Thermostat comparison

The Wahler web site states that Wahler is an OEM supplier for Fiat, VW, Ford and GM.

 

i've been running this stat for about two years now with no problems. replaced it when i replace my radiator.

 

Are there 2 different Wahler 056121113A parts? Here is a link to that part number, but it is clearly a different part than the one at Superformance.

http://www.veedubwarehouse.com/details.jsp?partnumber=056121113A

Aaron

 

Yes I see that picture is not at all like the one I purchased locally. I guess that's another reason to buy local you can inspect the part before purchase to make sure it is what you want.

I would like to see a picture of the $60 Behr thermostat that Dennis McCann sells and I would love to know the part number. I heard from someone who purchased one that it did not come in manufacturers packaging.

 

I got one of those from Dennis and sent it back. It did not have the plastic disc at the bottom, and the opening was way too small, IMHO. (Otherwise, my experience with Dennis has been great)

 

I agree with you that the small opening would be unacceptable. I assume the thermostat you recieved from Dennis McCann had a disc and that your objection was that the disc was made of metal instead of plastic. Is there a reason why the plastic disc would be preferable? This is an interesting point because if you go back 20 posts and look at post #10 in this very thread you will see another member who specifically objects to the plastic disc. In addition he stated the the replacement part which was supplied by an authorized Ferrari dealer (FoW) did not have a plastic disc.

 

I guess that my preference for the plastic disc, is because that's how it was originally designed. Maybe it's just superstition or some other irrationality. With something as important as a thermostat, I just get nervous about how it seals and the opening size.

 

Hi guys.

In answer to Geometry and all the fchatters from this post, I've bought the Superformance Tstat, and 0 problems by now.
My Tstat is Motorad, made in Germany. I attach 2 pics. Inside the back hole -oooppssss!- is marked the opening temp. See the pics.
I suppose that Superformance is selling many different Tstat makes.

Cheers
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I think that is a MotoRad part number 234-180. I can't find a supplier for that item. The pictures you provided did not give a good view of the opening but based upon the picture on the manufactures web site I would say that the opening is on par with the opening in the Stant thermostat in other words a bit smaller than the opening on the OEM part.

 

I send another shot of the thermostat.
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Thanks for the reference. I just ordered one to check out.

 

I am interested to hear your opinion.

 

Well, they are ALL wax motor thermostats.

If you can find one that fits, a simple Robert Shaw balanced flow $14 T-stat will work just as well, and is made just the same as any $200 T-stat.

The Robert Shaw unit will fail open, if it does fail.

Now,as far as a Ferrari T-stat being better, well, Ferrari contracted out some T-stat maker who makes T-stats for Yugos and Ford Pintos and Chevy Malibus and Volkswagons to make T-stats for them, but at probably slightly different dimensions to make it Ferrari.

The R-S T-stat is also sold under the Mr Gasket name.

Doug

 

BTW, Water passage (valve) diameter is only half the story.

The other half is valve stroke

A T-stat with a valve diameter of 22 MM will flow the same amount of water as a 44 MM diameter valve if the 22 MM valve is open twice as far. Simple math, surface area of a cylinder. Pi X D X H.

Longer stroke, in theory, gives you more precise water flow control, but at the expense of greater movement of the wax motor and wear on the motor piston seal.

Doug

 

Doug,

I'm having difficulty seeing how your math would apply here. The volume of fluid flow is not that much different the current flow through a wire. In essence, the larger the wire diameter, the more current that can flow through the wire. As the openning in the thermostat is the "limiting factor" in determining the flow (volume), the distance the thermostatic plate opens really doesn't come into play, unless it "blocks" the hole.

Imagine that you have two vertical columns of water, each with the same volume of water in each. One column is two inches in diameter, the other is one inch in diameter. If one were to remove "a stopper" from the end pointing down, and measure the volume of water that came from each column, over the same time interval, the larger diameter column would flow (deliver) more volume...Wouldn't you agree?

