a cage fan is still probably best.
 

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85 380sl, 06 Jetta TDI, Wagon
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Have you tried to pull it out and give it a good cleaning and lubrication? When I got my 380 last year the fan was very loud and I thought a bearing may have gone in it. I figured if I needed to get a new one nothing would be lost from pulling it and trying to fix it myself. Well after scubbing over 20 years of grime off of it and giving it a good dose of lubrication on all moving parts and friction points, it now runs almost silently, and pushes a lot more air. Give it a try, what have you got to lose?
 

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yeah i did that, but not much luck. its works well but to me more of the problem is that it only takes outside air into the car so on a how day the aircon pretty much fails as it still blows warm air into the car after pulling in really hot air.

Thats why i am more considering some sort of inline blower that i can duct a intake from either outside or inside the car same as modern cars, plus i can put it where my battery currently is and move that into the boot.

But to keep it stock your best bet is to fix up your current fan, take it to a shop once u have pulled it from your car. Or find a source of new dual cage fans and buy one that you think will fit.
 

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bluefang said:
...the problem is that it only takes outside air into the car so on a how day the aircon pretty much fails as it still blows warm air into the car after pulling in really hot air.
Then you have a dampener/vent door issue, not a blower motor problem. In AC mode the cabin air recirculates, if the vacuum diaphragms and controls are functioning properly.
 

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89 420sel, 83 volvo 244
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Discussion Starter #9
here's the problem with my stock fan; i pulled it because it was noisy, especially in turns and discovered the pedestal part of the case which holds the motor steady was broken. the motor was dirty, but ran well after cleaning and lube. i reassembled using double stick tape and nylon cable ties to secure the motor and it actually works as well as new. however, i think the design and efficiency of the original fan and box is very poor and am trying to find a way to improve it. i have searched for an inline fan but cannot find one. i am also considering using 2 single squirrel cage blowers, running one for low speed and both for high. i don't consider spending $420 for an inefficient replacement to be a satisfactory solution.
 

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Then you have a dampener/vent door issue, not a blower motor problem. In AC mode the cabin air recirculates, if the vacuum diaphragms and controls are functioning properly.
Well theres my problem, never looked for that. Didnt realise that it had that function it only looks like the blower can draw in outside air.

yeah $420 for a fan is crazy i certainly agree with you there. Good luck finding something to replace the fan with. Just try and match the power draw of the fans not so much the CFM of air.
 

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89 420sel, 83 volvo 244
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Discussion Starter #11
i ordered a pair of bilge blower motors today from a marine supply house. they are right angle caged blowers with open intakes. sixty dollars for the pair. my plan is to make a cover plate for the opening under the original fan and secure it with the factory studs and mount the blowers on it, run one for low speed, two for high. hope it works as we are quickly heading into 100+ degree days.
 

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89 420sel, 83 volvo 244
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Discussion Starter #13
are you interested in a pair of bilge blower motors? only used for 5 minutes. (not enough airflow, serious noise)
 
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