Sodium filled valves

Thanks Al, that's very helpful info. I'll put it to use when I get the valves removed from the head, and report back. Cheers

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On another note, what is the process for installing new valves? I realize now I've always sent heads off to be refurbished and they generally cut a 3 or 5 angle valve job while there. I'll have my heads off on mine the next few months. Do the valves seats and valves need machining to fit or can they be lapped at home?

 

Doing it the old fashioned way is not as accurate as what the machinist can achieve with professional tools. Also my machinist adjusts the seats so as to start with all roughly the same valve shims, which makes my life easier on the next valve job.

As long as you replace some guides and want the head to be pressure tested, the additional cost on the seats is marginal (total 600€ per head, plus price of the valves).

If you just replace a single valve, maybe you could try the DIY approach. Not sure I would do it as far as I am concerned: although I have disassembled one of my head, I would not perform the assembly on my own, as I do not have the proper tools, and these pair of springs are hard.

 

My engine head are now a nice patchwork of valves. I've taken some pics for the record :

Stock Ferrari inlet valve on the left, Eurospares equivalent on the right.

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Sorry, I do not have stock exhaust valves on the head (no more sodium for me). Superformance on the left, Eurospares on the right :

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Side notes :

1. No Ferrari OEM numbers on my Eurospares / SF Valves
   
   
2. The Eurospares exhaust valves are slightly more thick, they protrude a bit more in the cylinder dome. These are actually the one that were hit by the pistons (see the small scratch on valve n°7). It's not the fault of the valves (refer to my embarrassing timing mismatch) but this gives an idea of difference in terms of thickness: Eurospares valve were hit, SF weren't. No idea on the potential effect (compression, weight, etc...), of this small difference.
   
   
3. The stock Ferrari inlet valves are still excellent after 100.000km!
   
   
4. my machinist is not as meticulous as my mechanic when it comes to valve numbering

Last but not least, next to my engine the mechanics are working on an old Colombo (from a 330). Our engine does look quite refined compared to its famous ancestor.

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Found my infamous original exhaust valve. As can be seen, the wall is quite thin which explain why these valves do break when old. Also the markings are on the tip, whereas Superformance are marked on the seats. Eurospares do have no markings at all.

One can check under the valve stem seals if the valves do have original markings on the tips. This implies to remove the camshafts, but does not require to drop the heads, so it's the kind of preventive analysis that can be performed at reasonable cost when adjusting camshaft timing.

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Hi all,

I'm currently replacing my exhaust valves with stainless ones and have fitted new valve guides.

Does anyone know the specification for valve seat concentricity for these engines?
I have found many specifications for other engines (some of which are astounding to say the least) and it would seem that concentricity values below .002" or .05mm should be acceptable according to a few online sources like the one in the following link.

https://www.enginebuildermag.com/2013/10/cautioning-on-valve-seat-concentricity/

It would seem from my online searches on this topic that a lot of shops have cut valve seats that are way outside this value and I'm wondering if this may have had an influence on why some members have previously noted increased failure of the sodium filled valves after head work had been performed as per this quote from the above link - “Non-concentric valves affect proper heat transfer from the valve to the valve seat and put undo stress on the valve head itself,” added Bauer. “Over time, the valve will fatigue as it tries to conform to the seat. Eventually, the valve stem will break, dropping the valve into the cylinder.”

It seems valves will seal and perform well under port vacuum testing even though they are a fair way above the .002" concentricity values so I'm aiming to get mine all under this value but it would be nice to have a proper spec to work to if anyone has one.

Cheers Al
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Not sure that in my case this was a concentricity issue: both the valve guides, and valve seats had been replaced, and the seat had been trimmed "in situ". The machinist is by no mean a DIYER and has performed much more complex "cuts" for me (reducing piston squirts, balancing crankshaft), by contrast a valve seat is a peace of cake so to say.

What I have however experienced is that when you place old valves on new guides, the motion of the valve is not homogeneously fluid: the last bit of travel before closing is not as smooth. I suspect that when we regrind the seat, we somehow allow the valve to get slightly deeper in the valve seat, which puts a portion of the stem in contact with the guide (which had not been the case for the 40 previous years). This new friction point is even worse when using new guides that have tighter tolerances than the older ones. Takes this theory for what it's worth...

What's clear however is that when working on the head, the old sodium valve should go...

 

Thanks for the reply Raemin.

Do you know what valve seat concentricity values your machinist worked to?

 

Don't know and I am not sure I can candidly ask him right now: I really appreciate his work for the most part, but the leaky cylinder head is a costly embarrassment...

 

In reading this with interest, I don't see a sure way to identify a sodium filled valve (unless I am mistaken). I have the head off an old 365 GT4 2+2 at the moment. I will naturally get the heads serviced (including replacing the exhaust valves if necessary) but don't know if the exhaust valves are original (therefore sodium) or have been replaced. The inlet valves look fine and are magnetic (head, stem and tip) with no markings on them. The exhaust valves also look fine (can be deceiving I know) and are weakly magnetic on the head and not magnetic on the stem or tip (unlike a previous post which talked about the tip being relatively strongly magnetic). The exhaust valves are also marked just above the collet O KE FS ST (the O in front is a symbol or logo with 2 wavy lines through it).

