The Panoz Esperante uses Ford SVT Cobra motors.
Quote from article:
Future changes will keep up with Ford developments, including an upcoming three-valve version of the four-cam engine. Panoz notes his chassis will accept the bulkier 5.4-liter engine when it becomes available. "And if Ford ever puts the V10 into production, I can easily adapt my engine-bay module for it."
Link to full article:
http://www.autoweek.com/article.cms?articleId=100500
This seems to suggest a 5.4-liter, 3-valve, four-cam engine.
Quote from article:
Future changes will keep up with Ford developments, including an upcoming three-valve version of the four-cam engine. Panoz notes his chassis will accept the bulkier 5.4-liter engine when it becomes available. "And if Ford ever puts the V10 into production, I can easily adapt my engine-bay module for it."
Link to full article:
http://www.autoweek.com/article.cms?articleId=100500
This seems to suggest a 5.4-liter, 3-valve, four-cam engine.