New bullet for CSX3170

[Cobra #3170]

I lost a roller lifter (axle broke) at the Laguna Seca 50th anniversary Cobra event last year and the rebuild was just completed at Kinetics Racing Engines in Michigan. The new engine has more compression, a cam with more high lift duration, lighter pistons, a much lighter crank, and increased head flow. My goal was to increase top end horsepower and decrease low end torque to help control wheel spin.

Excuse Section: The temperature and humidity in Michigan have been horrendous this past week so my dyno numbers were not what I had hoped for. Although there is an SAE correction factor it seems to project worse numbers when conditions are bad and optimistic numbers when the factors are negative (cold air and good barometric pressure).

To put things in perspective Kinetics recently dynoed a Robert Yates Cup engine that was 850 hp at Yates Shop, the Kinetics dyno showed 805 hp with a peak torque of 566 lb/ft. This was done under much better conditions than we had yesterday. Our inlet air temperature was 89 degrees F with a vapor pressure of .92 . 3170's new bullet made 827 hp @7500 with a peak torque of 642 lb/ft at 5500. Average horsepower from 5500 to 8000 was 764 and average torque was 598 lb/ft from 5500 to 8000, not too bad for a normally aspirated 1950's truck engine. Kinetics estimated that the engine would have a corrected number of around 850 hp under conditions closer to a 0 correction factor.

Next step, install it in the car and put the race suspension back on, should be running sometime in August.