A few questions for the collective wisdom of this excellent group please:

1. Has anyone seen these exhaust valves before and know if they are sodium or not?

2. Does anyone know what KE FS ST means?

3. Has anyone cut open a valve to confirm if they are sodium or not? What are the risks in doing this? Not sure if sodium reacts badly to an angle grinder (I am happy to sacrifice 1 valve to know if the other 11 are good or not).

Thanks for all the useful info so far.

 

A complete overhaull of a working engine is roughly 100hrs of work and $2.000 worth of parts.
A complete overhaull of a broken engine is 200hrs minimum and $15.000 worth of parts/machining.

Wisdom : if you do not have the service record of the valve-train 12 x £48.74 is a false economy. For the sake of originality you can re-install sodium valves as long as they are new (€200 each).

 

Where do you get your parts from Raemin?

The $2000 worth of parts won't even buy me a set of the five timing chain guides then you have the timing chain on top.
The valve guides are 384 pound from Superformance (and 80% of the ones I purchased needed to be machined to the correct outer diameter before install).
Another $800 AUD for the head gaskets.
and then throw in a heap of new gaskets, O'rings belts and hoses at the bare minimum.

 

Hey Al, Raemin is probably talking in USD or Euros, which goes a little bit further than the Aussie peso. I got a full engine gasket kit from Sangalli, posted here for $850 aud. Includes all gaskets, seals, o-rings, and head gaskets, (not elring). I bought my exhaust vales via GT Car parts, better quality than the superformance ones I'm told, I think they were about $70 Usd. The head shop here does guides for around $25 Au. Head service with new valves fitted was $1500 at Ram Heads in Windsor. I can't remember what I paid for belts. Still yet to buy hoses, and pistons and bore and hone and the list goes on.....

 

That's only for what's in the owner manual's maintenance, i.e valve, valve guides, shims and gaskets. Replacing hoses, the chain and the tensioner is not mentioned but recommended.

2000€ should be more or less in the ballpark, and this is what my brother paid on his 365, but as said this is for the maintenance of a working engine...

If you add to the list timing gears, pistons, bearings, rods,... the costs skyrockets for sure (sheer cost of the parts plus additional hours to adjust them) .

No point in taking such a risk on unknown exhaust valves.

 

I am lucky Brexit made me search for alternate suppliers as I've recently come across Italian alternatives (Sangalli & Coppola Old Timer). From time to time there is a 50% price differences.

I am very happy with the Sangalli gaskets (a bit more expensive, but great service and quality), and will report on Pasquale Coppola once I've tested his parts. Pasquale made my brother Raphaël a sweet deal on a rear differential for his 365, and he also made me an offer I could not refuse on a mint left cylinder head. We do combine shipping, let's hope the delivery goes without any hiccup because that's a lot of value in a single package!

Time to drop the left head for the 4th time! (This is the head that was damaged by the sodium valve, made my best to save it, but have to replace it in the end.)

 

Ok so I brushed up on my very rusty chemistry and cut open one of the exhaust valves. No major dramas.

As suspected the exhaust valves are original sodium filled type. Obviously I will be replacing them all but good to know for sure that they need to be replaced.

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How did you cut it?

 

Hi Jim, I cut the valve with an angle grinder with a 1mm blade. However sodium reacts with moisture / water so I made sure everything was completely dry and then cut a few notches in the stem to expose the sodium. I then put the valve into a tin of water outside. It bubbles and fizzes (gives off hydrogen & heat so be careful) until the sodium is all dissolved. Once you are sure all the sodium is dissolved you can cut the valve with the 1mm disk pretty easily. I used good welding gloves and full face protection. Hope this helps

 

Thanks for the info!

 

Hello,

as I have the engine out, and the camshafts off - I think it is best to go head a replace the sodium filled valves.

I will be ordering the stainless steel ones from superperformance - together with new valve guides and all the valve stem seals.

Any precautions, are the tappet buckets matched to each cylinder?

 

The buckets are not matched to cylinders. Yes replace the valves.

 

Thanks. Do I re-use the same shims?

Does anyone have the complete Ferrari 400/412 WSM? The one on the blog site is missing the torque spec section.

 

No because you'll have different valve heights than you do currently.

Here's where you can over-analyze things. One school of thought I heard was you want to run the thinner end of the range shims on the exhaust valves to reduce weight. Then you have the shops that will see that as an error and tell the owner of the car that the engine builder screwed up etc etc. If you get carried away and make all the heights the same so all the shims are the same you could end up having to buy shims from multiple places to get that many of the same shim.

I ignore the thin shim on the exhaust valve approach because these aren't race cars and settle on the 4.15 plus end varying them so there's plenty of room for adjustments down the road and finding shims in stock isn't an issue.

Whatever you do make sure the machine shop pays close attention to setting the heights as per the WSM or you'll be in a pickle setting lash.

And after the lash is right on the bench check it again once the heads are torqued on, I wont be surprised if some of them change.

 

Can you stainless steel valves be machined to match the heights?

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Hello,

I was able to read the numbers off the valve stem: EL10782M86

Any idea if these are new or old?

They are very magnetic, as opposed to the intake valves which barely react to the magnet.

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