At this point, it’s changing SLIGHTLY but I have to do some testing to make sure I’m not going down the garden path to the bottomless rabbit hole.
I pick my @.050 duration based on (mostly) stroke length, then bore size and where I want peak torque to occur.
My math says most of the cams most of the cam grinders calls out doesn’t have enough timing. So they do the easy thing, which is throw some exhaust duration at it (although maybe with some testing I my be slightly LESS opposed to it) and blow the LSA out to get some RPM out of the engine.
And they do that KNOWING they are killing the middle of the torque curve (which is really where all the “street” guys want their power and they bellyache about not enough torque and then they buy a cam that kills power in the middle) because they think (maybe they know) the end user isn’t capable or won’t take the time to clean up the idle and tune the carb and distributor to make the right cam work.
Most of the lobes these cam grinders call out don’t use near enough lift.
The LSA is almost universally too wide for the application.
The @.050 timing is usually not enough and the seat to seat timing is way too long.
