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runjmc2 · 05-01-2013, 01:54 PM

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?

05-01-2013, 01:54 PM	#5
runjmc2 Registered User Join Date: Jan 2013 Location: Phoenix, AZ Posts: 231	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?