David

 

A T-Stat is an orifice plate flow meter.

Since the area of the T stat is much less than the area of the pipe it is restricting, the amount of opening length will vary the area of the orifice, and thus flow rate.

Flow is also a function of pressure, higher pressure = higher flow through an orifice.

You never want too large of a T stat opening (or no T stat at all), as an important function of the T stat is to act as a restrictor so that there is positive pressure inside the block. Higher pressure coolant has a higher boiling pressure; for example pressurizing the water jacket by 10 PSIG via a restrictor T stat raises the boiling point of pure water from 212 degrees F to 240 degrees F, at 20 PSIG in the block, the boiling point is almost 260 degrees F. Water that is not flash boiling on hot surfaces conducts heat much better without an insulation layer of steam.

I have some water pump flow curves around here for a Chev V8, and those water pumps will generate up to about 60 PSIG, of course higher back pressure on a centrifugal pump means reduced flow, at some point the pump will not flow at all, so a T stat acts as a flow balancer.


Doug

 

Please allow me to interject my 2 cents worth. There is a huge difference between Genuine and aftermarket parts. As some of you might know we own several Subaru Service Centers and use genuine Subaru parts. We have found over many years of servicing Subarus that aftermarket parts are not the quality of Genuine. Thermostats are a particular interest to us. Many of our turbo customers go aftermarket with all sorts of add ons including aftermarket t/stats. We actually purchased 10 different aftermarket stats and installed them one at a time in the same turbo WRX, under controled conditions. We had the vehicle at idle for 30 minutes with each stat hood closed, in the sun. Then we road tested the car on the freeway at 60 miles per hour for 30 minutes. At the end of each time limit we used a digital thermo imager at pre determined locations on both the motor and radiator to read temps. We started with the genuine Subaru stat and then worked our way down from the most expensive aftermarket to the least expensive one.

While price point did not seem to matter, the difference in temp numbers did. Using the O/E t stat as a norm we charted the the different aftermarket units. The idle temps varied (+ ) 15 degrees. We also noted the difference of temps after our 30 min drive and those numbers varied some 18 degrees(+). We found the aftermarket stats had slower opening rates and often times did not fully open and restricted coolant flow meaning higher engine and radiator temps. Also some of the aftermarket stats did not have the release valve or hole in the flange. Also on the genuine Subaru stat the bellows and valve are off set from center, the aftermarket units had the bellows and valve centered. Subaru has a specific placement for the off set. This WRX had a mechanical temp gauge that we were able to chart the rising temp readings during the tests. All but one aftermarket stat had higher temp readings than the genuine Subaru unit.

A car manufacture spends millions of dollars designing and building their products. Why would a vehicle owner buy a cheaper non tested part to install on their car? The reason they are cheaper is that they are made of less costly materials and usually designed to fit a number of different vehicles thus spreading their design costs over a broader market base.

I for one would not trust a Pep boys T/stat or any other aftermarket replacement stat in any of my cars let alone my 308 that I just spent nearly $15,000 grand remanufacturing the motor, but again I don't buy lottery tickets either. Why take a chance by saving a few dollars with an untried unproven cheap aftermarket part? There's my 2 bits worth on aftermarket parts, don't buy 'em don't use 'em, well maybe on your Pinto not on your Ferrari!!!!!!!

Howard Musolf
1981 Ferrari 308gtsi
Maserati spyder

 

Because the "proper" OEM thermostat is no longer made. Savara is out of business. Any of the "new" Savaras you can buy from fpart dealers are 20 years old. They might be unused, but they aren't new. Oh, and they are $250. Now if you want to pay $250 for a 20 year old thermostat, you go right ahead. I would rather buy a newer, possibly better one. Thermostats are not magical. They are pretty simple, basic devices. A quality thermostat of the right specs is going to be fine.

