Yep, this does bring back memories of doing valve jobs.

Sodium Cooled Exhaust Valves were first introduced on the Type 2 &
4 1700/1800/2000 engines as well as the Fuel Injected Beetle 75-79.
Nowadays they're pretty hard-to-find and when you do locate 'em, darned
expensive (but worth it IMHO).  Last time I was able to find any for my
Ex-80 Vanagon was 1994, but they're bound to be out there somewheres.

For reference for those who care:

043 109 611A  Exhaust Valve, 30mm w/9mm Stem, Bug 75-79

021 109 611  Exhaust Valve, 33mm (Steel repl is 022 109 612D)
  Type 2 1700 72-74
  Type 2 1800 1975 (ED Eng ED0000640-ED0025000)
  Type 2 2000 76-79
  Vanagon 2000 80-83.5
  411/412 1700 69-74
  Porsche 914/4 1700

021 109 611A  Exhaust Valve 34mm (Steel repl is 022 109 612A)
  Type 2 1800 1975 (AW & ED Eng to ED0000639)
  411/412 1800 1974
  Porsche 914/4 1800

VW was way ahead of the unleaded fuels game by installing silicon/bronze
guides in their 1300, 1500 and 1600 heads in the early 60s to present day
production.  Earlier heads usually used cast iron guides (1965 40hp heads
[one year only head] usually had bronze guides).  A good head rebuilder
would (and I'm sure still) retrofit bronze guides into the earlier heads.
--
Jim Thompson
84 Westfalia 2.1 "Ole Putt"
73 K Ghia Coupe "Denise"
72 411 Station Wagon "Pug"
oldvolkshome@gmail.com
http://www.oldvolkshome.com
**********************************
On 11/1/06, John Rodgers <inua@charter.net> wrote:
>
> Neal, interesting post!
>
> I never knew that the V-dub engines had sodium filled valves.
> Interesting info. I note our comment about the bronze/silica balve
> guides - I suspect that is what was in the aircraft engines in my day.
> Changes in fuels - especially the elimination of lead compounds as
> lubricants for the valves in their guides on the combustion side of the
> cylinder - resulted in changes in guide materials. Engineers had to come
> up with something that would not wear out given they no longer had the
> lead compounds as a lubricant.
>
> You mentioned "sandblasting". Aircraft cylinders are a combination of
> steel cylinder barrel threaded permanently into a cast aluminum head so
> that the cylinder assembly  is all one piece - including rocker bosses
> for the valve rocker shafts. Cleaning that combination of steel and
> aluminum was a challenge. We cleaned a lot of cylinders and cases, but
> it was a rare day that "sandblasting" was ever applied. Instead, it was
> "beadblasting". One had to be very careful with the sandblasting that
> was done because the moving sand took off so much metal. Had to be very
> careful Beadblasting took a bit longer, but the materials did not remove
> metal. Walnut hulls were heavily used in the aviation industry. There
> wasn't much they would not strip off.
>
> This is all interesting stuff.
>
> John Rodgers
> 88 GL Driver
>
> Neal Barrentine wrote:
> > I haven't posted to the forum for quite awhile, but was very interested
> > in this thread. In 1980 I worked at the Bug Haus in Seattle where one
> > could buy a 1600 dual port long block for $369.00 exchange. We sold
> > over 365 engines a year, and each one of them had sodium filled exhaust
> > valves, three angle valve grinds, and the valves HAD to rotate in the
> > guides, which were a bronze/silicone alloy. My job was to pull the
> > engine, dismantle and inspect it, clean all the parts, sandblast the
> > heads, intake valves and valve covers, press out the valve guides,
> > paint the engine tin and valve covers. The owners did the easy work-
> > one assembled the rebuilds, and the other did all the machining. If one
> > of them was absent, then I got to cover for them. My favorite job was
> > running the mill machine, especially fly-cutting heads, but I learned
> > the most about physics from grinding the valves and seats. Heat
> > transfer is the key to long-lasting heads, and the grind and rotation
> > of the valves are the key to heat transfer. I had to throw in my two
> > cents, as reading this thread brought back good memories. Have fun,
> > Neal
> > Neal Barrentine
> > Bloomington, Indiana
> > 1986 GL
> > 1960 Baja Bug
>