GP Customs inc. Tech
	I)Cylinder heads: So lets talk a little about cylinder heads                                 and how they work and why!!!!!              *Its important to understand that the volume                  of fuel vapor and shape of the head when                  in proximity of the piston can be a very....                  good thing or bad with regards to                                                    performance. It is therefore worth a basic                  understanding of what not to do even if you                  only have a basic understanding..........                  ...Understand???!!!!??%$&*(%#  No?               *Ok well remember when you were told that                 higher compression was good? Well the truth                 is that with high compression comes higher                 dome temps/detonation and pre-ignition.                 What you need is a good combination of squish                 and volume.         A)Squish: The area surrounding the combustion                             chamber where things get rather close                             between the head and piston.               * Ok so why a squish area?...Well there are a                   few good resons.                           1)move the mixture into the combustion                               chamber.                           2)reduce the ability of flame spread onto                               outside of the piston and reduce                               compression temps.               * But alas with the squish doing a temp and                   combustion control job there is the loss of                   unburned potential power lost in the outside                   charge that resists burning. Best settings for                            (91-99) machines seems to be 7.5-7.9cc.                    Squish should be set .026 to .028 of an inch.           B)Combustion Chamber: Yes its the area                                          surrounded by the squish band!!!! This pocket               does most of the real work and depending on               bike you own it could employ anything from               a hat-section,conical to a torus-type chamber                          etc...         C)Plugs :Plug position in the combustion chamber               is also a very important item to monitor as               the goal again is not to screw with the                                           combustion. So you keep it as close to the roof               of the chamber as possible. The more it                                        protrudes the more inefficient the flame spread              across the pistons dome.             * Read plug for timming by the burn pattern on                          the electrode tip. 3/4 to 7/8 from tip to plug will               be silver in color for correct ignition.   See tuning log for a useful item for reading plugs
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