ES2 exhaust valve

I got mine in stainless from G & S valves. Yes, the Exhaust vale should be non magnetic if you want it to last. It will also stand up to Ethanol 'pollution' better in stainless.

I don't know why dealers supply only magnetic valves for singles? they don't do this for twins.

By chance, I have a pair of G&S WD 16H valves on the bench at the moment and they are most definitely not magnetic.

Bearing in mind that the valves are dimensionally identical, it is probably more economic to stock only the one type for both in. and ex.

G&S"s site makes reference to the unsuitability of austenitic valves in cast-iron guides unless the stem has been surface-treated. Is it possible that some suppliers are unable to do this and therefore do not use austenitic steel.

The other thing to note is that 214N (austenitic stainless steel) is not compatible to run in cast iron guides without a surface treatment on the stem e.g.: plasma nitride, chrome or tufftride, where EN52 or inlet (magnetic) material without a treatment is acceptable. Nimonic 80A is also not compatible to run with cast iron guides without a surface treatment on the stem e.g.: plasma nitride or chrome, but is acceptable to use unleaded fuel without an armored seat.

Hi.

The 1950 & 1960 Norton parts list gives the same number for both valves. I last got mine (1960 ES2 I've had for 36 years) from RGM and they must be coming up for 20,000 miles by now with no problems. RGM & Norvil do oversize guides in bronze too if needed. Once carbon starts building up on the exhaust stem the valve will start to stick.This happened to my ES2 years back but apart from that andone broken valve head20 years ago I've had little trouble regards valves.

Regards,

Ian.

Previously andy_marks wrote:

I've taken the head and barrel off of my '51 ES2 to sort out the leakiy head joint and discovered problems with both valves. The inlet looks like it has picket up a few times, the bike only has about 1300 miles on it since complete rebuild so I'm hoping this happened early on and has freed up with use, I've certainly not had any symptoms for several hundred miles. I think I could get away with polishing it up a bit and reasembling. The exhast valve seems to have the opposit problem and is running too loose, it looks like the gasses are blowing up the stem and theres a layer of carbon all the way up the inside of the guide.

I showed all this to the engineer who is going to machine the barrel and head to do away with the head gasket and he said I should have a non magnetic exhaust valve. Both of mine are magnetic, they show up as the same part number in the book I have and are sold by suppliers as inlet and exhaust valves. But reading this forum and talking to said engineer, it would appear I need a non magnetic exhaust valve (presumably a grade of stainless), and probably slighty better fitting valve guides.

I have no issues making a valve guide to ensure it is spot on, but does anyone know where I can get a valve from? And can anyone comment on why the parts book says they are both the same, the suppliers only sell one, but it would appear they should be different.

Finally, should the stems be different diameters to give different clearances on the inlet and exhaust?

Thanks in advance

Andy you can also get valves from russel motors i,ve been using them for a few years now with no problem.used a anti magnetic for the inlet as well just buy two of the same.

Les at Russells told me that they sell G&S Valves (for the 16H, at least).

They're really nicely finished when compared with NOS. The stems have a plasma coating so they should indeed be suitable. What make are your failed valves ?

Hi again.

Thoroughly reccomend Russell motors. Always had good stuff from them at good prices and often within 24hrs through the post.

Ian.