Turbo Mini Forums

Hi. Thank you so much for your replies. I've finally decided on the 21253 piston and will machine the crown and lip to lower the compression height and get around 11/12cc. The goal is to reach a compression ratio of about 9:1.

Now my question is about the piston-cylinder clearance. The piston head indicates a clearance of 0.03mm, which is about 0.0012". Personally, that seems like a very tight clearance, and I assume it's designed for a stock engine. I don't know if it will work well in a turbo engine. My intention was to increase it to at least 0.05mm or 0.002" to avoid seizing. What are your opinions on this? I know these pistons were widely used in turbo builds around here.