should valves rotate ?

jos51700 said

How about a source? I don't generally consider it wise to take technical advice from someone with something to sell. Especially when they hint that normal operation might require more and more expensive race engine parts rather that a simple pin, as suggested in the first link below.

Link makes it look like a Manley valve brochure.

I maintain my position: http://www.cdxetextbook.com/engines/comp/vlves/valverotation.html
https://books.google.com/books?id=D...onepage&q=valve rotation in an engine&f=false

Click to expand...

Your links refer to engines with rotation designed into the valve train. They have no relevance to Tubtars engine. Some engine need valve rotation some don't. Apples to oranges.

You are right those pics are from a Manley tech page. The information is quite valid for engines with non rotational valve train such as virtually any race motor. Just because they sell parts doesn't make the information any less true. If they really wanted to sell parts they wouldn't put this info out there, and would sell more parts due people's increased engine parts failures.