S&S 128 Big Bore / Harley-Davidson Lowrider S

I built my own S&S 128 Big Bore Stage IV upgrade for my 2020 Lowrider S. I took my time, spending an average of two to three hours per day over a period of four days, then three days for heat cycling and finally two days for dyno tuning. The overall experience was rewarding. Now, just need a little more snow to melt!
All of my parts were sourced from Fuel Motto in Appleton Wisconsin through my local dealer House of Harley-Davidson in Anchorage Alaska 
Thanks for watching 😎 

[@garychristenson3894]

Very interesting video. Lots to learn. Your dedication is admirable, and way to unlock every ounce of hidden potential! Live good, ride hard, and be safe.

[@robb907]

Thank bro 💀!

[@chrissmith7669]

Great numbers. Gives me lots to consider

[@tommiller8714]

Darn good peak HP/TQ numbers (141/150) and nice curves. Lucas at Fuel Moto gave you a great revised Map, from which your Tuner tweaked upon, fine tuned. Impressed; great project! Ride safe. Tom M., So. Cal., '21RGS & '22FXLRS

[@robb907]

Just got home from first ride. Very happy! Thanks for taking the time. Nice rides, my other bike is 2020 FLHXSE w/ SE 131

[@tommiller8714]

@@robb907 That's cool. Best of both worlds with Harleys; 1 Touring chassis bike (w/131...awesome) & 1 Softail sport bike. I'm still at Stage-1 on my RGS, torque cam soon. My last built bike was a '20SGS w/SE Stage-4 117. Leaning toward eventually doing a T-Man 130" Kit on the '21RGS.

[@robb907]

@@tommiller8714 that’s gonna be sick man! I ordered a Brocks performance swingarm for my SG. Won’t have it until the end of May though. Let me know how you’re T-man kit works out!

[@NormalSoMDStuff]

Wow great job man..sounds great!

[@TheCuttz1984]

That sounds mean. Love the build ❤

[@mikegray2445]

That dip you were seeing is a characteristic of the 2-1 exhaust.

[@robb907]

I used to think that also however I’ve seen it with some two into twos’ as well. Additionally it can be an artifact of the auto tune feature on the handheld. I’m just happy we were able to tune it out

[@benb7102]

It’s the short 2-1 and most 2-2 that has dip. A good full length 2-1 will not have the dip

[@johnbeardsley7360]

wow those cylinders are huge

[@nbowling10trio]

Awesome build. Be nice to see how much difference octane changes output. Like shell power 93 vs Marathon 94 vs Sunoco 92. I'm always hunting for ethanol free myself. Consistent fuel is key for consistent tune. I can tell a difference in the way the vrod runs different on power compared to Sunoco premium. Sunoco seems to run better

[@robb907]

@@nbowling10trio unfortunately we have the worst fuel in America up here. 90 octane max. Chevron is the best we can get up here in my opinion, but still 90 octane.

[@thakery5720]

I have found through trial and error, that Cometic gaskets can be used multiple times - just as long as the Viton rubber coatings are there and not torn..... when we dyno'd my twin cam with S&S640's and Ultima increased ratio rockers (so total lift is 0.660") with the old S&S taper mufflers, we had to step out of the dyno room after about 20 minutes because we had thumping headaches despite using ear defenders..... my neighbours love me !

[@robb907]

Hahaha nice!!

[@spoom937]

Great video man! Congrats on your 1st successful Harley build!!! Much love from Ohio!

[@robb907]

Time to ride!

[@20sgcvo90]

Lucas at FM is also helping me iron out my FM 128 he’s great 👍🏼

[@robb907]

Yeah man! I also have a 2020 CVO black stardust fade. I have a 131 in mine. What color you got?

[@20sgcvo90]

@@robb907 sand dune

[@SQUID_Road_Glide]

You're a better man than me. I was told with my level of knowledge I could put a 124 on my bike. But I'm chicken-$h!t. I know I would have gotten lost. You have snow but you also have stunning venues. 2FD brother. SQUID ET1(SS/SW/MTS) US Navy, Ret.

[@robb907]

Actually, it wasn’t that bad. It was 1/4 of the job that a 350 Chevy rebuild is. It was a lot of fun. Thank you for your service to our country brother! 🇺🇸

[@SQUID_Road_Glide]

@@robb907just watched it again. My initial thought on the DYNO dip, is the shorty pipe phenomenon. I want to change my TRASK pipe to that Jackpot your rock'n. TRASK is a drag race set up. But I'm glad to see I was wrong about the dip. I suspect your Hpi gave the mail-in tunner the ability to tweek the air/fuel erasing the dip. I run a TRASK Shorty on my Fat Boy, and I have that dip. My bike doesn't like hold 35mph...that's the dip. I got a SE 64mm with 5.5 injectors. OBTW, you were right the first time, the smoothness in your DYNO line compared to your buddy is the more favorable over any gains of 1-3 Hp and/or Tq at those levels. The only other thing one would desire is a flatter line. I hope my line is as smooth as yours. Do you verify you Deck Height? Can you find out the mail in tunner did in contrast to the actual tuner? 2FD brother ET1(SS/SW/MTS) US Navy, Ret.

