Which radiator cap please?

[Russell Hall]

Head corrosion was probably from using hard water although Bruce Tayler had a theory about the electric current from the fan clutch. Towns that use bore water were deadly. The thing that used to clog were the heaters.

 

[2pac]

One of the most common conversions I perform to 504's in my workshop is to fit later 505 cross-flow radiators. This not only dramatically improves cooling efficiency but also allows the running of a 13psi Cap. The addition of an expansion bottle also reduces the need to frequentlyTop-up the cooling system.

Paris

what do you refer to as later models?

 

[Beano]

As far as I know, the early 504s had welsh plugs which were only suited to a 4 lb cap. Not sure when they changed...perhaps when the square port head came in ?

 

[Wildebeest2]

504 Freak reply re the fitting of a cross flow radiator allowing the fitting of a 13 pound cap. Why? The engine itself will be affected by the higher pressure. Welch plugs. Water pump seal. Hoses. Heater core. Head gasket. I was told because the 404 and 504 cooling systems are only circulatory there is no need of a cap higher than 4 lbs/sq". In the past I had noted Bruce Taylors theory on residual current the cause of corrosion. I fitted a cable from the thermostat housing to the body to my 504 as advised.

 

[2pac]

One of the most common conversions I perform to 504's in my workshop is to fit later 505 cross-flow radiators. This not only dramatically improves cooling efficiency but also allows the running of a 13psi Cap. The addition of an expansion bottle also reduces the need to frequentlyTop-up the cooling system.

Paris

why does the larger radiator allow a higher pressure in the system?