Why is it like this?

[yellow400ex05]

Why does the 400ex have such a low stock compression ratio compared to the z400?

stock 400ex compression ratio: 9:1:1

stock z400 compression ratio is 11:3:1

how come the 400ex's is so much lower?

and How can the z400 run on 89 octane i guess detuning it to make it compatible with 89 octane?

[zrpilot]

There is a difference in static vs. dynamic compression. Cam profile and timing would come into play. I'll bet this is part of the reason.

[yellow400ex05]

anyone got anymore info on this I'd love to learn another new thing!

[yellow400ex05]

anyone?

[JOEX]

I belive water cooling has an effect on the ability to run lower octane fuel.

[Aceman]

Originally posted by JOEX
I belive water cooling has an effect on the ability to run lower octane fuel.

Yep.:)