Head design evolution

[Gringo]

Head design has a big impact on how well a 2stroke performs
The common design for a long time was a squish band with a simple domed bowl

Some of the later engines have replaced the dome with a flat top truncated cone, the angle of the cone and depth varies

The position of the spark is closer to the centre in toroidal designs so they probably need less spark advance

Old Bultacos had a bathtub shape, that idea has been discarded, but they have seen some merit in that design

I hope to hear your opinions

Ken

[Jeram]

Honestly, I think the dimensions and volumes have a MUCH bigger impact than the shape.

you wont get any more hp from a motor that has a well designed 'bath tub' shape vs a toroidal shaped head.

However you may start to see marginal gains if your running a GP spec motor.