Stu,

i read your explanation with much interest. Thanks for taking the time to write it.

I have one question:

"Another problem with early intake valve closing that most people do not consider is that if you have a high compression engine, say 10:1 or higher, you will have more pumping loss trying to compress the mixture. This might even lead to head gasket and / or piston failure! "

How can early intake valve closing allow MORE mixture in that results in a high compression issue and increased pumping losses. Surely shutting the intake valve early will allow less in and therefore less compression issue, less mixture to create pumping losses?

My thoughts are this is a typo and the line should read " Another problem with LATE intake valve closing "

I would be interested to clear this up, however I notice no-one else has mentioned it so perhaps the context was lost me at some stage!

Cheers

RW