Non-sodium valves?

[Tav]

I've just got back my GT cylinder had from porting. It's up from a peak 50-55CFM to over 70CFM. So a fair increase in flow ~30% and that's about the same across a wide range of lifts. It's basically flowing a lot more even when the valve is partially open, which is where it spends most of its time.

Now it was and possibly still is destined for an N/A build. But it's got be interesting to see what an increase like that could do to a G40 with the usual mods: filter, 65mm toothies, GT inlet, G60 injectors, 4 branch and a chip to suit.

Issue: it doesn't have sodium valves. Should I care? Has anyone actually burnt out standard valves on a G40 or turbo conversion? Surely the main factor to consider is exhaust gas temps. Any insight into likely differences between N/A and boosted? Suitable peak figures for standard valves?

P.S an AFH head will flow twice what a standard GT will without porting. 100CFM. Apparently the ports are really good. Brap!

[z3i]

Big valve heads on g40's arnt sodium filled
where did you get the head work done? mind if ask how much? thanks mate
Taylor

[Tav]

Big valve use a bi-metallic valve though...which are prob. more durable too.

Jason Moyle Racing - JMR Clubsport.

Price, you'd have to ask Jason. Mine was the first 8v hydro Polo head he did, so prob not representative of what another would cost. He's got a website if you google him. Top bloke! Just say Mark told you about him.

[paulg40]

Just to put your mind at ease, I recently rebuilt my wives Golf TSI (twin charged model) which came with sodium filled valves as standard however when I changed the head (due to engine timing chain failure) I had to find some new valves and it seems that even VW stopped selling the sodium filled items. So it no longer runs the standards but uses the normal valves found in all VW turbo engines from 2009 upwards which I am sure aren't anything special as they cost very little.

Had it running for over a year now and no issues. I did some research whilst rebuilding the engine as I didn't think it was right myself but it seems you need to be running a whole lot more HP before the need for sodium filled valves come about? don't quote me on this but I am sure this was the conclusion based on lots of Jap car owners not using them in 500+ HP cars and still being fine.

Hope this helps :-)