Quote:
Originally Posted by runjmc2
My understanding is the 2.7 is not a bored 2.5, rather it has a longer stroke (3.07in vs. 2.83in). All things being equal the shorter stroke 2.5 would have a lower piston speed (FPS) and allow for a higher red line than the 2.7.
Are all things "not equal" in this comparison, e.g. the design/materials on the crank/etc of the 2.7 better and allow great piston speed than the 2.5.....or is the 2.7 just rated at a higher redline "less conservatively" than the 2.5? Sure this has been covered, just have not come across it.
Question being does the 2.7 really have greater RPM capability over the 2.5 or is it a spec illusion?
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Good questions. Yes, the 2.5 is shorter stroke. But it's a fact that the 2.7 has a higher rev limiter and produces peak power higher. You could, of course, fairly easily tweak the 2.7 with a lower rev limiter and to produce peak power lower down.
God knows if the 2.7 has a better crank, I doubt there are dramatic engineering differences. The difference in peak revs isn't huge anyway.
Neither engine is terribly stressed, if you ask me.