I have a 2010 Street glide that was originally a 96. In 2011 I had harley install their 103 stage IV kit and paid $150 extra for their MVR 110+ polished and ported heads to replaced what came with the kit which the manager got in trouble for. In 2014 I had a 117 built using Revperf pistons and cylinders, woods cams, and I kept the screaming eagle heads. Now Im rebuilding the 117 motor because the 5 piece S&S crank I had installed when i built the first 117 broke. I was told it may have happened because i didnt have a timken bearing. The crank arms were sort of scissoring and were really wobbly when we took the top end off which caused the front pistons to wear away the front of the front cylinder and the rear piston to wear away the rear of the rear cylinder. I called revperf and gave them the measurements of the cylinder walls and was told its time for new ones because it was way to wide for their tolerances. Then i decided to look at my clutch and saw my stock clutch basket had 2 cracks in it on different parts. That was a disaster waiting to happen. And for ***** and giggles I looked at the starter which had 2 teeth missing and one about to crack. So now Im trying to make this build almost bullet proof and not cheap out like i did last time. Good thing my buddy sells this stuff and gave me everything at cost. So my question is this. I have a 58mm screamin eagle throttle body on it now from the 103 stage 4 kit. Is a 58mm throttle body enough for a 117 motor with what i have or would it breath better if I got something bigger. I saw S&S has a 66mm throttle body. Is that overkill or should I go with something bigger than a 58mm but smaller than a 66mm?

Screamin Eagle MVR 110+ polished and ported heads (used these when I went from a 96 to a 103 in 2011 with the screamin eagle 103 stage 4 kit)
S&S 117 piston and cylinders
S&S 3 piece crank
S&S TC3 Cam plate
S&S TC3 Oil pump
S&S forged rocker roller arms from 8620 steel
S&S quickie adjustable pushrods kit
S&S Premium high performance hydraulic tappets (replaced woods knight prowler tappets)
Evolution Industries diamond clutch basket (upgraded over their regular unit)
Woods TW-9-6 cams with .580 lift (already had those when the 117 was built replacing the Woods 888 in the 103 which are now in my dyna 107)
Spyke Starter (says 46% more cranking torque than stock)
Screamin eagle high flow injectors replacing the ones from stage IV kit
Delkron Billet rocker arm supports
Timken bearing
Upgraded bearing on the other side of the timken bearing
Bassani Road rage 2 with high output muffler replacing D&D exhaust

 

I went with the HPI 62-64 mm throttle body on my 124 setup . was tossing the 58, 62-64 - 66mm throttle hog from s&s around for some time. after talking with jimmy from HPI I went with there 62-64mm. from prior experience the HPI 58 with out flow the screaming eagle 58 and made more hp/tq hands down. jimmy stated that they had done a lot of testing between there 62-64 and the 66 throttle hog and that there 62 would make more power and tq through out the whole power band. and after getting prices on both throttle bodies the HPI unit cost me less.I have talked to several shops that due big builds on what size they recommended and they all like and use the HPI 62 setup.

 

You might get more responses in the Touring Forum and/or the Engine Mechanical Topics Forum than the Rushmore Forum.

 

I have stock re-worked heads and the 50mm TB on my 124 right now. Eventually I might do the heads again and upgrade the TB. I'm curious as to the difference between the S&S 66mm and the HPI 62-64mm; I'll have to look into it more.

 

the 66mm has a huge plenium and when the throttle blade opens it a big gulp of air going in and actually slows the velocity down creating less cylinder fill vs the 62-64 hpi unit. on the testing hpi has done on back to back comprehensions on 124 motors and has proven the 62 out performs the other and has a much better throttle response too.