While i applaud your way of thinking..
There's I've thing you over looked.
Compression**
The further the distance from valve to piston , the less compression.

Sorry this can't happen .


However if you find a way to make the valve seal while opening going up instead of down
You increase the compression, and reduce distance and solve one issue...

I'm not sure what the actual interference dimensions are. But I think you would also not be able to run a stock length timing belt with the head lifted any significant amount.

Just get a 4G64 block and use the stock pistons! The deck is 6mm taller but need the longer 2.4 timing belt, thats the easiest way to do it and gain some height

ec17pse said:

Just get a 4G64 block and use the stock pistons! The deck is 6mm taller but need the longer 2.4 timing belt, thats the easiest way to do it and gain some height

Click to expand...

I bet the compression numbers from that setup would be interesting.

SOADweskey said:

I bet the compression numbers from that setup would be interesting.

Click to expand...

Most certainly! I dont know how to calculate it but i am sure someone knows how to find it out or calculate it,

Good news is you could swap pistons to account for all that I think it's an interesting idea.. if you've got horrible issues with that sort of thing. Or you're paranoid about it.

There are two potential areas of clearance concern. One is valve to piston. The other is valve to valve.
Valve to piston is usually handled by clearance cuts in the face of the piston. In this case, they would need to be able to leave space with the piston at TDC and the valve at full extension.
The issue with valve to valve is whether the intake valve can touch the exhaust valve with both at full extension. This requires the angles of the valve shafts to be very close to parallel, since they normally all face toward the center of the cylinder bore to some extent. This angle is to deal with the size of the cams in dual cam systems generally, and port size requirements.
The smaller the cylinder bore, and the larger the valves are, the closer they end up, even when seated.
BTW, the original non-interference engine design would be an L-head. Here, the valves run alongside the cylinder, and the valves face "up". They sit in a pocket off to the side of the bore. NOT what you would call a "performance" design!