Well, i have finally put the new engine in my 405 and have had it on the dyno today.
This engine has Cat Cams with vernier pulleys, original valves, upgraded springs and retainers and solid lifters. The bottom end has been ground 0.3mm undersize, nitrided and balanced. I have installed PEC steel conrods and Wossner pistons (11.4:1). The intake manifold and quad throttle bodies are from my older engine and are Jenvey 38mm TBs. I also have the dry sump on this engine.
While tuning the engine today, we determined that the intake tract needed to be longer - distance from the air cleaner to the trumpets. Adding 500mm of 3" pipe in the inlet made the intake manifold pressure much more stable and increased the peak power by a couple of kw.
After running the engine under load for 3/4 of an hour to run it in, everything looked fine so we proceeded to load and tune the engine.
I can guarantee you that we have reached the absolute maximum capacity of the fuel pump and injectors on this engine. The fuel pump is original, but pressure decays rapidly above 7,000rpm and at about 7,750rpm the injectors hit saturation or 100% duty cycle. As a consequence, we have dropped the rev limiter to 8100rpm with a soft cut that comes in at 7600. Hopefully I will be able to feel this on the track and not run the engine into a lean condition.
Next step will be a surge tank and higher capacity fuel pump + upgrade injectors.
Net result is 138.3kw at the wheels running standrad 195x55x15 tyres. This is at 7,600RPM. Torque is remarkably flat so it looks like she will pull through the 8000RPM mark easily. Looks like the mechanical components will probably see 140kW at 8000RPM when I can get the fuel system to keep up.
I'm pretty happy with that outcome. Will add the dyno chart shortly, will need to re-trace the graph as
it didn't scann all that well. You will also see where I have added some tipex - we were using injector pulse for RPM reference, and consequently when the injectors go to 100% duty cycle, you loose the RPM speed reference...