Can you test sodium valves whilst in the the engine

what year is your car?

 

All 2 valve 308's came with sodium valves, Ferrari stopped using with the introduction of the QV.
Unless you have service records from previous owners, there is no way of telling if the valves were replaced.

 

I can't think of any way to test them in situ. My 2V 308 engine was 40 years old with about 50K miles on it when I pulled it and removed the heads. The valves, both intake and exhaust looked OK, guides were within spec, stem seals were OK but it was time to replace them. Most of the gaskets had deteriorated to some extent and there was a bit of corrosion on the mating surface of the intake manifolds. I did find two cracked valve shim buckets and replaced them all. Replaced the exhaust valves with stainless steel ones.

I cleaned up one of the sodium filled exhaust vales and inspected it under magnification. Couldn't find any cracks. We even magna-fluxed the valve and didn't find any cracks. Don't have an X-Ray machine laying around but maybe I can talk my dentist into zapping them. But I'm glad I replaced them. There are a lot of threads discussing this topic on this website. Search fur them and read through them. The opinions are as varied as those on the topic of timing belts.

In my opinion it boils down to the Clint Eastwood line: "Are you feeling lucky?"

 

It’s easy. Wind her up to 8k. If the valves let loose, open her up and look for sodium.

If they don’t let go, you know you are good to the sporting regs

 

And if one fails the test in situ?

You should either forget about them or just go ahead and rebuild the head because you already test them every time you drive the car.

 

I've asked Brian (rifledriver) whether the sodium valves are magnetic and I believe he said they were, but I'd hate to have you make assumptions based on my memory. The post is somewhere in the archives here though, and that may very well provide the answer to your question. I'd think you could attach a small magnet to a USB borescope camera and test the valves in situ.

 

Just to be clear. Testing the condition of sodium valves in situ is BEYOND IMPOSSIBLE. The ONLY way to have any chance of assessing the condition of the valve is to have the valve by itself, out of the engine, and then perform metallurgical testing on it. Just the cost of the testing would be more than the cost of buying a new valve so the practical answer is that you only have one of 2 options:

1. Leave the engine alone and stop worrying about it. Don't for a moment think that keeping the revs low will prolong the life of the valves. They can break while idling or even when cranking the engine over. The valves do not 'half-break' they fail totally and you need to decide what your threshold for potential damage is.

2. Remove the engine, pull the heads and have them re-built with new valves. I have been involved with 2 of these jobs in the last 3 years and can tell you that with the engine sitting out of the car, the decision to replace the valves and re-build the heads will cost you about $3K. This figure includes head gaskets, new valves, machine work and complete head assembly by a specialist, new seals, and some incidental expenses that always crop up. The figure does not include removal and replacement of the engine or any other 'while you are at it' costs.

If you are not sure whether the valves are sodium or not I can say that with the cam covers off you can stick a magnet to the tip of the valve to see if there is an attraction. Stainless steel valves will not attract but a sodium valve will although the actual attraction is fairly weak (I tested this a LOT) so it can be deceiving. Just be sure that ALL 308 2 valve motors had sodium valves from factory so any test is to determine if they were changed at some point in the life of the engine.

 

Yeah, that'll work.