Upgrade to an S&S 124 LC Engine

[Die Hard]

I have a S&S 124 LC engine in a 2015 Street Glide with 21,000 miles on it. No issues, no problems, good running engine. I do almost all traveling around the country and I run it pretty hard, especially in higher altitudes like the Rocky Mountains states. The bottom and mid range are strong with the S&S 585 cam, however above that it is lacking in terms of power above 90 MPH. This bike will hit 132 MPH at the redline set at 6100-6200 RPM, however it takes a little while to get there.

I am considering adding an S&S 635 HO cam and getting some Ward headwork to get them to flow better and raise the compression from 10:2 to around 10:8. That would let me keep the dished pistons and not have to replace them.

My question is this, what is my torque curve going to look like with these changes. I don't want to give up what I have on the bottom end, just put more there for mid and top range. The only thing I see that compares somewhat is the dyno sheet from Fuel Moto on a S&S 124 HC engine with the same cam.

[hattitude]

I am considering adding an S&S 635 HO cam and getting some Ward headwork to get them to flow better and raise the compression from 10:2 to around 10:8. That would let me keep the dished pistons and not have to replace them.

My question is this, what is my torque curve going to look like with these changes. I don't want to give up what I have on the bottom end, just put more there for mid and top range.

The only thing I see that compares somewhat is the dyno sheet from Fuel Moto on a S&S 124 HC engine with the same cam.

I have the FuelMoto 124" Outlaw crate engine... they spec out their S&S Outlaw crate engine with gear drive 635 cams, their "Outlaw" valve job on S&S Super Stock castings, and 10.6:1 compression... I had Jaime tune it..

Turned out good with 151 max TQ... here's my sheet.. bike's a lot of fun....

[rigidthumper]

6200 RPM/high gear/late model bagger on the dyno is ~160 MPH, so if you're losing ~30 MPH, there is two things that come to mind-

1) What was your clutch upgrade, and are you using stock gearing? 90 MPH with stock 6th gear is only ~3500 RPM- that should be @/near the torque peak with that engine.

2) Wind resistance is brutal, and the faster you go, the more pressure you have to overcome. (Baggers are about like pushing a 4x6 sheet of plywood sideways down the road, so it consumes a lot of power to do so)

If the lower gears pull as expected, then it has to be the coefficient of drag- and that can be overcome by brute force (and cubic dollars)

[kd]

2)    that's the big one no one considers fully.  Comparing to a sidecar mounted and off will drive it home bigtime. 

[turboprop]

I am surprised the usual arm chair commandos  have have not done multiple deep dives into the differences in wind load between various configurations of bat wings and shark noses. The possibilities are endless, one antenna vs two, full size vs chopped tour pack, etc.

[RTMike]

Star racing uses that cam in there thrasher kits with good results ,talk to George he will be strait with you.

[Nastytls]

I am surprised the usual arm chair commandos  have have not done multiple deep dives into the differences in wind load between various configurations of bat wings and shark noses. The possibilities are endless, one antenna vs two, full size vs chopped tour pack, etc.

For someone that likes to moan about answers that aren't tech related, your post doesn't offer much in the way of a technical answer to the OP.  You also seem to get fairly uptight when people dare to go off topic on your threads, and yet, here we are....

[turboprop]

I am surprised the usual arm chair commandos  have have not done multiple deep dives into the differences in wind load between various configurations of bat wings and shark noses. The possibilities are endless, one antenna vs two, full size vs chopped tour pack, etc.

For someone that likes to moan about answers that aren't tech related, your post doesn't offer much in the way of a technical answer to the OP.  You also seem to get fairly uptight when people dare to go off topic on your threads, and yet, here we are....

I know right? Crazy. But as long as we are talking about wind resistance of baggers, why not. Seems like a subject that has not already been beaten to death and has plenty of room for speculation.

[Hossamania]

 

[1workinman]

I have a S&S 124 LC engine in a 2015 Street Glide with 21,000 miles on it. No issues, no problems, good running engine. I do almost all traveling around the country and I run it pretty hard, especially in higher altitudes like the Rocky Mountains states. The bottom and mid range are strong with the S&S 585 cam, however above that it is lacking in terms of power above 90 MPH. This bike will hit 132 MPH at the redline set at 6100-6200 RPM, however it takes a little while to get there.

I am considering adding an S&S 635 HO cam and getting some Ward headwork to get them to flow better and raise the compression from 10:2 to around 10:8. That would let me keep the dished pistons and not have to replace them.

My question is this, what is my torque curve going to look like with these changes. I don't want to give up what I have on the bottom end, just put more there for mid and top range. The only thing I see that compares somewhat is the dyno sheet from Fuel Moto on a S&S 124 HC engine with the same cam.

