If I followed all the instruction you gave on porting would there be any benefit in cutiing the turbo slots in the piston under the ring gland. thanks Dennis

Dennis,

The basic porting "How Too" does a really good job of producing competitive power.
Venting of the piston as shown in this thread: www.modelgasboats.com/option,c...tid,14/id,1668/
It is an exotic variation that does work really well. But the transfer passage shape/width is a specific shape and size to work correctly. The Piston is also done specific for the application.

The "Oval Slot" piston engine works best in applications where the ultimate in top end rpm power is wanted. Torque is less overall.

Scott

it is just for sport boating no racing so I will leave the piston as it is but thanks for the good info, I will follow your basic porting info as best I can. thanks again