Sodium Valves ... curious to know

To (1), I would add, as stated earliler, a note about cars that sit for long periods and/or are not driven much being more susceptible to valve stem corrosion. This may be news to people who don't work on cars, their Ferrari is one of their first few "toy" cars, or the 308 is the first car in which they have heard of sodium-filled valves; but it is fairly common knowledge in that big world that exists outside of FerrariChat.

 

I still have them in all mine, and modern engines use the technology to this day.....

The effort and expense of removal and replacement "for no reason" is prohibitive, IMO.......and I have zinged one of my engines to 10,500RPM.....

Disabling the air injection is the best method to reduce heat stresses on them, and when I have nothing else to do, I'll change them all.

It is a failure at the stem/head juncture, and if you let a loose one roll off the workbence and hit the floor, they shatter like glass! LOL!

Drive on........

 

Stainless steel, heck.... titanium!!...lots of better things to make valves out of! LOL!

Dave Helms has kindly offered to replace all mine but you most likely will have to do an engine removal to get the front heads off....heavy lifting for sure!

 

Ah, the voice of reason .

 

Never use titanium valves, the ductility difference with steel is huge and the risk of them breaking is not worth the weight gain.
Where you can really see a difference is by replacing the OEM valve cups that are shimmed from above with cups that are shimmed from below. Huge weight gains and no risk of breaking anything.
Titanium can be used for conrods but there is still a risk of catastrophic failure with costs far exceeding a broken valve. Titanium conrods should never be over revved but with this disadvantage in mind the weight gain and reduction of rotating mass is huge.

 

Ask the sodium valve.
Cheers,
Tom B.
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My gt4 had it's sodiums replaced early in life. There couldn't have been more that 20K miles on her. I don't actually know if it was because one had broken though but I think that is a fair assumption. I'm happy mine have been replaced. I don't think it's fair to poo-poo this and pretend it's not an issue.

 

I told you they EXPLODE !!!

 

i have megga oil burning issue's my engine will be out in next couple of months for the last year i've been collecting all my parts gaskets, bearings, etc!! bought new s/steel oversize valves from usa + will do mild port polish on heads............... looking forward to it cheers

 

Why?

Oh Why?

 

I bought my car with a brocken motor ,308GTB drysump . The previous owner did not know how to check the oil level in the drysump ! and it ran a bearing and threw a rod . When I stripped the motor the piston had hit the head and bent the valves .On removal of the bent exhaust valve I cut it open with an angle grinder and low and behold it was a sodium filled valve bent in an S no sign of the valve head coming off . This car had 98000 km on it ? How many people know of brocken or dropped st/st valves . Are these motors not over revved the valve bounces and the valve is dropped then breaking the head off ?

 

Maybe I really am smoking crack. I currently have over $7K in engine parts sitting here in boxes, gaskets, seals, bearings, carb kits, hoses, fitting, bolts, spares, etc., I have almost a grand into crankshaft bearings alone. I have another $1600 in gaskets and seals. Pistons, theres another $1200. I have no machine shop labor or head work into this yet except liner boring ($400) and crank inspection/polishing ($240), just parts so far. The parts are NOT inexpensive in the least. And once you get started, once you have $8K or $9K wrapped up in engine parts, you just cant justify cutting corners anymore, you start doing EVERYTHING. By the time I have the heads done ($$$$), a new clutch ($700), water pump ($200+), I will have well over $10K in parts into one engine, with no outside labor. And this engine wasnt damaged in any way, im just trying to overhaul it after it burned a piston.

Long before I owned a 308, a fellow I know of spent $14K at a shop on his 2V 308 almost 10 years ago after throwing a timing belt without any new pistons or bottom end work or anything, just basically a valve repair job/30K engine out major service. Another guy on this forum, he stripped a timing belt on his 2V 308 about two summers ago and bent up the valves on the rear head. He was lucky and didnt mash up the head any, just bent the valves, and it still cost him nearly $7K in parts and cylinder head work to do a DIY rear bank repair job with the engine in the car.

