sodium filled exhaust valves

[L3-VDT]

does the MS3 have them? I've searched and searched...

 

[Darth Vader]

I'd be surprised, that's an antique technology dating back to 1930s aircraft engines. The availability of better materials today makes the use of sodium filled valves charmingly anachronistic.

Darth Vader

 

[L3-VDT]

most turbo engines use them. The older 04-05 STi had them, the cobalt ss has it, I'm pretty sure the evo does too, etc...

 

[Darth Vader]

Sheet man, I know turbo cars in the 80s were still using them but, nowadays, still? Christ, that's liike running a magneto and carb.

Darth

 

[dkswim]

and magnetos and carbs have there advantages.

 

[L3-VDT]

Do what do they have now that will do what the sodium filled will do?

When subaru deleted it in the 06 year they didnt replace it with some new magic valves they just did away with it, saying the new scoop design cooled the engine enough that they didnt need it... along with the cool plastic motor mounts, they ruined the sti for 06.

 

[cbspeed3]

the z06 corvette has sodium filled valves

 

[L3-VDT]

but does anyone know if the MS3 does?

 

[Darth Vader]

sodium filled valves are a band-aid. Yeah, they keep the exhaust valve cooler but they up recip weight in the valvetrain, hog up valuable port space with their large shafts and are expensive to manufacture. Back in the day, when good materials were either nonexistent or hyper-costly, they were a solution but nowadays, better alternatives are available.

...and in answer to the op's question, the exhaust valves are inconel...THAT's the right maaterial for today's engines.

Darth Vader

 

[PureDrive]

sodium filled valves are a band-aid. Yeah, they keep the exhaust valve cooler but they up recip weight in the valvetrain, hog up valuable port space with their large shafts and are expensive to manufacture. Back in the day, when good materials were either nonexistent or hyper-costly, they were a solution but nowadays, better alternatives are available.

...and in answer to the op's question, the exhaust valves are inconel...THAT's the right maaterial for today's engines.

Darth Vader

They are not a band-aid. They are proven technology that works and that are currently employed by numerous high-end sports/performance cars.

 

[Darth Vader]

They are a band aid that current materials technology has rendered virtually obsolete. They have all the disadvantages I noted earlier plus they are not as strong a current-technology solid valve. They were a band aid when they were devised in the late '30s, early '40s to keep multi-row radial aircraft engines running at high blower from burning holes in the head.

Darth Vader

 

[mattj3636]

why do you sign your name at the end of every post?

 

[sleeperstang199]

hes hoping luke skywalker is out reading his posts and comes looking for him lol

 

[mattj3636]

haaaaaaaaaaaaaaaaaaaaaaaaa

 

[dizzin9]

i agree. u can have it as a signature also so you don't have to type it all the time.

dizzin9

 

[MSMS3]

Wow, I didn't know how low tech and obsolete those twin turbo 420 horsepower new Audi R8's are to be still using those terrible sodium-filled valves. What were the folks at Audi thinking?

http://www.audiusa.com/audi/us/en2/...&modelLeft=42351t_0&carlineRight=&modelRight=

Maybe with better exhaust valves those cars might get what, 1000 hp?

But to answer the OP's question, I don't know if we have sodium-filled valves or not. Given the performance level of the Audi, I hope so.

 

[Darth Vader]

The folks at Audi are thinking what everyone else is thinking: "How can we maximise profit and still provide the product performance the consumer desires?" That's it, nothing more, your sarcastic assertions to the contrary.

There's always a balance between cost and performance and every manufacturer fits every part into their own particular formula. We can draw no conclusions about why Audi used sodium-filled valves because we don't have insight into the cost and performance pressures their engineers were facing.

Sodium filled valves are a solution to a problem...a very old problem and...a very old solution but, as someone pointed out, it's proven technology that works. That is one of the things desired by most manufacturers, along with being cost-effective (cheap). That's true of a $15,000 Golf or the R8.

My assumption that the ex valves in the MS3 are inconel, comes from knowing the Cosworth upgrade head for the MZR contains inconel valves 1mm bigger than stock. Cosworth knows a thing or two about building engines, just like Audi.

DARTH VADER, allcaps, just in case Luke is reading.....(enguard)

 

[Super Unique]

exactly as said previously, I wouldn't sweat sodium filled valves, if we did have them, they work just fine, as they have for many years previously on countless cars.

 

[MSMS3]

Here is an interesting technical read on why GM selected the lighter hollow stem sodium-filled exhaust valves for the LS7 valve train over the heavier solid Inconel valves. Yes. Sodium-filled valves are lighter and produce lower reciprocating mass and require lower spring pressures to avoid valve bounce, a very bad thing in a high performance engine.

http://gmhightechperformance.automo...p-hydraulic-valvetrain-performance/index.html

Seems the Inconel valves began bouncing at 6200 rpm and were out of control by 6900 rpm (both numbers within the engine performance band and redline of the LS7), while the lighter sodium-filled valves were seating as well at 7500 rpm as the Inconel valves did at 6200.

I apologize for any sarcasm in my earlier post, but there are, indeed, legitimate design reasons for using sodium-filled exhaust valves in modern high performance engines. They are, with respect, far from obsolete or anacronistic.

Depending on the application and on the design considerations of the entire valve train, each has its respective advantages and disadvantages. Maybe the Audi R8's nearly 9,000 rpm redline had something to do with their choice rather than cost. Newer is not always better.

 

[sluflyer06]

Actually subaru deleted them after 06'. STI had them from 04-06 as well as the 06' wrx.