valve train...

[Tailites]

if you have ever wondered what torture the valves/springs need to take...

check it out...https://www.youtube.com/watch?v=_REQ1PUM0rY

notice the valve stem shakes back & forth at high RPMs

[ZR]

Amazing they stand up as well as they do.

[Tailites]

yes...& I know you love NASCAR Rick...

putting it all in perspective...

think about how long a race is on the big tracks & the RPMs...

[ZR]

Especially the abuse of spinning 9k plus for a 500 miler.

[RedSN]

the valve rotation keeps your valve seats nicely lapped

[Tailites]

the valve rotation keeps your valve seats nicely lapped

ya...that was a surprise...you wouldnt think it would spin like that

[tulowd]

Also explains why you don't handle valve springs carelessly expose them to chemicals or drop them......they are the most highly stressed and delicate part of a (hi perf) engine. Dropping one will cause the outer surface to have a small defect that will eventually stress crack the spring and cause failure.

Interesting that there is no mention of harmonics, which is another major cause of spring failure - brought on by incorrect combination of parts. Comp Cams website has some very interesting tech about that; as well as moving mass definitions. This is really high tech stuff; and unfortunately not understood or appreciated by the masses of enthusiasts.

Side Note: Despite the extra weight, PSP insist we run dual springs on our road race motors, so if by chance a spring breaks, the second one will prevent the valve from dropping.