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Woreign Samba Member
Joined: June 04, 2006 Posts: 2841 Location: Crestview FL
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Posted: Thu Jan 18, 2007 12:12 pm Post subject: How much spring tension on cooling flaps? |
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I recently installed cooling flaps in my Thing's engine. The spring tension seemed really strong, so I installed a link to lessen the tension. It still seems like it requires a lot of force to close the flaps. In fact, the thermostat no longer shrinks to activate the flaps. So either my thermostat is bad or it's not strong enough to pull the flaps. How strong are the thermostats? |
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bucko Samba Member
Joined: December 09, 2004 Posts: 2617 Location: Coppell, Texas
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Posted: Thu Jan 18, 2007 1:20 pm Post subject: |
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If I recall when I installed this setup in my sons 73 Beetle, the spring was not strong at all. It was just enough to pull the flappers open, and just a slight tug with my fingers would allow the flappers to close.
You sure you have the right spring? _________________ Current VW drives: 1984 Westfalia
Past VW drives: 1967 Beetle, 1973 Beetle, 1977 Bus, 1971 Military Type 181 |
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Woreign Samba Member
Joined: June 04, 2006 Posts: 2841 Location: Crestview FL
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Posted: Thu Jan 18, 2007 7:07 pm Post subject: |
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I think the problem is the thermostat... After spending some time in the freezer, it only shrank to 40mm, which barely fits into the bracket. When submerged in hot water, I noticed a stream of tiny bubbles escaping around the shaft.
Yup, it's toast... |
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bucko Samba Member
Joined: December 09, 2004 Posts: 2617 Location: Coppell, Texas
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ztnoo Samba Member
Joined: March 23, 2005 Posts: 801 Location: Indiana
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Captain Spalding Samba Member
Joined: February 19, 2005 Posts: 2519 Location: . . . in denial.
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Posted: Sun Jan 21, 2007 4:25 pm Post subject: |
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ztnoo wrote: |
Here are some additional resources for thermostats.
NOS is becoming very scarce.
They are no longer being manufactured. |
Just out of curiosity, are there any alternatives to the stock thermostats? I suppose as a last resort, a cable actuator could be used, but that would require that you manually close the flaps when starting a cold engine, and that you remember to open them when the engine is warm - not optimal or idiot-proof, I know. . . |
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Woreign Samba Member
Joined: June 04, 2006 Posts: 2841 Location: Crestview FL
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Posted: Sun Jan 21, 2007 6:10 pm Post subject: |
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Also, does anyone know what fluid is inside an original thermostat. I have one that has a small hole in the solder around the shaft. Maybe it's possible to refill the thermostat and seal the hole? |
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bucko Samba Member
Joined: December 09, 2004 Posts: 2617 Location: Coppell, Texas
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Posted: Sun Jan 21, 2007 6:27 pm Post subject: |
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I believe it was a gas substance.
Go to the "Late Model Beetle/Super" forum, whose moderator is Marc. He is "everything VW". This topic of thermostats was discussed in great detail (a couple of years ago that I can remember when I was restoring a 73 Beetle). Marc knew the answer.
By the way, found this on that site that shows the flaps and spring setup:
_________________ Current VW drives: 1984 Westfalia
Past VW drives: 1967 Beetle, 1973 Beetle, 1977 Bus, 1971 Military Type 181 |
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Woreign Samba Member
Joined: June 04, 2006 Posts: 2841 Location: Crestview FL
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Posted: Fri Jan 26, 2007 6:48 am Post subject: |
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I replaced the faulty thermostat with a good one, and now the engine runs great in cold weather! What a difference the cooling flaps make! No more stalling and hesitation! I am now definitely a firm believer in the cooling flaps and other German air cooled engineering! |
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Towel Rail Horizontally Opposed
Joined: April 15, 2005 Posts: 4622 Location: SE CR IA US NA PE
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Posted: Fri Jan 26, 2007 5:09 pm Post subject: |
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Captain Spalding wrote: |
ztnoo wrote: |
Here are some additional resources for thermostats.
NOS is becoming very scarce.
They are no longer being manufactured. |
Just out of curiosity, are there any alternatives to the stock thermostats? I suppose as a last resort, a cable actuator could be used, but that would require that you manually close the flaps when starting a cold engine, and that you remember to open them when the engine is warm - not optimal or idiot-proof, I know. . . |
Putting on my paranoid-survivalist cap, perhaps one could wire up an idiot light to the dash (in a non-scary color, like blue) and a temp sensor to the thermostat mounting bracket to tell the driver when the engine is at temp (65-70 C, if I'm not mistaken). Perhaps then the light could go out when the driver has pulled the knob to open the flaps?
Not perfect, but it could work. I'm definitely a believer in thermostats, so I've got a couple spares tucked away.
- Scott _________________ 1974 Thing -- under the knife
1967 Beetle -- spring/summer/fall driver
1996 Subaru OBW (EJ22, 5-speed, AWD) -- winter car, 3-seasons "don't feel like biking today" car
049 > 070 > 053 > 009 |
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Captain Spalding Samba Member
Joined: February 19, 2005 Posts: 2519 Location: . . . in denial.
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Posted: Fri Jan 26, 2007 5:44 pm Post subject: |
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Towel Rail wrote: |
. . . perhaps one could wire up an idiot light to the dash (in a non-scary color, like blue) and a temp sensor to the thermostat mounting bracket to tell the driver when the engine is at temp (65-70 C, if I'm not mistaken). |
The greatest risk with manual control of the flaps is overheating when one forgets to open them. Maybe a two-color L.E.D., with a circuit that makes it glow one color when the engine is cold, indicating that the flaps should be closed, and another color when the engine warms up, indicating that they should be opened. If the warm engine light remains lit for more than a minute or so, a piezo buzzer could go off.
Or better yet, rather than a cable actuator for the flaps, a solenoid controlled by a latching relay, which is in turn actuated by a thermocouple. That makes the system automatic. I'll have to research a bit to give the system the same flap-open-failsafe that the stock system has.
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. . . I'm definitely a believer in thermostats, so I've got a couple spares tucked away. |
Probably the best idea. I think I'll order a couple right now. |
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