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■ Rocket 3 TFC engine is a completely new block & head etc.
■ Rocket TFC is indeed a 2.5L according to the tour guide (no info known on exact cc, or anything else), but I could see the engine is in fact noticeably slimmer than the outgoing 2.3L
I spotted some cylinder heads in a large cardboard box so sneaked off tour line like a bold boy, they were rather large ones which I thought initially were Rocket III heads, but then realised they were way too slim/narrow, and possibly longer,,,
They were tagged "Y Series Cylinder Heads. I didn't know what they were from. But later on it became apparent they were Rocket 3 TFC heads.
■ Rocket 3 TFC upper crankcase sleeve bores are around 2cm wider than originals - this is purely a guess as I had no way of measuring other than I know I can just about fit my fist into the sleeve bores in the old 2.3L crankcase, and in the 2.5L my fist was falling around.
Now the sleeves could of course be thicker than the old ones, and bore still 101.6mm, and it's a longer stroke that gives the 2.5L, I don't know, but the bores sure do "look" a lot bigger.
So the new Rocket engine is stronger more powerful and larger displacement but much much leaner/trimmer on the outside
■ There were 30 mated pairs of Rocket 3 TFC engine crankcases there on trolleys.
■ The Rocket 3 TFC upper crankcase part number is 1168822
■ There was a red over grey primer painted original 2.3L upper crankcase near the TFC cases, but with no serial number on it