Hi has anyone had any experience with a Megacycle 125-NRR it is a Norris spec by Megacycle. I am building a new engine for my period 4 road racer 10.5 to 1 Arias 970cc, ported, Cycle X oversize valves 29mm CR carbies Dyna 2000 ignition I am running on AV gas. I have one still in the box and was wondering if any one has any experience with this cam? I am currently using a DP315 in an engine specked the same but with wisco 915 kit. It has great top end but I am chasing a bit more torque.View attachment Megacycle 125-NRR.pdf
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amc49
CB750 Guru
Not an expert by any means on SOHC cams but in my view you won't get any midrange there. Bigger motor will help but way too much intake duration there and the bigger intake valve will only add to that issue. Intake closing point is what makes torque, that cam too long and for high rpm only. Long enough your compression effectively will not be the numbers, need more compression with the intake timing there. EFFECTIVE compression boosts torque, long intake drops that until the rpm speed intended to make up for it by ram effect then boosts it back. By then you are past the mid torque area.
Your intake lobe center is pretty insane there. Intake closing point is what you mainly feel with any cam timing change, that one says no mid torque at all, only top rpm, the DP315 much better than that one. Going the wrong way.
I've not seen that much a mismatch in durations intake to exhaust in a long time, must be a very old cam profile.
Your intake lobe center is pretty insane there. Intake closing point is what you mainly feel with any cam timing change, that one says no mid torque at all, only top rpm, the DP315 much better than that one. Going the wrong way.
I've not seen that much a mismatch in durations intake to exhaust in a long time, must be a very old cam profile.
