PDA

View Full Version : Compression Help Please!!!!


MXRACER86
12-02-2004, 08:51 PM
I have a 2005 Z-400. Can I run 12:5:1 compression with pump gas?
AdvantageCycle
12-02-2004, 10:21 PM
NO, that would require race gas, I would recommend 104 octane for that comp ratio
TC426EX
12-02-2004, 10:34 PM
Definitely not man... 11:1 is the absolute maximum compression for running pump gas... If youre 12 or 12.5 you will definitely need race gas....
LazeR
12-02-2004, 10:48 PM
also you would probably have to have a stronger rod.
F-16Guy
12-03-2004, 08:54 AM
Originally posted by TC426EX
Definitely not man... 11:1 is the absolute maximum compression for running pump gas... If youre 12 or 12.5 you will definitely need race gas....
Not true. A Z-400 will handle higher compression because it is water cooled and has a shorter stroke. Detonation is affected largely by heat. Since the 400ex is air cooled and has one of the highest friction valve trains known to man, it runs hot anyway. Then bore it out and start raising the compression, and it runs really hot. That's why you can't go much over 11:1 on a 400ex. The Z-400 already has 11.3:1 CR in stock form; I don't think going up one point will give any problems with pump gas.
MXRACER86
12-03-2004, 09:56 AM
Thanks guys for the replies.......... anybody else??????