2004 to 2020 Mazda 3 Forum and Mazdaspeed 3 Forums banner

1 - 5 of 5 Posts

·
Registered
Joined
·
3 Posts
Discussion Starter #1
Hi All,

Not sure if this should go in the Engine and Performance forum but it didn't seem to fit there.

I'm wondering if anyone knows how the compression reduction from 14:1 to 13:1 (CX-5) to 12:1 (Mazda3) is actually achieved? Is there something physically different with the engine like shorter piston rods or is it a timing thing that is controlled electronically?

Just interested to find out what the actual difference between the engines is.

Thanks,
 

·
Registered
Joined
·
570 Posts
Compression ratio is the ratio between the volume of the cylinder with the piston at bottom dead center to the piston at top dead center. Has nothing to do with timing or external factors. It's likely that either a different (less domed) piston, or a larger combustion chamber in the cylinder head gives the lower ratio.
 

·
Registered
Joined
·
3 Posts
Discussion Starter #3
Thanks outtaLuck. That's helpful.

I wish there was more information, drawings, etc. out there on this engine but I guess that will come in time. I'm just used to being able to find whatever I wanted on my old FS engine.
 
1 - 5 of 5 Posts
Top