Well seems natural progression has Jaime splitting cases and balancing cranks, next up should be a FM 120. Jaime, any input here? I have your 107 in my Dyna and a HQ 107 in my Ultra, would like a 120 in my Ultra .

 

Have to say 120" or plus almost perfect bagger power!

 

If you are splitting the cases anyhow it makes sense to stroke it and put in a stronger crank.

 

Subscribed, this ought to be interesting.

 

It would be nice to see a vendor take the HD120R, CNC the heads, cams and sell that as a nice package. I bet there is some power to be found in that engine.

 

But money wise, true and weld and 107 is about 1700 bucks. add 600 for heads. Which to me, is outstanding bang-for-buck results.

king, are there dyno sheets available for stroked motors? for example, the numbers the 107 can put out are solid. 107, true/weld, heads = 110/120ish.

how about a 113? or 117? and at what point do you have to start upgrading everything else in the drivetrain (belt to chain conversion, clutch, tranny, etc)

 

The longer the stroke, the higher the piston speeds, the faster the wear in theory.

Big Bore 'square' motors forever!

 

The 107 is unbeatable BFYB. Hands down.

I have seen some 124" & 120" sheets at about 130/130, very good ones run closer to 140/140. Most dynos are +-15% anyhow.

The issue I have with truing and welding is that your crank becomes a disposable item. I am old fashioned but a proper crank should last basically forever. Press it apart, change bearings, go again.

As for drivetrain there are lots of 124", 120" and 131" running stock drivetrain and belt. My driveline is stock apart from the SE clutch spring. The 09 up clutch and box are pretty bulletproof, I havent heard of a single box failure. They blow seals, but they do that stock.

 

good to know king thanks.

 

Since when did Jamie start balancing cranks.He said he trues them not balances them.You would think if your willing to take the time to split the cases and weld and true the crank,you would take the time to balance it too,but everybody has they're own way of doing things I guess.