Is this the OEM Tstat?

[Bigggy]

So I finally decided to pull out old Tstat and install my Reisch 170. Is anybody able to tell me if the one on the right in the Google Drive link below is the OEM? It is marked "54mm", "USA" on top and "X", "STC" on the bottom. The new one is marked "56mm", "USA" on top and only "STC" on bottom. The old seems to be a little loose in the housing compared to the new one fit perfect, maybe that explains the 54 VS 56mm?

https://drive.google.com/open?id=0ByPslytANOi9cXFva0F2M0stVGs

Thanks in advance!

 

[jrgoffin]

The "STC" stamp is for "Stant Thermostat Corporation" - they also supply the OE thermostat.

 

[P49Y-CY]

yes that pic looks exactly like the stock t-stat from my 2003. i have two of them, and both say 54 mm but interestingly enough, my 2004 also says "motorcraft", "180*F", and "2C5E-8575-AA" (no "X").

i too noticed that the 56mm fits in the housing better

 

[jrgoffin]

The OE thermostat housing has an ID of about 54.1mm...

 

[Bigggy]

Housing is 54.47mm, OE Tsat is 53.91mm and new Tstat is 54.24mm. Installed perfectly in the housing.

 

[jrgoffin]

Amazing what you can do to the flange of a thermostat with a lathe...

 

[Bigggy]

Amazing what you can do to the flange of a thermostat with a lathe...

I'm not sure I'm following... I didn't do anything to the flange nor the housing, everything is as it was and I measured everything with a caliper.

 

[jrgoffin]

The original flange OD was 56mm, and it's now roughly 54mm. Had to get that way somehow.

 

[Bigggy]

Well maybe it's stamped that but that does not mean it's really that size. The Stat came from Reische as is, but yeah can't explain why it's stamped 56.

 

[jrgoffin]

It's stamped 56mm because that is the original size. The housing then gets turned in a lathe so it will fit the 54mm opening in the OE housing. Pretty simple.

 

[Bigggy]

Maybe that's the case! Anyway it is suppose to fit the Ford 4D application. I've put some coolant in the car, still need to start the engine and burp the system.

 

[jrgoffin]

Maybe that's the case!

There's no 'maybe' about it. That's how it's made to fit.

http://www.terminator-cobra.com/cooling.htm#170°_Thermostat