Redstone Engines - Time to warm up?

Hey folks,

I want to build an automatic machine run by a computer. The only problem that is left is that i don't know how long the redstone engine takes to warm up. I've tried different things ,but none is accurate enough. I need the exact time how long the engine need's to change from

- the blue to the green phase

- the green to the yellow phase

- and the yellow phase to the yellow-red phase

Please keep in mind that the time must be in ticks and very accurate.

If someone could somehow find out how many ticks I need in each phase to get to the next. I would be really thankful for that. 

Thanks