The bike will go to blighty and back by sea. These are trips around the Horn of Africa or through the Panama Canal. Ship travel time is 35 days. There is the trip from Salem, Oregon to the port at Gardena, Calif, too, and customs, and a little bit extra in case something happens that requires a delay. The shipping lady says to have the bike ready to go, in the crate, and picked up from here three months before we need it. This is mid February. The engine I hashed together to meet this schedule was described earlier, it is 865cc barrels from Werner's wrecked scrambler, new Triumph pistons from a T-100 relieved to provide valve clearance, and everything else is from the 995cc big bore motor.
The leaded 112 octane Sunoco Supreme is tried first. It was purchased when I was planning on running 12.5 to 1 compression in the big bore. This hash job has 8.9 to 1 comp so the gas has far more than enough octane. Jetting is too rich to start with and it is leaned out until size increases bump up the power only a fraction of an HP. Best power is made with 132's. The 135's make only a fraction of an HP less and they are a safer choice. The curves shown are for the 135's and they are what will be in the bike.
The advance curves are Triumph Twin Performance Stage III, IV, and V. The Stage III is their standard curve modified to work without the throttle position sensor, and Stage IV and V are custom curves they made for me that are 2 and 4 degrees advance from the Stage III. No significant peak torque increases are noted when switching to the more advanced curves. The Stage III is used. It is the safest choice and it is easier on the engine. This curve is the most common one used by tuners on these motors. It is the best curve during our testing using Sunoco Standard, Supreme, and MO2X as well as the special ERC oxygenated gas.
These curves tell me a lot. The peak HP is right up near the red line. This tells me the engine is breathing plenty well for its displacement, compression, and my chosen rpm limit. More cam and bigger valves will hurt rather than help. A compression increase will help boost power throughout the curve. Maybe 5 HP with a boost up to 12.5 to 1. Other than that, the 85 HP this would make is the maximum the motor will go on gasoline with a 8,400 rpm rev limit and carbs. Port and intake tract architecture changes beyond simple porting, and fuel injection are needed to make more. Also, removing the balance shafts and alternator stator.
This motor is using the standard Triumph cast pistons. There ware a lot of dyno runs up past 8,000 rpm. I am sorta taking some risk with these blowing apart at high rpm. Two or three runs at Pendine will be it. Maybe one run if I feel the first one is the best I can do.