Bigger bore motor for my Triglide

[bluerim]

I have a stage two build (all bolt on ) in my 2017 Triglide. We ride two up pulling a time out camper trailer.  What I found after a trip to Sturgis this year was that I still wanted more power.  Most of my riding does not get over 3200 rpm.  This is at 75 mph. Keeping up with interstate traffic at 75 mph was working the motor pretty hard. It ran nice with no overheating issues but was pretty much maxed out at 75 mph pulling the camper. It kept up with traffic but started to loose a little when I had a headwind or a hill.  I downshifted for the hill but found the rpm in 5th too high for flat stretches against the wind.   A little more power would be nice so I want a 117 or 120 kit to get more TQ at under 3000 rpm.
What is the best way down low cam  available for 117-120 cu in motor.  I don't like the high cr in the kits available. Is there a piston cylinder kit available yet for heavy weight pulling like mine ?   The camper weights 385 pounds empty with another maybe 100 gear, plus two up riding 300 lbs for both of us plus another 60 lbs gear on the trike.

[Geezer_Glider]

Yikes! You need a truck not a Harley. All kidding aside I would worry about the klunk drive 6 speed holding up to that situation. Especially if you add more power. More displacement is the correct way to go in my opinion your on the right track. I would think you could cut down the forged pistons to lower compression, just have to check. Thought I saw someone was offering a dished piston now. Anyway you go you will probably have to rev it a bit to get that much weight, rolling resistance and air resistance going.
Just saying,
R Meyer

[rigidthumper]

Have your stock cylinders bored/fit to 4.125 pistons. Combine with the TTS 200 cam, AC, slip-ons, & tune, should be over 100# of torque from 1800 RPM to 5800 RPM. Should be enough to properly motor through the hills

[bluerim]

Is the TTS 200 cam for bigger motors.  I had a TTS 100 in my 103. 
Each time I make a change to my Trike, I need a trike dyno to tune for the changes. That cost is about $700 Canadian.  Too much to keep trying something different. Not to mention there are no trike dynos  anywhere nearby.  So, someone mentioned the (expensive) Thundermax tuner as it will self tune for any changes I make.
Anyone that can chime in here would be appreciated.

[rigidthumper]

M8 100 cam is designed for stock 10.5 compression, 107".
M8 150 is the midrange 10.5 cam, 107-114.
M8 200 is the 11:1/larger displacement cam 117-120".

[bluerim]

Is the TTS  200 cam and high compression good for a heavy weight application ? Trike and camper trailer.  Should the CR be less.  Someone said trikes don't like over 10.2:1.

[rigidthumper]

Difficult to find low compression M8 pistons at the moment, so adapt with slightly more cam. 4 spark plug 4 valve heads should be more tolerant of higher compression with a good tune.

[bluerim]

OK thanks.   I will watch torque curves using different M8 builds as the summer progresses.  Maybe a winter project.

[bluerim]

Looking at Fuel Moto's dyno chart for the 117 M8 motor 123.7hp, 134 tq.   and recalculating for a probable trike dyno loss of 16% it works out to about 107hp, 115tq.   Now considering my 107 stage 2 motor Trike dyno'd at 97.23hp, 100.15tq. It is a substantial bump in power. I am looking for torque mostly. The 117 kit looks like it makes about 100 tq (trike dyno) at 2000 rpm. My 107 looks like it would be about 80 tq.  Much more "grunt" starting off.  So if the trike likes the 11:1 CR I should be OK.  It is starting to look like that's the way I will go. Or maybe I will wait and see how reliable the 120 kits are.
Thanks for the input guys

[thumper 823]

The VE of any IC engine is pretty hard to change with any cam @ around 3000 RPM.
To up your TQ/Hp figures, you will have to up the SQ.
Personally, i would op for a high RPM  engine that will deliver.

[Matt C]

More cubes never hurts.

[TrikeRider]

I guess you know this but your warranty is gone.