Get Up and Try Again
Even though our backfire condition was the result of a wiped cam there was a bit of relief in positively identifying the problem. Fortunately, we knew that all other systems were operating perfectly for breaking-in the replacement cam. At least until the modified Duraspark began giving us trouble. We pulled it and tossed in a MotorCraft dual-point for break-in.

Comp Cams techs suggested that perhaps the cam failure was due to too much spring pressure. They suggested this time around we adjust the valvetrain to zero lash, just for the break-in. The more laborious option would be to use light pressure break-in valve springs. Our second attempt was successful and during the process we reached no more than 200 degrees in water temperature and the 460 idled down nicely upon completion. A few consecutive days of hour long variable speed driving on open backroads set our rings and loosened up the motor. Just prior to scheduling our dyno session a poorly routed transmission line caught fire after our first good burnout. If you recall we originally picked up our low mileage bottom end from a fire damaged motor home. Fortunately, we avoided a painfully ironic and premature ending to our StreetWise 460. We made up some steel lines and re-adjusted our idle and looked forward to our dyno session.

Dyno Testing
On this day we had two objectives in mind. To not only baseline the 460, but to also test out a D.U.I 460 distributor against the dual-point MotorCraft unit. We'll detail the comparison in an upcoming aritcle. The best pull of the day came, as expected, with the high-power D.U.I. ignition in place. The 460 laid down 358 horsepower at 5000 rpm and 387 ft.lbs. of torque at 4500 rpm.

Conclusion
While those results are nothing to sneeze at they do seem short of our expectations. We believe the rebuilt C6 transmission might be slipping in drive, thus holding back power to the wheels. To make matters worse, the 100-plus degree summer heat of central California gave us no motivation to press on with troubleshooting on the dyno. We've got the project car back at the shop and will investigte the C6 tranny for slippage. Look for some revised numbers in an upcoming project car update.