Testarossa radiator cap, 0.9 or 1.1 bar?

I called Motorad and got the information about the different caps
The caps in question are
Non vented
Stant 10230 or Motorad T16
Stant 10330 or Motorad ST16
Vented
Stant 10231 or Motorad T16V
Stant 10331 or Motorad ST16V

The “300s” have the red security lever (hence the S) and the “200s” are regular without the lever.

the “1s” are vented and the “0s” are non vented.
The Motorad number is easier to decipher. S for security and V for Vented.
The “vented” ones mean they have a dangling valve at the bottom (pictures of both Vented ones attached), this valve is for the coolant recovery system, as long as I know our cars don’t have a coolant recovery system, so MAYBE the ones without the dangling valve would be a “better-ish” replacement of the stock cap, and I wrote “ish” because it might not be any difference, only an extra valve that is not used at all or maybe the system is venting a bit until pressure is created and then shuts.
If the dangling valve is extra without creating any difference I think all 4 would work just fine, it is a matter of preference if you want the red security lever or not.


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And just to add to my previous post
The Stant caps (which are now very hard to find new as Motorad owns Stant since 2020 and most caps are now marketed as Motorad only) the cap number were the last 3 digits (230,231,330,331) and the first two digits were the type of package, 10 were boxes and 11 were in a flat cardboard. (10230 and 11230 pictures attached)
So if you still want to find the original Stant caps vs the Motorad, you can try with either 10 or 11, so to sum it all

all Caps are 16psi or 1.1Bar

Non vented
Stant 10230/11230 or Motorad T16

Non vented with Red Security Lever
Stant 10330/11330 or Motorad ST16

Vented
Stant 10231/11231 or Motorad T16V

Vented With Red Security Lever
Stant 10331/11331 or Motorad ST16V

My personal choice is Stant 10230/11230, it is a non vented cap (no coolant recovery system) just like the OEM and the design is similar to the OEM without the red lever and 4 ears (the equivalent Motorad T16 is 2 ears)
This for everyday driving, for concours I will put back the original 101499 0.9bar.
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https://www.ricambiamerica.com/expansion-tank-cap-radiator.html

correct material etc

 

Yes but not very reliables, I do have one for concours, for everyday driving I use a Stant 10230