Most of those are directed at circle track and road racers, which centerlines in those areas work great for. They are not very efficient under 3000rpm though.F-BIRD'88 wrote: ↑Wed Sep 21, 2022 3:04 pmOrr89rocz wrote: ↑Wed Sep 21, 2022 2:17 pmIt’s unfortunate the catalog cams never seem to come in under 110 lsa. Can find some under that but much more limited than the 110-114 lsa cams out there. So sucks the program gives you 104-108 lsa stuff and you still have to get it custom ground if there are cores available for that tight lobe separationF-BIRD'88 wrote: ↑Wed Sep 21, 2022 10:33 am
When you read DV's books and select the overlap as per the overlap pie chart for the intended application RPM and build level. and apply the 128 formula for that engine you get a camshaft duration. (within a workable relevent range)
Mostly biased for a single pattern camshaft.
You can then tweek things a bit if you want a dual pattern cam. This tends to widen the LSA a hair. It doesn't have to but...- it tends to-. And then you can tweek the installed position "advance" .. Don't be timid to play with this +/-.
And as DV said in his comments a Dual Plane intake manifold can tolerate a slight widening of the LSA a hair. VS what a single plane manifold is going to favour to make good torque.
It is intended as a guide for the end user to get a high torque per cid street strip perf engine.
A better but simple method VS just selecting from the catalog page.
There are lots of catalog cams that are 104 105 and 106 and 108 LSA.. You just have to look.
Check out the Isky cams stuff. These cams ALWAYS work well.
Check out the Linati / UDHAROLD "Street/Strip" cams series and the tight lash stuff.
Like I have said. Vizard’s formula isn’t doing anything special. He data fit results of engines he tested on the dyno to make good torque / ci for those applications. The problem is there is more to a cam than dyno results and no one on the street needs best power between 3500-7000rpm at WOT.