Cylinder  info for PVP 252 Motor

Then you use 120 mm. rod in your PVP motor, will I recommend that polish channel and small exhaust port's if they are raw is there a risk that the hot air not come long enough out in the exhaust pipe, and the piston will be to hot and seize, and you will also get the max power out of the motor. 

That is a raw cylinder

Here is the cylinder polish

The way can you polish the inside of the channel

The way can you polish the round edge of the exhaust

I use a bevel gear to polish the cannel, is is very important that you only small stone, do not use a cutter, you can very easy damage your cylinder so you not can use it, there is a very thin wall between the transfer port and the exhaust port, and if you go true this can you not use the cylinder.