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Engine Mechanical TopicsDiscussion for motor builds, cams, head work, stripped bolts and other engine related issues. The good and the bad. If it goes round and around or up and down, post it here.
Max, I don't think that is what the OP is saying. He bought a 110 engine to install in his 2001 Road King. IIRC, the first factory 110 was in the '07 CVO Dyna? I don't know the details of fitment or whether or not there must be modifications made but that's another kettle of fish and a subject for another thread but I would think it will fit without a lot of modifications.
I know the combustion chambers on the 110 were much bigger than the 88/96; 95-98cc IIRC which will require a set of domed pistons but I think 12.5cc domes might push the compression envelope.
Max, I don't think that is what the OP is saying. He bought a 110 engine to install in his 2001 Road King. IIRC, the first factory 110 was in the '07 CVO Dyna? I don't know the details of fitment or whether or not there must be modifications made but that's another kettle of fish and a subject for another thread but I would think it will fit without a lot of modifications.
I know the combustion chambers on the 110 were much bigger than the 88/96; 95-98cc IIRC which will require a set of domed pistons but I think 12.5cc domes might push the compression envelope.
If it's a complete motor, it won't fit unless it includes later tranny and primary.
It's not a kit, I bought a used 110 out of a 2013 Road king CVO. So from what I'm grasping from y'all is, my 5 speed won't bolt up, my primary won't work either, and the 12.5cc pistons are too much? On the pistons, s&s specs are saying their 12.5cc pistons are 10.6:1....my goal is 10.5:1 roughly.
Last edited by Prospect1986; Oct 10, 2025 at 06:14 AM.
Reason: Left out info
Mine is in a 2012 CVO RG. Really woke the bike up. Max torque at around 3500 and carries a flat torque curve till redline. I like bottom end torque. I don't live in the high rpms. I'm usually 2 up and we ride in eastern Ohio Western PA and WV. Lots of hills to climb. I like the 110 engine. I could go 114 easily. Maybe once we get a new bike in a couple years.
ETA; found my Dyno sheet. 111hp/120tq. Stock pistons. All headwork intake injectors and cams.
Very nice! I like those numbers you're putting out! 😁
It's not a kit, I bought a used 110 out of a 2013 Road king CVO. So from what I'm grasping from y'all is, my 5 speed won't bolt up, my primary won't work either, and the 12.5cc pistons are too much? On the pistons, s&s specs are saying their 12.5cc pistons are 10.6:1....my goal is 10.5:1 roughly.
A number of things changed between the 5 speed motors and 6. It's easier to replace the whole thing..
IMO a motor of that size with 10.5 to 1 and the 585 cam is fine. WFO Larry likes to run the 585 at 11 to 1.
It's not a kit, I bought a used 110 out of a 2013 Road king CVO. So from what I'm grasping from y'all is, my 5 speed won't bolt up, my primary won't work either, and the 12.5cc pistons are too much? On the pistons, s&s specs are saying their 12.5cc pistons are 10.6:1....my goal is 10.5:1 roughly.
Max is right; easier to replace motor with six speed than try to modify to work with the five speed. The '07 up 110s hooked up to a six speed via a different primary. As for the pistons, it really doesn't matter what the vendor says about compression. Use a compression calculator like the one on the BigBoyz website, plug in the data and see what comes out. You could run the 12.5cc dome pistons but CR would be about 11:1 which, IMHO, is aggressive but if WFO Larry likes it, why not.
Thank you to everyone for the advice, tips, and opinions...I believe I'm set now, I'd much rather have the 6 speed tranny anyway. And I sent an email to Hillside, they seem to be the guys to talk to in order to get everything smoothed out with my build. Again, I greatly appreciate everyone!
JMO dual plugs yielded limited gains on a hemi head shovel
I expect it will be even less on a T/C with a much flatter combustion chamber
I do agree, it's not much of a gain in power, it's more so that I get a more thorough cleaner combustion. It only costs $125-150 per head to have it done, so I figure it's worth the $ to ensure no fuel is wasted? But, maybe I'm wrong...that's one topic I'll be discussing with Hillside as well, to see if there's any real benefit to it, not necessarily for any extra gain in power. Thank you for the input. 👍
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