2V Nightmare - dropping a valve..

Chris,

One time back in the day I ran nitrous through my 308 2v until i ran out of jets. It never blew up. When I tore the engine down to build it up hotter everthing was still in spec. By then the engine had 50k miles on it too.

 

Chris,
There's even less reliable data on the things that can cause a sodium valve to fail than there is on timing belt failures.

Every once in awhile, someone drops one, often associated with an over-rev for whatever reason.

Unlike changing belts, I don't think I remember any of the Pros recommending going in to just to replace the valves as preventive maintenance. The message I've heard is "If you've got to pull a head, change those overly fragile sodium filled valves".

 

I think that I've read every Sodium Valve post in the old and new archives and it does not leave you with a concensus on what to do. I've debated pulling the motor this time next year and doing only the heads mainly for preventive maintenance, but that did not lead to any concensus here either. For now, I shift between 6,000 and 6500 and that is plenty fine for me. I'll figure it out eventually...


JIM

 

77 308 GTB #21645 had its rear deck lid removed this afternoon with the able help of my step son. Within the next few days I hope to have the engine out and sitting on the floor. Not being one of the wealthier Ferrari owners, catastrophic failure is something I would much rather prevent than experience, so preventative maintainance is high on my priority list. This particular car has no reciepts, and no real history that I can deduce. I dont know of anything that has ever been done to it in all its 30 years.

So with a wink of an eye toward Maranello, I am going to do a full engine out service. While its out I plan to seperate the engine and gearbox, pull the heads, replace all gaskets and seals, check bearings and valves, and if God is with me, I plan to replace the exhaust valves with SS. While I'm in there, I hope to do some port matching and possibly up the CR.

The valve dropping issue has fallen off quite a bit over the years. My feelings are that most of the ones that dropped were probably flawed, and the ones that were prone to break broke early in life. Many of the other cars have already been upgraded. As Verell pointed out, there is not a lot of data. IMHO, most owners dont want a record of thier car doing it, so its not discussed or documented, but just quiestly repaired and then forgotten. Remember, if the motor drops a valve, it will do signifcant damage to the head that will require extensive welding to repair, at the very least. And people like me dont want welded heads on our car if we can help it.

Dont know how much this helps anyone. Unless you know if they are original, or replaced, you really dont know much of what you have. But I believe you would be okay if you waited until the next scheduled major service to investigate. The rear head can easily be removed with the motor in the car, and if you can even see one exhaust its possible to assume the other seven are the same.

Party on.

 

I drove mine 85K spirited miles without incident.

 

Which versions have the sodium valves?

 

The engine isn't the weak point.

I suppose if you overrev a Ferrari while in Neutral, and/or with thick cold oil, or if you already have bent valve guides, that you could drop a valve. Of course, if you have an exhaust header or valve seat leak that causes high temps behind the face of a sodium-filled valve then you might cause one to shatter and self-destruct and drop onto the piston (not good).

But a warm Ferrari engine revving high with decent engine oil while in gear at speed isn't going to see any unusual valve-dropping incidents unless there is a flawed part in the valve-train, in my opinion.


Instead, I'd think that faulty bearings or races in the trannies/differentials would see more failures than would ever be seen of Ferrari engines dropping valves.


That being said, I *have* blown my ferrari motor (debris clogged an exterior cam pulley). No big deal. Just a simple top end rebuild (which isn't even pricey if you do the work yourself).

There's a reason that Ferraris come with tool kits. Use them.

 

I think this item has been sensationalized, but not nearly to the degree of the fires. Christ, a modern Porsche burned to the ground in Charlotte this year. Most of the sodium hysteria is linked with extremely high revs. My conclusion after searching here was that the experts said if the engine is out for some other reason, then go ahead and replace, otherwise enjoy the car.

FWIW, I went through my 78 this past winter. From my measurements the #1 Exhaust, #2 Exhaust, #6 Intake, #7 Intake, and #8 Exhaust valve shims were out of spec. I measured everything twice. Car has 43,000 miles. Four owners including myself. Mileage deemed 'accurate' by a consultant of reputable reputation hereabouts. I think the car is honest. The 28 years is a lot and I have no formal records of any valve adjustments before mine. It runs good with no smoke and none even on start up.

Seamus

 

That's pretty typical for the first valve adj, a low single digit #of shims out of spec. Next valve adj you'll probably only find 1 or 2 shims needing replacing. However, by the 3rd adj, & certainly by the 4th valve adj., valve & seat wear will begin to take their toll & you may see quite a few needing replacement.

Valves stretching per se hasn't come up before to the best of my (admittedly ageing) memory.

IF you're loosing a lot of sleep worrying about your 2V's sodium filled valves, AND can afford to invest the time or money, THEN pull the heads & replace the valves. At that point the cost of port matching the intake runners & headers with the head ports is a trivial increase in cost. Of course, once you've done changed out the valves, You'll probably start loosing sleep worrying about something else happening to the car.

 

I think the consensus is "never reinstall one".........Like Mr. G, I have driven a lot of miles across my three '76-'77 cars.

Even drag racing, I observe the 7800RPM redline.

