Cam numbers, what do they mean?

[400awhpgsx]

Well I've searched around quite a bit and haven't found my answer so here's my question. What do the numbers in cam sizes mean? For example, I know of the hks 264s, 272s, and the 280s. What do these numbers represent? And what number would best represent stock 2g turbo cams? I'm just curious of the difference between stock cams and the cams I previously listed. Thanks in advance!

 

[Diplomat]

"Well I've searched around quite a bit and haven't found my answer so here's my question. What do the numbers in cam sizes mean?"

The numbers you see advertised [are meant to, but don't necessarily] represent the camshafts' duration. Of course, there are other variables to consider in a camshafts design. However, for quick and easy reference, some camshafts are often referred to by their make and duration; HKS 272, for instance. In fact, since the HKS camshafts are so popular (having been around for so long), you'll often see them referred to as simply 264's or 272's without even bothering to credit HKS. Perhaps that's because HKS gets plenty of "credit" when you pay for the suckers.

These days, when seeking out a new set of bump sticks for your 4G63, you'll find that the selection has grown quite a bit since the days HKS arrived on the scene. Very few of the newer camshafts are known by their duration. Forced Performance, Crower and Comp Cams, among others, do not use duration to reference their cam offerings.

There's plenty to read on the subject and camshaft selection has become almost as much about personal preference as it is about engine setup and racing style. Reading the tech article above will help get you oriented on the subject. For now, at least you'll know what the hell people are talking about when you see those numbers.



For bonus points, here's a link to Automotosports' Famous DSM Camshaft Comparison Tests.

Yet another: linkage. This is an old review but the author entertainingly gives you some idea of what kind of idle to expect from certain camshafts. Of course, there are a number of home videos floating around now that will give you a much better description.

 

[400awhpgsx]

Awesome! Thanks a lot for the info. I'm still confused about how stock compares to these other cams. More specifically, I am putting on an evoIII head and I understand the cams are close to 264s. So I was wondering what to expect somewhat.