A hopefully quick answer here. the 2 degree difference between a 110 and the 108 used is about 15 hp and 15 lbs-ft minimum.MadBill wrote:Good question, and it also touches on the near-universal cam company recommendation of indexing at 4° advance. The companies' typically-wide LCAs are thought by many to be a move to save guys from themselves when they go too big on duration. Where does the '4° advance' advice really come from?
This engine was dynoed with an adjustable Jesel belt drive on so the cam advance could be set optimally. Flow tests of the heads indicated the advance would need to be 5-6 degrees not 4. Dyno testing showed 5 to be the best. This extra advance is needed because the flow ratio of intake to exhaust is changes when the smaller 1.9 inch valve is use instead of the 2.20.
The 4 advance given by the cam companies is the average value of every domestic V*8 out there and usually only applies if the valve seats are typical 3 angle designs.
When I asked Harvey Crane why so many of their cams were on such a wide LCA he said it was to retain drivability when the customer insisted on using too much cam!!!!!!