Keith, FWIW, I use a 24" long 1/2" drive socket extension to bring the breaker bar outside the car fender and I use a 4 feet cheater pipe over my breaker bar which is supported at the fulcrum by a large (5-6 ton) jack stand. I use a large jack stand because a small 2-3 ton stand is not tall enough. Anyway, a socket extension will twist like a torsion bar but in the end it breaks loose the crank bolt for me every time. Stacked extensions will also work but have a bit more total twist. The most recent timing belt I did was about 3 weeks ago on a 2002 Honda Accord 4 cyl.
The support given by the jack stand is important. It reduces the give as you pull down on the breaker bar/pipe and keeps the socket square on the bolt head.
Give it a shot next time.