Which Pressure cap??

[Smithy111]

Haven’t checked what mine has yet but ordered a new expansion tank and cap and there were two options - 15psi and 10psi. Apart from whatever is on there now how do I know what it should have? Cars an 84 te 

[CarBuff]

I've never heard of a 10 on an Esprit. All the ones I've seen on Turbos have been 15 PSI (or one Bar).

 

Make sure there are TWO rubber seals inside. Later ones I've seen from Lotus did not have the larger seal under the cap...

[Smithy111]

Would a 10psi cap mean it runs hotter then but under less pressure? Have checked and mine has a 15psi cap at present.

Also can anyone tell me the coolant capacity of a G esprit turbo??

[drdoom]

Chris,

Can't help with the coolant capacity question however the purpose of pressurizing a cooling system is to raise the point at which the coolant will boil. This is important due to the great reduction in cooling at internal engine hotspots where the steam will act as insulator, rather than conductor. One presumes there then follows a vicious cycle of hotter hotspots, creating more steam, and so on. As far as I understand it.

Cheers

[Smithy111]

Ok I’ll stick with the 15 psi cap and send this one back for a new 15 psi one. Thanks.

if anyone knows about the coolant boiling that would be great

[Guest gbowick]

The boiling point of the coolant with a 15psi cap would be c121C while with a 10psi one would be c115C