Camshaft Selection Information

I think He pushed that as a way to increase OL scavenge, and pick up port velo, w/o increasing the duration as much. That would supposedly reduce the reversion event enough to "trade off". This is really small cam street stuff basically, Dulcich tried the 30° routine as well, but as Vizard acknowledges the seat load needs to be increased to maintain a tight seal & control bounce...so now You're using more spring(drag) to do the same job. Lately, Vizard has been using a 39° seat for stuff that isn't all-out. Guess that's His compromise, I'll let Him spend His dyno time proving/disproving it, I'm sticking with 45° for what I'm doing.

Hmmm…didn’t know he was using a 39. That’s interesting.

I know (until maybe recently) he was using a radius intake seat. That’s a big no no. Looks great on a flow bench but hurts power.

Actually it looks good on a flow bench flowing forward. It looks horrible flowing it backwards.

Now I’m wondering if he was using a radius with a 30 degree seat. I wish I had those old magazines as my memory isn’t what it once was.