318 timing chain.....and why the engine should come out.

glhx said

I’m not looking at it. I’m trying to understand why the torque is high but the duration is high.

If an268 is too much......

Why wouldn’t that one be overkill.

It would seem like that range would be a 256
Not a 278

Click to expand...

Because it is advertising ...... And you truly have to understand that there are VERY subjective interpretations of what is 'good low end torque' on the parts of users. The typical low compression 318 is already at the margin of low RPM torque and it is not hard to sned it 'over the edge'. IMHO, your interpretation is right.

There is also the problem of what these slow ramp cams do for lift as they are closing and approaching .006" lift (or 'almost' closed), where he advertised duration number is usually measured. If the profile closes rapidly from the .050" lift number on the intake side and quickly get down to, say, a .010" lift and then slooowwly close to .006" and smaller, then they are going to act like a smaller duration cam. We never get the details of that unless we buy one and measure the lobe profile ourselves.