Welcome to Bullfrog Motosport!
Continue Shopping
The 356 is capable of extreme RPMs. With its early valve opening, larger lift and wider duration, it's a proven winner. Upgrading the valve springs, a billet connecting rod, and billet flywheel are mandatory. A carb with a 1.41" or 36mm venture or larger is highly recommended. The use of big valves is also recommended. Tool Steel Billet cores are the best choice in high RPM applications. The two piece design of the Tool Steel Billet core allows you to advance or retard the cam to meet your application needs.
Specs Engine: 390cc OHV Clone 13HP Recommended Class: Modified / Open Target (MAX) RPM: 7600-7800 Spring Pressure (In / Ex): 65 lbs Dual Spring Valve Lash (In/Ex): .003" Ignition Timining: Pump Gas Not Recommended 110 Octane 34 Deg BTDC Methanol 38 Deg BTDC Compression Ratio: 12.5 to 1 or Higher
Profile Intake Exhaust Open: 51.6 BTDC 94.0 BBDC Close: 93.5 ABDC 54.8 ATDC Lift: .3555" .3555" C/L: 108.0 ATDC 108.0 BTDC DUR @ 50: 254.3 Deg 254.5 Deg