GM's new V-8, codenamed Ultra, could replace Northstar
By Todd Lassa
General Motors is at work on a new overhead-cam V-8 that could be a replacement for its costly Northstar V-8 (at right). The General is mum on the engine, codenamed Ultra, which we expect to make its debut no earlier than 2009. That would make it a good candidate for the next-gen Cadillac STS V-8.
Given the secrecy surrounding the Ultra V-8, there's no word yet on displacement ranges. But as the Northstar, a physically big and costly engine, can go only to 5.3 liters-and that's with siamesed liners-logic suggests 5.0 liters would be an ideal starting point. GM needs the engine to be able to go out to as much as 6.0 liters to enable Cadillac to compete with the new generation of big-bore V-8s from Mercedes-Benz.
Two things we do know about the Ultra V-8: It'll feature GM's latest and best technology (variable valve timing for intake and exhaust, as used in the high-feature V-6s, is a good bet) and with most of its four- and six-cylinder and diesel engine work accomplished, GM Powertrain can concentrate a lot of resource on developing the Ultra over the next few years.