I like reading your posts on the subject of headers and cams, do you prefer a single pattern over a split pattern? i have had good success with single pattern cams, plus engines we have done for customers.
I usually prefer a single pattern cam. Part of all the split pattern/wider than should be LSA is guys just don’t get their carb(s) in shape. So they take out intake duration. Or they add exhaust. Which ever way you want to look at it. And then they open up the LSA to get the high RPM power up. And all that does is kill power in the middle. And it makes the engine less sensitive to tuning changes.
I can’t emphasize enough the importance of overlap flow on in-line wedge heads.
Flow bench testing heads is a great way to learn how poor overlap flow is on these heads. If you look at a graph of the cam lobe profiles and look at the overlap triangle you can clearly see that overlap flow is affected much more by how far the valves are off the seat than how much time (duration) they are off the seat.
I don’t care who is doing the port work, but looking at lift from say .150 and lower you can grind and back cut and fluff and buff and you might gain 2 CFM. Maybe. The curtain are is so small that getting any air through there is tough. And most of all that grinding and **** does more damage than good because you most likely are increasing reverse flow. And that’s a big deal.
Since I have moved on from 45 degree seats and do mostly 50 degree stuff I run tighter LSA’s yet. It’s all about the shape and the 50 degree seat (IMO) is far better than a 45.
You just can’t look at flow bench numbers or you’ll hate a 50 degree seat.