We just bought 2 Volvos with D12's. They are supposed to be set at 425hp, and there governed at 65mph. When we take them to get the speed governer raised can they turn the fuel up or is it mechanical? How many horsepower would be safe?
I'd say about 480 hp is safe with these engines, I chipped 460's to 520 hp before and I had problems with overheating, I was told by a Volvo 'expert' that the only way to overcome this is to bore the waterports in the engine to allow more coolant to get through, I just had it reversed and left them alone.