Jetting Question

[fsuroxu]

I am helping a friend rebuild his engine (top end). We are getting it bored .080 over with no other mods. My question is, with more cylinder volume, you need more fuel, right? If this is true I need jetting advice to compensate for the bore. Any help will be appreciated.

 

[phragle]

Maybe, maybe not.... the ports on a cylinder work at angles, so when you make a bore bigger, that can change slightly, also you do have slightly more volume, but this does not directly equal a larger jet. if you are drawing more air thru an opening in the same amount of time, you have greater velocity which can possibly draw more fuel thru the jet. go with what you have, but check it.

 

[Whitty21]

well said phragle, just do the job then plug chop it right away

 

[98blaster+4]

dont plug chop it right away. you need to do heat cycles and break it in before you go riunning full throttle runs. do your heat cycles and take it easy for awhile with no sustained high rpms . then you csan do a plug chop after about a tank of gas is run through it.

 

[fsuroxu]

Great advice fellas! You all know your s#@t. Thanks. Rep for everybody, YAY!!!

 

[Whitty21]

haha totally forgot about breakin it in, good advice 98