Lets discuss another engine build

nm9stheham, I do believe what your saying. But the difference in a race engine vs. a street driven small cammed engine are two different animals not to be compared.

Straightline, didn't know your chambers are 64cc. I also possibly assumed they are a iron head, which would be where I would get the 9.5-1 ratio. Add 1 full point for aluminum.
I gave you my advice on what I think is a wise & safe course. But if you want to push it, then have at it. It is something that I'm doing right now and something I know I can correct if I push it to far.

Alpha13, in general, a cam should be treated to the compression ratio that has it working at its best. When is the ratio to low or high. When the engine doesn't run. Where is the perfect ratio for the cam? The manufacture has guidelines that should be looked at and followed. Though it should be understood that each manufacturers guideline maybe a different thought in there head.

Compare CompCams descriptions with CraneCams descriptions and note there very different for the similar cam by the other. You would think one is nuts. If you have never read Cranes suggestions, they list compression ratios and cruise speeds a good bit higher than Comp does. Now go compare it the other cam companies

I'll save you some time for the lesson and say there is a large operating window in which a cam will perform really well in. You just have to remember that your octane limited. The cams description of peppy vs. doggie can be a issue of splitting hairs or a serious performance gap.

nm9stheham's testimony is I'm sure 100% accurate for his vehicle. He keeps mentioning it as proof. However his race engine is a different animal and so is his cam. While someone, anyone here will say an engine is an engine and they respond the same, I say true to a point.

I still stand behind what I said about how much or little you will feel or not. My butt dyno doesn't have a huge memory storage as to keep excellent track of what one piston change feels like compared to the next. LMAO, I don't change pistons that often.

I just find feeling a 4.5% change in power which I showed the above calculations to be something I would feel much less whoop and holla about. Which leaves me with this question for everybody, not that it has to be answered by anybody.

How much of a victory margin will be shown at the end of the 1/4 mile strip with an additional 20HP? Let's just use 2 identical '70 Dusters for the example with the one exception of the compression ratio of one of the cars being 1.5 down on ratio on the posters intended XE268 cam.