Milwaukee Eight Big Bore Kits
#11
07-19-2018, 08:57 PM
#12
07-19-2018, 11:06 PM
Tourer
Also FM 117" kit not available at this time they told me, no idea why.
Yeah, what's with that? Their stage kits don't really apply to many of HD's bikes (like my 2018 FatBoy M8 114). And why aren't there more 3rd party high performance entities bringing these stage kits to us? The market for these types of kits not there or what?
Yeah, what's with that? Their stage kits don't really apply to many of HD's bikes (like my 2018 FatBoy M8 114). And why aren't there more 3rd party high performance entities bringing these stage kits to us? The market for these types of kits not there or what?
Last edited by artsbest; 07-19-2018 at 11:07 PM.
#13
07-20-2018, 12:33 AM
Stage II
Milwaukee Eight Big Bore Kits
Lots of big bore kits out there. Currently most of them use the stock HD cylinders that are resized. The Stock 107 cylinder can be safely cut to 4.125" and the CVO 114 and 117 cylinders can be cut to 4.187". Any larger than that and your asking for trouble. Rev performance has there new cylinder that is 4.250" but requires the cases to be re-machined for them to fit and there are some that are putting sleeves in the HD cylinders and IMHO your playing with fire doing that. The 4.250" also has issues sealing the head gaskets so you will need to weld the heads and resurface them. The real issue is the sumping problem that occurs much more often once the engine size increases.
The Revolution Performance 124" big bore kit for the M8 107 does not require case machining, at least according to their website. They are using 4.250 all aluminum NSC plated cylinders. I have no experience with NSC plated aluminum cylinders on a Harley, but would appreciate your opinion.
#14
07-20-2018, 07:33 AM
Also FM 117" kit not available at this time they told me, no idea why.
Yeah, what's with that? Their stage kits don't really apply to many of HD's bikes (like my 2018 FatBoy M8 114). And why aren't there more 3rd party high performance entities bringing these stage kits to us? The market for these types of kits not there or what?
Yeah, what's with that? Their stage kits don't really apply to many of HD's bikes (like my 2018 FatBoy M8 114). And why aren't there more 3rd party high performance entities bringing these stage kits to us? The market for these types of kits not there or what?
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artsbest (07-20-2018)
#16
07-20-2018, 11:21 AM
Tourer
#17
07-20-2018, 11:24 AM
Tourer
The best explanation that I've gotten from Fuel Moto about their big bore kits on the 2018 Softails is that the M8 is very sensitive when it comes to exhaust flow. As of right now, there are no companies producing a suitable exhaust for the '18 Softails that will flow correctly enough for use with a big bore kit. Maybe one of the FM guys will see this thread and chime in for a better explanation.
Then why does their 124 kit on the CVO work efficiently? Is there that much difference in M8 engines?
Then why does their 124 kit on the CVO work efficiently? Is there that much difference in M8 engines?
#18
07-20-2018, 11:40 AM
