How servicable are the sodium Exhaust valves in the P300 series ,are they capable of a long life or would it be a case of replacing with a solid valve type ?

The sodium filled valves are a weak point, best to replace with solid valves.

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Espada S2 7782
Jalpa ELA12175

Best to replace, but I have never had an issue either.

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Actively looking for a Countach, PM me if you are selling one!

Sold #FLA12191 in 2002
Currently
Jalpa #FLA12242 In NH as a parts car (waiting on another Jalpa sale for an engine and trans in order to be rebuilt debating an LS1 and MR2 trans axle transplant)
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It is essential to replace the sodium valves with solid ones.

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P300V8
Silhouette #40006 first production car, Urraco P300 #20200 sold in September 2009.

Keep in mind that the original Livia sodium passivated exhaust valves are light (weight wise)...most of the commonly available replacements are too heavy and negatively influence valve/cam dynamics.

You will also have to replace all valve guides with a more modern material since these wear out in less than 20K miles. Additionally pressure test the heads for leaks.

If you are doing the heads you may as well do the whole motor since the piston/cylinder wall clearances (.006+ inches) as Lambo supplies them guarantee blow-by and poor running qualities.

Paul

Has anyone ever done or heard of someone doing titanium valves?

A mechanic recommended this long ago and I thought it was interesting, but I have not heard it mentioned since.

Titanium valve $ 100. each
Retainer/Lock $ 35. per valve minimum
New valve seat Cu/Ni $ 30. per valve
Cut and install $ 30. per seat

So you are looking at likely a minimum $ 1600. for just the exhaust valves

Most "exotic car" places do not even know what Ti is...so you need to find a race car engine builder.

We used NISMO (Nissan racing) valves, which are super light austenitic S/S but they are no longer available...they did not require a new seat

Paul