Port before or after bore?

[2hundredx]

Yeah I am wondering if I should bore my cylinder to my new piston before i have the port work done or after? Which should come first? Thanks, collin

[shortline10]

Same time so you dont have to rejet the carb twice LOL .

[nd4speed]

Boring the cylinder changes port timing so I would think- after bore.

[tri again]

4 stroke?
I'd be tempted to polish the ports after the bore because it may leave some sharp new edges.

They can glow and cause pre ignition ping etc.

May have no real basis in reality since I've never seen a fresh bore on
whatever it is (what type engine) you're working on.
If it's a 2 stroke, there may be some secret formulae for square area of the ports vs bore and stroke and opening them up, even to polish, may be the exact wrong thing to do.

Someone on here definitely knows.

[nstyle73]

When I contacted Flowtek about porting, Denny said that they prefer to port before a bore job, but can be done before or after. This statement was made regarding a 2-stroke.

[MTS]

Always See it after the bore and before the finish hone..Myself.

[Bryan Raffa]

as long as the ports are champherd after the bore,,it dont matter if its before or after..