The Re-build

Triumph Build

Few months later the forged pistons and Carrillo forged rods arrived from the states. Also I added to the mix was Hayabusa injectors as the standard ones had a flat spot in middle rpm range. Lack of fuel I think. The first new lesson was understanding what bolt stretch was all about in relation to torque. This info came with the Carrillo Rods and bolts. Once higher loads are placed on a engine these factors become critical. See following link if interested. https://www.enginelabs.com/engine-tech/blueprint-series-measuring-rod-bolt-stretch-vs-torque-with-arp/. 

Once the Rods were installed, the bolts were longer than original and were catching  the balance shaft on rotation. So a corner was removed off the bolt giving 20 thou clearance. The forged pistons also drop the compression ration from standard 11:1 to 9:1 which allows a bigger charge in the compression chamber. Along with the new injectors we can produce more power with less stress. The new ignition map changed the spark timing from 5 degrees before TDC (top dead centre) , to 5 degrees after TDC. This takes some major stress off the con-rods and crankshaft. I also measured all the big end bearings which were still within tolerance. Tricky thing to remember when reassembling these engines the crankshaft only lines up with timing chain I think its every 9 rotations so lesson learnt.