2.2 vs 69S

[tadd]

There are some really nice ultra light weight 906 clone pistons being made nowdays... which prompts what may be a very stupid question, but, could I use a 906 domed piston with a 2.2 head after a light 'hair cut'?

I am planning on using a set of twin plugged 67S heads bored to 38/38, but Supertec has those nice, new, well priced(!) 906 clone cylinders with the correct spigot bore for the 2.2 heads (which I also have TPed and bored to 38/38)... thus my question. I really don't feel a desire to chase up a set of 69S heads, pay for the valve costs(!), and redo all the machine work.

I am well versed in the difference in 2.0 vs 2.x combustion chamber shape, but looking at both side by side, there really isn't a huge difference in depth or width. I have not measured the curvature, so there may be a bug hiding there.

Anyone care to take a shot at this one?

I think JE makes special pistons, but I would really like to use the ultra lights I have lined up.

tadd

[kenikh]

The valve angle is different from 2.0 to 2.2 heads, in addition to the different dome profile. You'd have to recut the valve pockets and probably flycut the dome. I have no clue what the CR would be. If the pistons in question are the ones we have discussed, you could probably have the valve pockets cut correctly from new and have the domes trimmed to fit after the fact.