Originally Posted by afm
The real head clearance of these new based Picco engines can be calculated as follows:
Real head clearance = Thickness of head shims + 0.05mm*
* (that‘s due to the internal construction of the engine and the compression of the head shims, when the cooling head is mounted)
Adjust the shims depending on nitro-content (see table)
Nitro content: 16% 20% 25% 30%
Real head clearance: 0.45mm / 0.45mm / 0.55mm / 0.65mm
Head shims: 0.40mm / 0.40mm / 0.50mm / 0.60mm
Large tracks may require an extra 0.10mm shim to reach higher top speed and improved fuel consumption, but this will decrease acceleration slightly.
AFM
This information is inconsistant with what is in the manual. The engine comes stock with a .20mm and .10mm shim (.30mm total) for use with 20-25% nitro. They recommend adding another .10mm shim (.40mm total) for 30%. Where did your information come from?