santos wrote:This is a question about the power units, and came to my mind again after the last race. Is it possible to rebuild an engine that was already used, replacing only some parts?
Depends on what you are really asking.
As you know, each PU is split up in 6 components:
-Turbo Charger (TC)
- Control Electronics (CE)
As you also know, you can only use 4 of each component, 4 allocations
, during the season before receiving penalties. What you can is mix up allocations of different components. For instance 2d allocation ICE with 4th allocation MGU-K.
However, if specific parts of a component breaks down, I'd like to call these "core parts", turning that component inoperable, you are out of luck and have to replace that allocation with a different one. So unless it's not a core part, you are not allowed to repair it. Things that are not considered a core part, and thus are allowed to be repaired at any time, can be found here;
http://www.f1technical.net/forum/viewto ... 83#p565783
Neither can you remove a working part of a specific component allocation to replace a damaged part of the same component but different allocation. And neither are you allowed to use upgrades as repairs.
Note that as long as you haven't fired up a PU component for the first time during the official time of a race weekend, you are allowed to make changes to it, being either token upgrades, reliability upgrades or simply repairs. But the moment you fire it up during an official sesssion, then from that point on you are not allowed to make any change to the core parts; you are only allowed to swap allocations.