Maximum Bore for 107" Cylinders

[Ohio HD]

Just came across this online, boring the factory 107" cylinders to make a 118" motor. Does that sound feasible, or is that like getting the Twin Cam factory cylinders bored to 107" and kinda thin?


http://headhoggersllc.com/hh-118-milwaukee-8-kit/

[rigidthumper]

I've heard the SE 114 cylinders can be safely bored bigger than the 4.075", 114" CVO cylinders too because they have more liner. These guys offer 4.145" piston, 118".  Suburban offers 4.185" pistons, which is 120". I guess we'll see who lasts 

[Ohio HD]

I didn't know about the 120" from Suburban. This must relational then like 88" to 103" cylinder castings.

[rigidthumper]

Just got a note that says 107 M8 cyl measures 4.272 +/- .003, stability becomes a factor once past 4.125". Do as you feel comfortable.

[Ohio HD]

         NO!   

[TorQuePimp]

Just got a note that says 107 M8 cyl measures 4.272 +/- .003, stability becomes a factor once past 4.125". Do as you feel comfortable.

@.0735 thick plenty safe

Bigger than that is pushing it

Confirmed by a number of shops

[Hillside Motorcycle]

Just came across this online, boring the factory 107" cylinders to make a 118" motor. Does that sound feasible, or is that like getting the Twin Cam factory cylinders bored to 107" and kinda thin?


http://headhoggersllc.com/hh-118-milwaukee-8-kit/

117" safely.

[HD/Wrench]

Just came across this online, boring the factory 107" cylinders to make a 118" motor. Does that sound feasible, or is that like getting the Twin Cam factory cylinders bored to 107" and kinda thin?


http://headhoggersllc.com/hh-118-milwaukee-8-kit/

Jim did a fair amount of testing on the piston along with the dome shape working with swirl along with combustion chamber shape. From a data stand point he did his home work .  Nice item for sure .  as for the max bore  I doubt any shop can tell you much at this point. Would have do run several of them and see how it turns out . Good old fashion testing in a long term data logging experiment .