I ordered the Wahler mentioned above and it is by far the closest to OEM specs that I have found so far, and appears to be the one that Superformance UK is selling on their site as the replacement for the 308.

I bought it here:

http://www.autopartsway.com/AutoParts2/index.cfm?fetch=altPart~ID=W0133-1633589&partnumber=W0133-1633589&a_aid=176b5dca&data1=frugalmechanic

It arrived in 2 days. I put it in boiling water and then test fitted it hot to the thermostat housing to be sure it opened enough to close off the secondary orifice in the thermo housing when the car is hot. It does. I also noted that it opens at the right temp, which my old Savara doesn't. (The Savara opens well before 190 degrees, which is why my car could never warm up except in very hot weather).

Comparing the Wahler to the Stat that I picked up for comparison, the center opening is much larger (the same as the Savara). I think we have a winner, but I'll report back once I have it in the car.

GeoMetry, thank you for your research on this, you nailed it.


Birdman

 

For posterity...
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So the 308 T-stat 109671 can be replaced by Wahler 056 121 113F
What about the 328, the F-part number is 128991
Is it the same?? I believe not
Superformance is not selling one for the 328

 

That is a good question. It is my understanding from reading the threads here that there is some difference between the 328 and the 308 thermostat, although in casual appearance they look pretty much the same. I have actually been on a mission to find a good 308 thermostat for a while, and in fact have had several dialogs with Behr (documented in the Tech QA section) over several months. I have purchased now several thermostats which were not the right one. What I found is that just about every Fparts dealer is selling an aftermarket version as an alternative to the Savara (GT Car Parts sells one, Dennis McCann sells one, Superformance sells one) and none of them are the same thermostat. It appears that these guys all went out independently and found something that is about right, just as we did! But then they end up selling a $15 thermostat for $50. And as some people discovered, some of these "correct" replacements for the 308 thermostat only have a 28 mm ID which is 3 mm smaller than the original. That bothers me because we know these cars need to have enough flow when they are hot.

Unfortunately, I think that if you want to find a good alternative to the 328 thermostat, you need to take it out of the car this winter and start investigating! Take it to some parts places and start matching it up.

BTW, it is my understanding that Wahler is made by Behr, and Behr is the manufacturer of the more recent Ferrari thermostats. They are made by the Italian Division of Behr. Behr never made OEM thermostats for 308s or cars of that era, but because they are the OEM manufacturer for newer Ferrari thermostats that come in a yellow box, they are the closest thing we will get to an authentic Ferrari thermostat. I have a part number from Behr Italia that is supposed to be the Behr cross-reference for the Savara but I haven't ordered one yet. I probably will, just for fun. I expect it will end up being the same as the Wahler in my possession already.

Birdman

 

I just heard back from the guy at Hella (US Importer for Behr) and he says this is the right cross for a 308:

http://cat.hella.com/hella232/jsp/search/advanced/Frameset_ButtonBar_Bottom.jsp?nologin=yes&currentObjectId=CA@USAData@[email protected]

Birdman

 

OK
I will take it out and investigate this winter
Mondial 3200 1987 by the way

I have an overview of Behr T-stat references
Looks like the 1.150 (ID 30mm) or 1.148 (ID 33mm) is a closer match than the 1.173 (ID 35mm) (all have OD 54mm)
The file is 3,3MB so cannot upload, got it from the german Behr site but has been removed
I am not sure Wahler belongs to Behr, seems to be independent as per there german site
Behr is part of Hella now
I have emailed it to your oceanic address

 

Thanks, got it. I think the you are right about Wahler. Doesn't look like they are part of Behr. I think 1.105 is the closest one, because it it's a tad longer. The OEM Savara measures about 33mm long. Of course, I can't find 1.105 in the USA Hella catalog, so I'm not sure it's available.

 

1.148 is too short (28 mm)
1.150 is WAY too short at 25.5 mm

1.173 is pretty close
1.105 looks like the best, length is 33mm