Friday, November 20, 2009

Before They Were Beaters: 1981 Cadillac 8-6-4

As opposed to the '81 Diesel
Cadillac that used the 8-6-5-7-2-1-0-1-0 deactivation sequence utilizing the latest in bottom end failure technology, the 8-6-4 system used hydraulic actuators to close off either 2 or 4 of the intake valves and reduce fuel input from the TBI system in low-load situations. Offered only for the '81 model year, this system caused GM so much trouble that it was discontinued for all sedans after the first model year and limousines after '82. Even when all 8 were working in unison, only 140hp was produced out of 6.0 liters.

The remedy for this disaster was the equally dreaded 4100 "High Technology" V8, which offered new space age features like automatic coolant/oil homogenization, permanent cylinder deactivation, and self actuating rotating assembly ventilation.

1 comment:

  1. Hat tip to Dave, who corrected me on the style of cylinder deactivation that Caddy used. It would be pretty difficult to to cylinder deactivation with TBi and without valve actuators!