Now I see a different topic but before it was MM M42 which is totally off topic now since he'll be doing it on his own. So in that case...
Here's my take on camming an engine. I'm not an engineer or a crazy car guy...just trial and error and talking to people who actually do design cams for specific parameters for engines.
The profile that I chose should get me close to what I wanted without having to weld up the cam. Basically, they cut what they call a 250/250 but for better comparisons, I would recommend looking at duration of lift above 0.050" or greater where flow starts to occur. This cam registers 222 degrees of duration at 0.050" lift versus the Schrick 256's 215 degrees and the MM 258's 224 degrees. Running this 250/250 combo will get the most powerband out of the car without having to weld up and nitride the cam. Usually when offsetting the cam timing greatly, you're going to lose somewhere if you find any gains depending on your build. A cam that makes little power below 4500rpm could mean LOUSY gas mileage and that lots of people are gonna beat you off the line as you try to get past 5K. Using a 250/250 combo will give you a very strong low and midrange powerband but yet let you pull strong to about 7500rpm. You can get a cam that pulls to 8000rpm, but I wonder if the power is flat or whether it is still climbing. Those types of cams seem to pull forever but the car never feels like it is pulling hard but just high, no grunt! This 250/250 cam set will make it so you don't have to always drive like an a$$hole to feel fast, hahahaha! And I'm not saying that there aren't other combos that will work for other compressions or displacement, it's all about matching parts for the build from the top to the bottom and vice versa! This set was designed to optimize my set up at 10.8:1 for daily driving and will probably also work for an array of other engines as well.
So one should really look at lift and duration to be related. If you have a lot of lift and no duration, you will have a lobe that looks like an arrowhead. That lobe will beat the heck out of your valvetrain and eventually the cam itself. This 250 cam is similar to what Schrick did. They use a 0.408" (10.36mm) and I used a 0.405" (10.29mm). The 250 is a bit more radical though as there is more duration at 0.050", 222 versus 215. With a long duration and high lift cam, one would need 11.25:1 and above to extract a decent idle and power up top. I didn't want to have that high of a compression engine for my daily driver so, these cams end up being perfect for my 10.8:1 compression and for that fact, they don't have to be welded up which is a whole other ball game.
So who wants lots of compression? Who wants lots of Horsepower? Who wants lots of cam timing? Well... we all sorta want that all don't we? But there is a trade off. Big Peak numbers and lots of compression due to lots of cam can be misleading. You don't want an engine that's very peaky.
As an example: So who votes for 220RWHP?? How about 240RWHP?? Or the Big Kahuna 280RWHP??? Look at the comparison of these S14 motors (Not mine). You don't want the high power one. LOL You will definitely be left in the dust......
Looks like I should build another one maybe with _ _ _ _ _ / _ _ _ _ _ _ _ _ _!
Cheers,
~Ralph
