Please forgive me if my next words are a bit strong, but I feel strongly about what I'm about to say.
May I respectfully suggest that you have no business taking apart any major Prius component such as the engine, power split device and/or other parts of the drive train, computer(s), MFD, or battery components unless you have the shop manual(s), and you refer to them often? Having the shop manuals would allow you to answer your question quickly, easily, and accurately.
If you want to work on your own car, that's admirable! But please help yourself as much as possible by investing in the best documentation available, no matter how much it costs!
Personally, I'd
never ever attempt serious surgery on any of my vehicles unless I had said manual in my possession and opened up on the workbench.
EDIT: Oh, I just realized that your question may have been just one of curiosity, and that you may have been joking about taking the engine apart. If so, my apologies! Umm..and I don't know the answer to your question, either. I'll just go be embarrassed and sit in the corner and shut up now...