[@robb907]

@@SQUID_Road_Glide I think Trask makes really nice products. Will be interesting to see how yours turns out with the Jackpot exhaust. Keep me posted. I’ve learned a lot about these big bores since this build. I have a 160 hp 131 RGST now. It had the same dip. Our dealer here doesn’t have a trained tuner but he does a good job. All he does is run the Power Vision Autotune feature on the dyno. On this Lowrider I called Fuel Moto and talked to them about it and emailed the map back and forth. But now Billy has learned enough that he talks to them directly while the bike is on the dyno and sends them data logging. Then he makes changes with their guidance. Fuel Moto told me that the dip is partially caused by a short pipe, but also the Power Vision autotune for some reason. Either or can be manually tuned out though. My buddy’s map is tuned with the Harley tuner, which is also an autotune process on the dyno, but I think he can connect with Harley for any issues. But notice how good it did for a Harley product with no dip. My Road Glide was a little trickier to tune because it had us a lot of nice goodies on it. But Billy made it run really nice. 131 screaming Eagle cylinders with 11.5 :1 compression pistons 7.1 injectors Wood, WM8 9960 Cam .600 lift Ward +1 heads HPI 62mm throttle body S&S oil pump Baker 30 tooth compensator Rekluse Torquedrive manual clutch Trask basket Jackpot RTX Baker Grudgebox 6spd overdrive Trask vented transmission cover And I think that’s it. I don’t have any money left ha!

[@RidersShipmate]

It's me, with a new handle; SKWID Rider's Shipmate You never know who's watching you, and how what they see may inspire. S&S 129ci Kit S&S Head Bolts/ Cylinder studs/ Tapped cuffs/Roller Rockers Fueling Gorilla Rocker Shafts T-Man Head Breathers Fueling Reaper 508 Chest Race Kit T-Man No Loss air cleaner Thunder Max Tuner *HPI 70mm Throttle Body and Manifold *6.8 Scream’n Eagle fuel injectors *Evolution Stage 1 Clutch pack *Man-O-War Sprocket *Hayden Primary chain tensioner Zippers Duel Hydraulic piston and cam gear set *Other Doo-Dads Currently waiting on the Scream'n Eagle heads I sourced then sent to Johnson Engine Technology J.E.T. SilverBAK's new cylinders and cam chest is installed. Putting on heated grips. SKWID ET1(SS/SW/MTS) US Navy, Ret. Killmonger:2020 Fat Boy SilverBAK: 2021 Road Glide

[@TheHighestGodisGood]

Awesome video my brother!!! I want one!!!

[@FLYANDRIDE15]

Great video and build! New Sub 🤙💯

[@robb907]

Thank you! 😃

[@20sgcvo90]

I just did the same FM 128 kit with HD Extream heads 64TB 5.5 inj with 11.1

[@robb907]

Sweet man! Did you dyno?

[@20sgcvo90]

@@robb907 not yet, the dealer told me to put 1K on it before they will tune it. I’m at 300 miles right now. I do like the SS roller rockers and the SS oil pump does a great job to lower the engine temperature I was shocked at how cool it runs.

[@robb907]

@@20sgcvo90 interesting they want you to wait to tune it. Well good to know you’re running cooler. The 2020 pump upgrades are supposedly good to go so we’ll see how this one does because I didn’t upgrade. But heat isn’t an issue where I live, I do worry about that something though which hasn’t been a problem yet. I also run a 131 in my CVO and have about 3500 miles on it so far with the 2020 oil pump that Harley makes

[@20sgcvo90]

@@robb907 just got my bike dyno numbers in… we are within 5 HP/TQ numbers

[@robb907]

@@20sgcvo90 very nice

[@Oliviaswaxtech]

Hope your riding it! Been riding mine for 2 weeks now in Alaska!

[@robb907]

Yeah man! Was out March 29th 😎

[@crvzer]

I cant imagine the short exhaust primaries do a damn thing to help torque.

[@Breakout2018]

Nice job dude

[@robb907]

Thanks brother

[@Breakout2018]

Hey Rob you still have the super street exhaust on your bike? And do you still like it?

[@robb907]

@@Breakout2018 nope I did not have that exhaust for very long. Ended up settling on a Fuel Moto Jackpot Riot for that bike. I have had two baggers since this video that I did big bore builds on and have run with Jackpot RTX 2 into 1 on both. That’s been consistently my favorite exhaust since I found the Riot on this bike. Excellent power numbers, excellent sound. And they look pretty good. The S&S exhaust just didn’t perform well at all. Not sure why.

[@Breakout2018]

@@robb907 Thanks for the info bud. I’m searching for exhaust for my breakout. In your video it sounded awesome!! I’ll keep looking.

[@robb907]

@@Breakout2018 I have a clip of my Road Glide ST 160 hp build I did this last summer.. I have some footage that I haven’t posted yet. I’ll see if I can get that on there in the next day or two. I bet you’ll like that a lot. Still trying to figure this KZbin thing out lol.