I not a fan of the 635 camshaft but I only know how that cam acted in my 143 . A few years ago I saw a dyno sheet of a lc 124 that used the 585 cam and had head work . I think Rick Ward and if I remember it went in the 140s square .  A bump in compression and it really shined . So its your choice but you can use your cam you have now . I can look to find the dyno sheet if you want on here. As far a going max out I going to pass . I just want to cruise on my old bikes

[KiwiRob]

Have you considered the S&S 625 at 11 - 11.2:1. Scary quick in my old Twin Cam 120. - Rob

[Ohio HD]

This setup from Zippers always has had my interest. Using the cams and setting the compression in yours to 11.0:1 with a razer sharp tune would give a lot of get up and go. I have good info from the horses mouth so to speak that they shoot for 10:1 corrected compression.

https://harleytechtalk.com/htt/index.php/topic,94372.msg1091908.html#msg1091908

[No Cents]

  I would suggest the CR630i over the S&S 635HO cams.
I believe Jamie even sells the CR cams nowadays. I'd call him and run your plans by him and see what he thinks.
  I've been running the CR630i cams for years in my 124. I love them. They pull extremely hard off the bottom and deliver super strong power all the way out the back door. Wes did a great job designing this set of cams.

[turboprop]

This setup from Zippers always has had my interest. Using the cams and setting the compression in yours to 11.0:1 with a razer sharp tune would give a lot of get up and go. I have good info from the horses mouth so to speak that they shoot for 10:1 corrected compression.

https://harleytechtalk.com/htt/index.php/topic,94372.msg1091908.html#msg1091908

I have this same engine combo in my blue/white FXR. Definitely not a racer, but a whole bunch of fun. This bike could probably pull a boat trailer up a mountain in fifth gear. Very torquey. If I were to waste money on an engine for my bagger this would probably be it.

[Ohio HD]

This setup from Zippers always has had my interest. Using the cams and setting the compression in yours to 11.0:1 with a razer sharp tune would give a lot of get up and go. I have good info from the horses mouth so to speak that they shoot for 10:1 corrected compression.

https://harleytechtalk.com/htt/index.php/topic,94372.msg1091908.html#msg1091908

I have this same engine combo in my blue/white FXR. Definitely not a racer, but a whole bunch of fun. This bike could probably pull a boat trailer up a mountain in fifth gear. Very torquey. If I were to waste money on an engine for my bagger this would probably be it.

Yeah, he's running a  bagger, so I figure that this is possibly of interest to him.

[838]

  I would suggest the CR630i over the S&S 635HO cams.
I believe Jamie even sells the CR cams nowadays. I'd call him and run your plans by him and see what he thinks.
  I've been running the CR630i cams for years in my 124. I love them. They pull extremely hard off the bottom and deliver super strong power all the way out the back door. Wes did a great job designing this set of cams.

You've made a lot of performance adjustments (cam swaps) to your build. What is it about this setup that keeps you from digging back in there... again

[No Cents]

   this is why.
A lot of fun to be had under this curve.

[attach=0,msg1365172]

[838]

   this is why.
A lot of fun to be had under this curve.

[attach=0,msg1365172]

That's 158/153 in my book... fix your signature!!! Pretty sweet. This cam is on my shirt list for a 124 softail build... might be picking your brain soon... if that's ok??!!👍👍

For the OP... if you can get 10.8:1 you're in prime tr590 zone... would make a great sport touring combo!!!

[Die Hard]

Thanks for the input!

So is it safe to say that if I can achieve 10:8 compression with my existing dished pistons and Ward head work, the results will be the same as flat top pistons with heads configured to them for 10:8? In other words, does it matter how I get there?

[No Cents]

Thanks for the input!

So is it safe to say that if I can achieve 10:8 compression with my existing dished pistons and Ward head work, the results will be the same as flat top pistons with heads configured to them for 10:8? In other words, does it matter how I get there?

   I would ask Rick if he can get your heads set up to hit your desired compression using your dished pistons .

[CVOKing]

I think you would be amazed at what would happen if ya did good headwork and bumped cr and left the 585 in it

[Die Hard]

Funny you say that CVO King. Jim at Mega Flo said the same thing.

[Barrett]

Ask your porter about the 1.725 rockers for .621 lift.

[Tireman]

Funny you say that CVO King. Jim at Mega Flo said the same thing.

Just curious Have you decided on who will be doing your heads Ward or MegaFlo? Can't go wrong either way!

[C-Cat]

I like the idea of moderate compression S&S 640 cams in a124 over 585's. 145+ HP and TQ on tap with good heads (Megaflo) quiet valve train and plenty of extra power over the 585's. Or for more seat of the pants earlier TQ TMan 662-2 or CR cams like No Cents and tapping that 124's potential.