512 Boxer Valves

Can anyone tell me if 80-81 512 carb boxers had sodium filled exhaust vavles?
MG

 

Yes it does if its a virgin.

 

Are there replacements available in Stainless or Titanium ?

 

stainless.

 

512 BB valves are the same as 308 valves by the way. I changed my exhaust valves as a matter of precaution (as the heads snap off sodium ones).

 

From what I have been told by several Ferrari mechanics is that while the sodium valves did cause a few problems with the v8s, there have never been any problems with them in the Boxer engines...does anyone know of a sodium filled valve failure in a Boxer engine? So, unless you need head work for some other reason, it does not appear necessary to change the sodium filled valves in Boxers just for change sake...

 

Put down the crack pipe franklin, there are boxer owners here that had failures and posted threads about it.

 

Who, refresh my memory ? ...I do not recall a Boxer valve failure as a result of them being sodium filled...the only ones I recall were due to cam belt and/or tensioner bearing failure

 

My 365BB snapped a sodium valve last year. I have a good paper weight on my desk - a piston with a valve stuck in the top. As Newman says its a common problem. Ferrari actually issued technical leaflets to its dealers on the matter. The valves only have a limited shelf life as the sodium eats the metal away from the inside. If one goes at high speed - well ...............

 

There is a list of, perhaps, 100 Boxer owners on this F-Chat. It would be interesting to inquire into how many have experienced valve failure. I have great respect for Paul Newman, and am sorry to hear of your experience John Watts, but I am with parkerfe on this one. I simply have not heard of any until John Watts' post. In fact, a valve stuck to a piston, barring metallurgical analysis, could represent one of many failure events. These might include valve guide sticking, float from a weak spring, etc.

Mass production is interesting in that parts prone to failure fail consistently. With 3,000 vehicles out there, each carrying 24 valves (72,000 valves), surely a design flaw would be more evident. The same could be said for differential failure. (Don't go there Jim...not this year).

Folklore interesects engineering reality on Ferrarichat. Contrary to John Watts comment, "...As Newman says, its a common problem..." (I do not believe that Newman has used the adjective "common.") I offer that this problem is not common, and, indeed, may not represent a problem at all.

Jim S.

 

when my spanner put the stainless valves in my car,one of the old valves dropped of a bench,yep head broke off.
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George - nice car. Interesting experience with the valve breaking. Not much one can add. No retort. You got me on this one.

Jim S.

 

I agree I shouldn't have put the words "its a common problem" in Newmans mouth. But clearly Newman has heard about it not just from me. What I meant was my Ferrari mechanic thinks its a common problem he worked at the uk main dealer Marenello from 72-96 and owns his own Ferrari specialist now. Thats 36 yrs experience and 35 on Boxers. Sure its not happened to everyone and seems more common on 365's for some reason. He has repaired many Boxers that this has happened to. One car broke three valves one after the other. Maybe the problem lies in a manufacturing fault that appeared in a particular batch. Personally Ive never had one go in a 308 and Ive had five different caars over the last 8yrs. I have heard other people say they never come across the problem. But it does seem to happen unfortunately. I am definately not suggesting people take their engines appart for something that might happen. I did on the 512 because of what happened on the 365 - I just didn't want to wreck another head. Lets hear it from others it has / hasn't happen to ?

 

My boxer losing a valve is a very real concern in the back of my mind. Having a valve break in a TR isnt a known problem, nor is it in a dino or a 550 or a 250 lusso, the list goes on. 308's seem to have the biggest problem in this area and I suspect its due to the large production number compared to the boxers so it seems like less of a problem in our cars. The fact is they break in boxers where as they never do in a TR from just tooting down the road with that boxer grin on your face. Different valve design = no broken valves. Ill be changing mine because the odds of one breaking is higher than the likelyhood of me winning the lottery plus at 26 years old my car can only benefit from new valves. Ive heard of the drop test too with the same results which ill do when I do my valves. Carobu built a 512BB engine for a boxer owner here and soon after a valve broke (I forget the owner) because the sodium filled valves were reused. There have been more than 2 boxers with broken valves.

 

I just replaced mine with stainless, the valves were covered with crud, seemed pointless cleaning them.
Someone here bought a boxer with the engine redone by a very well regarded california company, if I remember correctly the sodium valve broke, company redid the head, no ones fault except an apparently good valve failed. If heads are off I say change em while you can. These valves were not made to last 30= years of sodium to liquid to soild cycles, the valves develop minor cracks and then wham. Daytonas were known to drop valves. the V8s rev higher and do more miles so the failure rate is higher. On a boxer this is an if not when ocurrence, although i am sure most would go 100k.

 

Good day all,

I, have done a little empirical research on this... What I found was that the greatest probability of value failure was either infant mortality (i.e. break when relatively new), or high temperature gradient engines and/or head rework (valve regrind). Given that our cars are no longer infants , the second statement would apply:

a. Boxer engines appear to run cooler than 308 engines (i.e. Boxer overheating is much less common than 308s... at least in the threads I have seen) and so they have lower temperature gradients which may minimize their probability of failure.

b. Valves that have been "reground" reduce the surface area of the valve contact area which increases the temperature gradient... and thus increases the probability of the failure...i.e. like the infamous soon-after-rebuild failure by a well known f-car rebuilder

Again, these are just my observations/discussions and they do not have any direct science to them so please do not flame me on this (as with everything, do as you see fit). However, my observations seem to explain to me the issues we see. In summary:

a. my car has been running for some time without problems, so infant mortality is not an issue.
b. my car has no evidence of a head rebuild... so potentially no valve regrind
c. at some point I am going to rebuild my heads anyway just to minimize startup puff, improve head efficiency, etc and in doing so the valves will be replaced.

For me the valves are an issue, but something that I am not overly concerned about.

Cheers,

Sam

 

Thinking about it most of the 308's I've had have already had previous head work so maybe that why it hasn't been a problem on these cars for me.

 

I have been told by someone who knows what they are doing that it is important to have enough valve clearance on the sodium valves.
This is to ensure that the valve contacts the seats properly to dissipate the heat through the seat itself relieving the heat soak in the valve.
Sounds logical.
Still wish mine were changed to stainless and should have insisted at major.