I have also missed a 1-2 shift and seen 10500RPM, revving without load.......I wouldn't want to make that a habit.

We had an Australian 308 drop one on this website, and a Boxer owner that had just rebuilt heads and he was MAD...giving rise to the 'never reinstall' motto above. That shop should have installed SS or titanium as a practice.

I think the air injector pumps 'breaking' is the best thing for them.....
It cools things down on the exhaust side of the head.......

 

I think mine is the Australian 308 that dropped the valve that Bubba mentions. It is a '77 308gt4 so in 2003 when this happened it was 26 years old. It was very low mileage at the time (under 20,000 miles) and the day it let go it was very low revs - only about 3,500rpm or thereabouts and cruising. I have posted here and there about this experience but "NEVER REINSTALL" is terrific advice and if I had only known what was to happen then I would have spent the money up front and saved myself a small fortune. Reading as much as I have on this subject suggests that there is a 2 metal corrosion issue that occurs in these things over time - but what that time factor actually is seems to vary from valve to valve and this variability probably relates to the variability of quality control or tolerances in the manufacturing of what were really quite high-tech valves three decades ago. The bottom line is that, like prostate cancer for men, it's going to come to you one day, it's just a matter of when. And on that cheery note I might stop, except to say that I'm happy to share more details or photos of the valve failure damage and the rebuld/ reinvention of the car post-trauma if you are interested.
Cheers,
Grahame

 

I remember back in around 1980 or so I bought my first Hemmings Motor News. Ohhh Ferrari's. Two 308's were listed in seperate ads with dropped valves. R&T mentioned it in some issue or another. I think it was happening with a lot more regularity back when the cars were young, and has seemingly tapered off over time. And as I wrote above, many of these cars running today have had top end work or rebuilds with SS valves and are no longer a factor. When there were thousands of 308's around, you heard about it more. Between fires, crashes, and negligence only a fraction of the cars still exist. So its probably normal we would hear about it less today for many reasons. Sadly there is no way to know what we have without a good record or by removing a valve.

Post some pics. I have a wrecked Ferrari engine file started with a few munched heads and pistons from dropped valves, etc.. Always fun to add more

Verell, thats pretty humorous, and very true. There are enough things with these cars to keep a guy awake at night saying "what if", LOL. Luckily they are some pretty tough machines.

 

Perfect! Now there'll be room in the engine bay for a proper engine

 

Where is the Best (cheapest) place to purchase SS valves?

JEGS?
SUMMIT?

(I need 8.)
Edwardo

 

There's a guy posting here 'Louthan Engineering' or something....he's doing great work it seems, and flow tests the heads once completed.......

I'm gonna send him my heads, as I get the cars somewhere for tear down, maybe Dave Helms......

Drive up, snow ski, fly home...repeat as required.....LOL!

Modern engines still use the sodium technology........

 

Holy crap!!!! I just went through everything you mentioned (except the alt. & I'm going to do the cams later). Oh yeah, It didn't affect my marriage either....

I have 60K+/- on mine, but there was a really crappy rebuild at some point in the past that most likely did more harm than good. That's the problem with these motors, any motor that's 20 or 30 years old in fact, there are a lot of "while you're in there" things that you just HAVE to do. It's just they add up much faster in a Ferrari.

Does anyone have long term usage on one of the Forza big water pumps?? I'm still on the fence about it. thanks,
Etip

 

They use to be off the shelf from Ferrea and cheap but no more

I spoke to them about doing a production run and they'd have to do enough for 30 engines (250 total) to bring the price down . . . don't think there's enough interest in a group buy on 'em is there? . . . $25-30/valve depending on blank.

I need at least a couple sets but I'm also contemplating thinner stems/lightweight retainers but then I would want to change intakes also and is there really any gains there? I've had some issues with non Ferrari springs and retainers as it is . . . I'm now at the point where I hope my big cams will work with the stock spring and retainer setup for this motor. Probably will re-visit the thinner valve stem and retainer setup again though 'cause there's something to be gained beside more rpm right? . . . parasitic losses? . . . remember when I heard that for the first time. . . thought the guy was talking about a septic tank

Thanks,

Sean

 

So, at $ 40.00 usa
for an Exh. valve, that's about fair.
(Louthan Engineering)

Even, SB Chevy Manley valves can run up to $ 22.00 each. (Jegs)

 

Louthan is indeed regrinding the whole head to resize the intake and exhaust.........all new seats, the whole nine yards......it's pretty work he's doing......I have not used him yet though....

Can someone link to his picture thread??

 

Lothian does seem to do good looking work, but he's not reporting the kind of flow gains that the mk e & snj5 are reporting their guy is achieving. Also, he doesn't use standard terminology when talking about airflow gains. S/B talking about increasing the velocity, he talks about 'volume'. It may be that he's just developed his own terminology tho.

 

So, what are they reporting for the 308 heads vs. what Louthan is reporting?
I've recieved a quote from Louthan and from what he describes will be done the $$ seem reasonable. I'm just trying to figure out how deep into the motor I want to go.
I've not read anything about mk e or snj5's guy.
Off to the archives...

JIM