The weigh-in results are in. The normal exhaust valve (9mm/33mm £) is 92g whilst the mystery ‘S’ is 76g (8mm/37.3mm). So the S one is lighter but with a thinner stem and fatter face, so not totally conclusive. I just checked what came off the 914 which should have had a sodium exhaust but there are no markings on the face at all (could have sworn there was, but no! But they are VW stamped and more than likely original). 914’s on the right (and bigger of course). Perhaps the ‘S’ means something
Or perhaps the ‘S’ means nothing. I’ll guess the 914 exhaust is sodium (dimple in the head) the other three are solid. Bus 2.0l head casting part number should be 022-101-372G with 37.5mm x 8mm inlet valves p/n 021-109-601A and 33mm x 9mm exhaust valves p/n 022-109-612D. Both Inlet and exhaust valve are solid but I have read that sodium exhaust valves may have been fitted to some heads. Sodium inlet valves were not fitted to any Type 4 heads by VW or Porsche – unless someone can prove me wrong. I fitted sodium exhaust valves to my 2316cc engine but apart from the price it isn’t easy to tell the difference - new 34mm x 9mm sodium on the left, old solid on the right.
Update on the valves business. Having mic’ed up the valves to measure for rock it turns out there is very little wear - most are within spec with only one or two just over and nowhere near the wear limit, so the guides are staying put. Going back to those pesky inlet valves, I still think they are sodium - I hadn’t noticed a deliberate and distinct dimple on them - you can just see it between the ‘S’ and the VW logo in this photo; Doesn’t really matter now anyway as I’ve fitted a new set of SS inlets from Heritage (Italian?) and a nice set of NOS exhausts picked up of eBay a few years ago. All lapped in and reassembled so time to move on to the next thing.
My mate Andy stole the school chunk of sodium, it was kept in a jar of oil. We threw it in the river Witham and after about 10 seconds it bubbled up to the top and shot around the surface fizzing away.
We used to carve off a small chunk in chemistry class, then chuck it in the sink while the girlies were doing their experiments. Instant detention
I checked in my books and basically the evidence for having sodium filled exhaust valves is a 0.2mm exhaust valve clearance marked on a sticker, with a 0.15mm inlet valve clearance. In late 1974 , VW put out a service bulletin saying the 1600 T2 engines no longer had sodium filled valves. But it doesnt say if thats on the T4 style cases or not.. And plenty of warnings in service bulletins from mid 1973 that the 1800 T2 engines do have sodium filled exhaust valves. Can only be T4 style.. Unfortunately I think my VW engine service book / folder dropped out of the system in October 1974, so no more bulletins.
Thanks for looking Mike, it confirms what I have gleaned from various sources but it would be interesting to know if that 37.3mm x 8mm valve is sodium filled. Maybe @mcswiggs could confirm by cutting the stem off a valve – safe enough if it’s kept dry.
Well, err, I could - but was kinda hoping to keep them as a spare set for the day when it’s impossible to buy replacements (can’t get a gasket set for love nor money at the moment). If someone could weigh a SS 37.5 x 8mm valve we could compare it to what my iffy one weighs at 76g - would that be proof enough?
Have you tried Schofields https://www.alanhschofield.com/ourp...Set-1820L-Type-4-Engines-7278-029198009A.html Or Ahnendorp B.A.S. https://www.ahnendorp.com/VW-Type-4...ket-Set-VW-Type-4-1-8-2-0-CJ.html?language=en
Doh! Thanks for those - Schofields is OOS, but I may just grab that from Ahnendorp. I found a set in Germany but they refuse to ship to UK now…
CSP has a gasket set available, if you’re stuck, I’ll buy it and send it on – but postage costs and customs is a hassle post Brexit and I’m not surprised some companies wont ship to the UK. https://www.csp-shop.com/en/engine/engine-gasket-set-198-009-021b-11126a.html
