Which years had Sodium exhaust valves?

I thought it was all the 2 valves, but what do I know I just fix them. You might give Ted Rutland a call, thats the kind of question one of the old time parts guys might know. If you call, ask for Ted or Brian and tell them I sent you because I knew they had nothing better to do.

 

1979 to 1982 inclusive, on 308's and Mondial model that I know of for sure.
IMO, if you have one of those "lucky" ones, and records do not show a changeout. You ar correct. It is a Time bomb.
FYI, they become brittle with age, and were not at all flexible to begin with.
To be blunt, they do not bend. AT ALL! they break off and wreck havoc. This can be very excpensive when the beads get a beating, not to mention the particulate matter caused by the broken valve going thru the piston will give you the basis for a compete overhaul.
HTH
Kermit

 

Why should they be a time bomb? Other car companies have used sodium filled valves for years. I have a 24 year old car (145K miles) with sodium filled valves. Never heard of one breaking on any of their websites similar to this website. Come to think of it, I think I have 98 sodium filled valves. Don't know about the head on my Porsche; it is not a factory job.

If Ferrari valves are breaking, then they were not designed correctly.

 

The interior deterioration of sodium filled valves is a well known problem. It does not seem to strike all all cars that have come equipped with them over the years. I happen to know that a lot of Ford 427 SOHC motors blew up for that reason. If your position is that the Ferrari valves are not designed correctly, that may be true but then all manufacturers have their weak and strong points. Porsche at one point in time had badly designed chain tensioners that damaged a lot of motors and for me to deny that problem would certainly not mean that it never happened.

 

Pontiac used sodium filled valves in the 4.9 liter turbo 301 V8 in 1980-81. they are not worth the risk they pose, and should be replaced.

i thought ALL carb and injected 308's ( 2 valve ) had the sodium filled valves , if they were sold in the USA new. euro cars did not get them until 1979 or 1980. i hope i am wrong! i just did the belts ect on my 77 gtb. i have been wondering about the sodium valves myself. great thread subject.


others ?

 

"I thought it was all the 2 valves"

I think you meant BOTH;

"I thought it was both valves."

 

How about 1982 Boxers?

 

I'll ask Randy, at Continental, to confirm the timing but I too believe it as 79 - 82 (2v) and an emissions related piece.

The issue, as I understand it, is that they become brittle from lack of use. If the motor has got plenty of miles on it and is regularly used then I do not agree that it is timebomb (this was an engine builder's view). If either of the conditions is not present (i.e., few miles/infrequent use) then I would concur that the ex valves should be replaced.
Philip

 

I work on a great many Boxers and have done so since the 512's came out. I have never seen a failure on a BB but the fleet of BB's is very small compared to the fleet of 308's and considering the number of failures we have seen on 308's I don't believe that would statistically eliminate the BB's.

I am not a metalurgist but from my understanding of the process involved I can think of no reason why the problem would not apply equally to cars that are or are not driven regularly.

Of the cars that I have seen or know of directly that have had this failure I have seen no pattern that would support the contention that it only happens to hanger queens.

 

I have never heard or seen a 512BB valve break. It is kinda strange to me as to why they break in the Dino's and the 308's..but not the Boxer, as they are from what I understand, the same valve.

 

I have worked on many ferrari,s with sodium cooled valves. 365Boxers drop them. Its not hard to lookat the valve without taking head off to check. I did a report on construction of these valves if anyone is interested. If you have them and you have a passion for the car replace them.

 

While reading this thread, I wondered why engine developers use sodium-filled valves. The 10th hit on a Google search provided a concise explanation that I'd not seen before:

Construction and design considerations are very different for intake and exhaust valves. The difference is based on their temperature operating ranges. Intake valves are kept cool by the incoming intake mixture. Exhaust valves are subject to intense heat from the burnt gases that pass by it. The temperature of an exhaust valve can be in excess of 1300°F. Intake valves are made of nickel chromium alloy. Whereas, exhaust valves are made from silichrome alloy.

In certain heavy-duty and most air-cooled engines, the exhaust valves are sodium filled. During engine operation, the sodium inside the hollow valve melts. When the valve opens, the sodium splashes down into the valve head and collects heat. Then, when the valve closes, the sodium splashes up into the valve stem. Heat transfers out of the sodium, into the stem, valve guide, and engine coolant. In this way, the valve is cooled. Sodium-filled valves are light and allow high engine rpm for prolonged periods.

Based on that explanation, I'd hesitate replacing sodium-filled valves with a solid version -- could cause more problems than it fixes.

 

Hi,

All carbed 308s ('76 - '79) have sodium-cooled exhaust valves (not sure about the early injected models). They have a much thinner wall than solid valves due to the fact that they are "hollow" and filled with sodium. The metal becomes embrittled with heat. Other than replacing them, the next "best" thing to do is always ensure they are adjusted properly so they can fully seat and shed their heat into the head.

Thanks,

Anthony

 

I tend to agree with both statements.

As for a earlier comment about the non advviseability of getting rid of sodium filled valves, modern materials are substantially better so that sodium is no longer required in almost all applications.

I have factory parts books for almost all of the vehicles in that age group and in the next couple of days I will take the time to look up the part # for ex valves for all the cars. None of them will note construction but if there are more than one type of construction the # will be different.

 

106553 has been in use since at least 76. If you can investigate what the earlier numbers are for that might be interesting.
Here is what I found, all from original factort parts books.

76 365GT4 BB 106553
78 512BB 106553
82 512BBi 106553
78 308 US 106553
80 308 GTB+Si 106553
80 GTB+Si US 106553
81-82 GTB+Si US 106553


Here is an interesting part. I thought 400's used the same valves but in the book both they and the 412 specifically refer to the exhaust valves as sodium and have a different part # of 107082

I just checked McCann's site and 107082 crosses over to Daytona and C4 so I was wrong they are not the same as 308 (thats why I'm not a parts man).

I would also like to add that Daytona's, C4's, and 400-412 series have not earned a reputation any more than any other Ferrari for breaking valves. It is a problem that has been happening to a small (very small) degree to all Ferrari motors that I am aware of since the 250's.
Maybe what we are seeing is just due to the huge fleet (in comparison to all previous models) of 308's.
I am not saying anybody is wrong here, quite the contrary, I know there is a problem I just don't know how big. Maybe it is like a doctor once told me, "We will all get cancer if we live long enough".

 

I was told that the sodium valve failures were mainly triggered by air injecton, and this shold be supported by different statistics between Europe and US.BTW most Alfa Romeo used to have sodium valves in the past, and that was not the main defective area..

Any evidence supporting this?

 

That would make sense as all of the early US spec 308s had air injection whereas the Boxers only had it added if imported to the USA and EPA converted . And, most of those Boxers that had air injection added, the owners removed it once they got their DOT and EPA certification letters or at the first engine out service. That would explain why you never see a sodium valve fail in a Boxer.

 

Daytona's and C4's have air injection. I have seen 250's break valves, and they don't have air injection.

 

in the GM motors lmitted addition ZZ430 thay come with sodium in the exhaust valves just my input