How works a vw thermostat (long read, data heavy)

[herbie1200]

It should be in the path from opening to the fan.

In the 1st picture the sensor is just in the upper of the cyl.1 exhaust outlet, one of the hotter point of the engine.

If sealing of the bottom of the car is not perfect (impossible to be) hot air sucked by the fan passes near the cyl.1 exhaust becoming hot.

I made the same test, put the sensor on the fan shroud just in the top and (until now) never read more than 20°C.

Cannot give more precision because my gauge starts the graduated scale from 40°C but the "hand" of the instrument rests in the 20°C - 68°C position.

The same sensor, when near the thermostat, give the same readings of yours (rapid raise up to 60-65°C then, depending on various conditions, 80..120°C)

[pjpalm1964]

I may have missed it, but what sensors are you using, and how can I setup my car to get this data?

Part# please! Links to where to buy?

Keep up the interesting data logging.

[ekacpuc]

Cool thread. I always wondered how far the thermostat was actually open while driving. Never worried about it though, figured since mine works it was designed in a cold environment so I was good to go.

[volkaholic1]

to answer pjpalm1964 about how to get the sensor, i have not really thought about it, all the insturments came from Amazon, except the thermostat sensor, which i could make for someone that wanted it. it would be great to get some other data from other folks, other setups, other locations, etc

anyone can PM me if interested
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Volkaholic

[Max Welton]

I got my open and closed element temp sensors from diyautotune

https://www.diyautotune.com/shop/sensors-data-logging/temperature-and-pressure-sensors/

Max
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1967 Type-3 Fastback
Under the Knife https://shoptalkforums.com/viewtopic.php?f=24&t=151582
Home Stretch https://www.thesamba.com/vw/forum/viewtopic.php?t=767836

[bnam]

Just read the analysis and data - good stuff. One observation -- the rain guard possibly has an impact on the readings.

In my car, the rain guard caused increased temps vs. the stock vented decklid. Is it possible that the rainguard causes a low pressure area at the *outside* of the vents which reduces the overall pressure in the engine compartment. Which effectively means that some of the air in the compartment is being drawn out there rather then fed it. Taping it up stops that and improves the pressure in the engine compartment -- resulting in lower temp.
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1971 1302LS Convertible (RHD) owned since '74
Click to view image
1965 Karmann Ghia Coupe - under restoration
1966 Fiat 1500 Cabrio (with 1600 Twin cam)
1952 Citroen TA 11BL

[volkaholic1]

interesting, i have more tests planned, it has been a cool and wet spring, so not really good time yet for testing.
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Volkaholic

[dawie]

Volkaholic1 wrote: "i have more tests planned".

Thats good news.

Any chance of loosing that 009 and fitting an svda?

[volkaholic1]

SVDA not out of the question,,, are you expecting different engine temperatures? or what?
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Volkaholic

[dawie]

Without vacuum advance, timing could be around 10 degrees too late during lighter loads/light throttle conditions. Too late timing cause wasted energy/heat.

[grandpa red]

So I live in Ca.
When I bought mine it did not have the flap set up.After reading here the majority say the flap set up should be in these engines to make it heat up properly.So I bought a flap set from a vendor on the Samba.

Long story short I contacted an engine builder here in SoCal regarding a turnkey engine and asked if the flap kit was installed and he told me they do not install them because of the climate here.He made the remark "do you live in Alaska"!

So here in the San Francisco Bay Area is a flap kit really needed?
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'72 Beetle

[Max Welton]

[volkaholic1]

well the SVDA dis may be worth trying, thanks for the recommendation

as far as "do i need flaps" yes i agree, this is really a data collection thread, not a dissucssion on flaps per say, and as stated above, there has been lots of talk on that,,, but i will say this

will the engine run without flap? YES, certainly, but at what cost?
for example, will your engine run without air cleaners? YES, but at what cost?
will your engine run without all of the engine tin installed? YES, but at what cost?
you could strip it down to just the long block, and it would run,,, for awhile


I believe it was Mark Twain that said "the coldest winter i ever saw was the summer i spent in San Fransicso". but what do i know?
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Volkaholic

[herbie1200]

[udidwht]

[udidwht]

[volkaholic1]

i am just waiting for it to stop raining and warm up, my front yard is like 5" deep in water, right now when is summer going to get here? then i can get some more testing done,
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Volkaholic

[vamram]

[volkaholic1]

finally got warm enough to do some more testing, this one is a strange one, please do not be offended,,, this is UGLY! this is the baja scoop run on the backs of baja bugs, i got is duct taped on, i know i know, please forgive me, but i am not making holes in this very original car. what i want to test is the scoop at the top of the fiberglass, does it push more air down into the engine?

i had my doubt as to if this would have any impact, i have 3 runs to compare, all starting in the mid 80F outside, 1 - baseline, no modifications
2 - tennis ball trick
3 - baja scoop

engine compartment temps are all black lines, with different colored dots

stat temp are all red lines, with different colored dots

looking at the results, it shows that the scoop really does do something, while the tennis ball trick still has the best results as far as engine compartment temperature, the baja scoop has lower engine compartment and stat temps. we are seeing cooler temps in the 10-15 deg F range, i call that significant.

the next tests are more valid, as they will the things folks actually do, but i wanted to see what if anything would come from this

your thoughts?
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Volkaholic

[volkaholic1]

i added a venturi ring to the fan inlet, did before and after air flow testing, i decided it needed it's own subject line, check it out if interested,

https://www.thesamba.com/vw/forum/viewtopic.php?p=9113178#9113178

real world thermostat and engine temp data on the way!!!
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Volkaholic