Camshaft Selection Information

Rat Bastid said
Vizard frets WAAAAY too much overflow lift flow. He has since…who knows?

He did a series of articles back in the late 1990’s. In fact, it was is Super Stock & Drag Illustrated before Hot Rod bought it and killed it. It was 4 parts and I’ve never seen the 4th part.

At any rate, he was using a Quadrant Scientific flow bench, and as far as I know there were only a few made.

His theory was he was going to use a 30 degree seat and make more power than a 45 degree seat. As I said, I’ve never seen the last part.

I even PM‘d him on Speed Talk several times probably around 2006-2007 and he never replied.

If low lift flow was a determining factor in producing good, useable horsepower no one would ever use anything steeper than a 45 and that would be Comp Eliminator and Pro Stock stuff.

One of the first things I learned with my flow bench was most of what was published and is still being published is bullshit.

You can drop a ton of power right quick with a bunch of bad low lift flow.

What’s bad low lift flow? Flow the head backwards and it’s easy to see.

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.