Little bit of history, purchased an ex Japan Saturno which isn't road registered and has been used for racing in the New Zealand Bear's and Cams racing series. I intend to race the motorcycle and to date have had a larger radiator manufactured, this is 30mm wider and the core is an additional 10mm. I've finished the running gear and have sourced a fibreglass replacement seat, fairing and smaller capacity fuel tank.
I've recently received a delivery from Bob Wright. The parts included a Nordwest barrel, piston and 2nd hand head. Comparing the two cylinder head's and their similarity, I'm considering fitting the Nordwest valves to the Saturno head. The reason for this, to fit the Nordwest head to the Saturno frame, it will require frame alterations or a single carburetor to twin port inlet manifold. I'm concerned the air flow through the one into two inlet manifold will restrict the performance.
Has anyone fitted the valves from a Nordwest head to a Saturno head? Is the air flow into, and the exhaust gasses out of the head restricted as the larger valve seats won't match up to the smaller Saturno head internal galleries? Is there sufficient metal in the Saturno head to open up the internal galleries to accept the larger valves?
Does anyone have any dyno readings for before and after the conversion?
Any comments gratefully received apart from the obvious, alter the frame!!