1934 250cc valves

[RKettle]

The valves for the 1934 models are not available and so I have purchased the post 1936 valves, which are longer at 105mm. I need to shorten these valves to the same length as the earlier valves. Does anyone know the length of the earlier valves part number 450-33 and 420-33.

[Roger Gwynn]

Sorry, I have dims for most Ariel valves but not those, would they not be the same as 350 ones with smaller heads, which would be easier to modify. The 1936 parts book only lists a change to the inlet valve.

[Andy H]

I think I have an open valve 250 head somewhere,if not I know i have a complete engine,I can measure them for you if nobody else can help.Where in the world are you.

[paul.jameson]

I have a selection of new 250cc valves which came with my 1936 project. I will measure them for you to see if that provides any guidance.

[paul.jameson]

I have 2 new valves, but have no way of saying for certain whether they are inlet or exhaust. One has a much deeper head than the other and is 101.1mm long but has no markings on it. The one with the lighter head is 100mm long and has VK on the head. I have a used valve 100.2mm long with V18 on the side of the top of the stem. I guess V18 is an Alpha number. I have another used valve, 100.2mm long, also with V18 on the stem. This looks as if it has been the inlet valve. I have another used valve, 100.2mm long which has no markings and appears to have been the exhaust valve.

My bike is a 1936 model LG but built in 1935 and has clearly had many items of work done on it during its life. It has sat in a shed since the late 1970s, mainly dismantled. I do have a 1936 LH engine which is still complete with head on and valves in but I shall not be dismantling that for some time to come.