Cylinder Head - Part Cleaned

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Comment by Paul Sheridan on November 22, 2011 at 15:20

The tighter coils on the valve spring was an early attempt at preventing valve bounce or float, at higher engine speeds, also, as already mentioned, it helps to keep the valve stem central in the guide and so alleviating stem seal failure, whilst reducing friction during the opening sequence.  Double valve springs were also used to over come the problem. Now with the availability of higher quality materials, the springs are uniform.

This is an interesting vid.....   http://www.youtube.com/watch?v=_REQ1PUM0rY 

Comment by Paul Sheridan on November 21, 2011 at 21:39

That's the way i was taught, the dense mass of the valve spring to cylinder head,  although there was always a debate as to why!! some of the old boy's used to say that it was to do with heat disipation.

Comment by Dave Price on November 21, 2011 at 21:22

Do valve springs have a correct way up?  I ask as I am currently fitting new valves and springs and noticed the coil density changes from one end of the spring to the other.  I imagine dense coil spacing at the bottom, more open spring coils at the top.  Is that correct?