For the 33M head 24,5cc there is no need of valve reliefs and the pistons got 17,9cc, right?
The 15M head has only 17,9cc and for this head reliefs are needed because the valves are nearer to the piston top.
My question is, what did they do with the heads to keep the same shape? Itook a look at both and the only difference is the shape of the chamber (spherical and poly-spherical) the cam, rocker arms, valve springs and everything else is at the same place also valve angle is the same or else the rocker arms wouldn't fit. Valve lenght is also the same.