So I am more than stoned enough on crack to believe that should you mangle a head after dropping a valve and go into the engine for a full blown overhaul, youll spend all of that and more if you DIY. And if your paying for labor at a reputable shop you may want to be sitting down before you consider the outcome... When you drop a valve, you WILL have the added expense of destroying pistons, a 50/50 chance of totally destroying the head beyond reasonable repair, possibly bending a rod, damaging the crank, breaking a cam, etc., maybe a 10 to 20% risk of destroying the block by splitting a liner. I actually seen an engine at TRutlands that had totally grenaded and blew a hole in the gearbox when the rods came apart. Anyone who thinks they are going to get off cheap with one of these cars after wrecking it is either smoking crack themselves, or planning some kind of hack work like in that engine Dave Helms came across with the welded piston.

So while I can agree its not something to lose any sleep over, if your planning to have the motor out for major service, it wouldnt be totally stupid to check to see what valves are in it, especially if your like some of us who just cant justify destroying the original engine though negligence. And a FYI, you CAN check to see if thier sodium with the motor in the car, at least the rear bank.

 

Artvonne....I agree it's not cheap [at all] and the crack comment he made is just childish. I bought my 308 from Rutlands...great group pf guys.

BTW...tell me how to inspect for sodium valves with the engine in the car.

 

+2

 

Time to do some parts pricing! Paul is spot on.

I can now inspect the valves, seats and cylinders with the air cleaner top off and it only cost me $7K plus numerous bribes to get a medical Broncoscope with a video monitor and 3 ft long flexible forcepts that feeds through it. Now if I can figure out how to capture an image on the laptop.... Took a lot of time (and bribes) to convince some folks in the medical supply chain that I had no intention of practicing medicine or probing various holes in the human body with the above.

The next car that gets towed in with pieces of the plug extender or the spring clip from them that feel into the cylinder when the plug was removed will be a cake walk. I suspect the pay back period on this investment will be around 10-15 years if I live that long.

Dave

 

Threads like this convince me there's a biz in just selling parts . .. anyone need bearings for 1k a set (might be able to include rod bearings for that) or a complete gasket set for $1600?. How about a head gasket for $300 . .. all "in stock" at these prices

Sean

 

My fire motor had a broken exhaust valve in it when I tore it down . . .no piston damage though . .. I have the two halves in a bag . .. maybe the cold fire extinguisher fractured it?

 

Yeah, I'm curious about this too... How does one determine / inspect what the valve material composition is with the engine in the car? I assume you also mean with the heads off and lying on the bench?

With the intake manifolds off, you can see part of the valve stem and part of the neck / backside of the head --- but, there are no id marks on the valve in these areas, not that I was able to observe anyway (as I just recently had the manifolds off my car and was looking at all the valves from this perspective).

You can reach in and put a small magnet on the valve stems and determine whether or not they are magnetic. But, that's not going to tell you much: If they are not magnetic, they are most likely made of Titanium (not on a 308, of course) or Stainless Steel --- if they are magnetic, then High Strength Steel or still possibly Stainless Steel (some SS is magnetic). But, you won't know if they're filled with Sodium or not this way...unless you want to try to heat them up with a torch and put an ultrasonic tester against them to check for internal fluid (i.e., liquefied Sodium)???

 

I already did! And if you read Paul's post again and my post againk, you will see that Paul just added up to the lower end of my estimate! And that includes things like carb overhauls, clutch, water pump, and other things that don't really count as part of a rebuild...

 

Paul -- Please do tell everyone how to tell if the valves are sodium-filled or solid. Seems like good insurance to me to just go ahead and replace them if one already has the head off, but if there is a way to tell with the head still on, that would be good to know.

 

How about with a magnet?

Although from memory both style of stainless valve I used had slight magnetism . .. I'll double check though.