[@randycompton5225]

I would have put new lifters with a new cam

[@therory6888]

Thanks for the video, and nice bike! 👍 And how many piston oiler gaskets did you get? 😁

[@robb907]

🤣 still just one!

[@therory6888]

@@robb907 LMAO! 👍

[@chrissmith7669]

I’ve seen seen several reports that the stock heads flow pretty darn good as is. Real easy to screw them up. Have you done any dyno runs comparing the ported to stock or the HD big valve heads? I’m thinking about the best way to go.

[@robb907]

Yes that is true, but they can’t handle more than .475 lift cams. If you want to go with a beefier for your cam then you need to change the valve springs at minimum. If you look at Fuel Motos website you can find dyno charts with just about every combination of cam and head along with different size bores. I chose to skip over stage three and go straight to stage four. I think the difference is probably 15 hp and maybe 15 foot pounds torque better with CNC ported and polished head and with lift valve springs. I hope that helps.

[@Colinmcdougall6996]

👍🏻👍🏻👍🏻

[@yasehisojlm]

Nice build and great results.. About to do the same with mine, 2020 FB 114 to 128. Looks like you kept the OEM cam plate and oil pump, is that right? If so how is it doing.? One of the things im on the fence to replace because its running just fine with stage 2.

[@robb907]

Thanks I appreciate that. Everything I have learned is that you don’t need to update past 2020 because the sumping issue has been corrected with the third gen HD pump however, I went with the S & S oil pump for my newest 131 build on my ‘22 road glide ST. Probably not necessary, but regardless just make sure that you use the seal from the stock pump or buy a brand new one for 10 bucks because without that seal, you will have problems transferring too much oil through the pinion, bearing into the crank case. if you want more info on that then i have a video I did when I installed the seal that my mechanic forgot to put for the build I did on the road glide. Basically, the $10 seal is more important than the $800 upgraded oil pump. This is the video about the seal: kzbin.info/www/bejne/mKvdo2uHhJySiKcsi=ndcAtoAXeV1yT_3d

[@dextersuarez9948]

How long did this take from start to finish (building it) yourself as a first timer?

[@robb907]

Approx 3 nights after work a few hrs per night. So probably 8-10 hrs total

[@dextersuarez9948]

@@robb907 wow that’s impressive man, I’m considering a Fuelmoto big bore pretty soon. Really appreciate the video. Thanks

[@S1000RR11]

That’s a knock sensor, (sparkler speaker thing)

[@robb907]

Yes! I figured it out when I put it back together (Spark plug sparker thingy). Editing these vids are time consuming and hard to catch all the errors. Like Woods (Wood) cam or S&S 121 (128). Quicker to build the engine haha. Thanks for watching it 😎

[@zackprete2593]

I've been debating just going with a cam or spend the money for the big bore. Did you notice a huge difference (butt dyno) from the 475 to the full BB?

[@robb907]

FUK YEAH I DID! No regrets, this thing is AMAZING. That being said, if money is tight, the 475 cam is fantastic for the time being 😎

[@aaronfowler5477]

I know it’s an older video but I had a question for ya. How did you know to have them shave off 30/1000 from your ported heads?

[@robb907]

Originally I was going to go with a stage III 10.75:1 low compression build. Then I decided to go with stage IV 11.5:1. So the math works out to shave new heads versus higher compression pistons. You end up with the same result. The heads were already CNC ported and polished with behind valve springs, so all they had to do is shave them, and ship them.

[@JorgeL1]

Oooo, bold move doing it yourself. Do you know of any educational resources for someone to learn how to do this?

[@robb907]

I got A lot of perspective from KZbin but the best video that I saw and would recommend is one that was done by cycle fanatix. He did a good job. I have a pretty extensive mechanical background as well so that helped plus my local Harley dealer is pretty flexible letting me get in and out of the dyno room and have access to the mechanic who is also a friend.

[@JorgeL1]

@@robb907 👍 thanks for the reply. I’ll check the cycle fanatix one

[@liamstandish878]

What cam, tb and headword did you use?

[@damo2664]

Hey mate great video. What risers and bars are you using?

[@robb907]

Howdy! The risers are Drag Specialties 5.5” 1-1/4” Buffalo risers, and I bought them from RevZilla. The bars are stock. www.revzilla.com/motorcycle/drag-specialties-1-14-buffalo-handlebar-risers-for-harley?sku_id=958385

[@damo2664]

Legend. Thanks for the help 👍😁🙏🏻🇦🇺

[@LonerBoi88883]

Nice video, huge difference from 475 to big bore? I think I'll hold off on doing this.

[@robb907]

Yes, huge difference for sure. Stock was 79hp/105tq (approx) 475 was 115hp/123tq Big bore 128 and 408 cam 141hp/150tq For your consideration - I ran the 475 cam for one year and had a super bad ass fun time on it. I put 3200 miles on it so I reused my S&S lifters, push rods etc. so the net loss of cost was the cost of the 475 Cam only, $200 ish. So if overall cost to do the big bore build was going to hold somebody up then they could still enjoy a stage to build, which is a ton more fun than stock. Plus it’s kind of fun to do in stages. I’ve been riding this bike around for a week now and it is ridiculously quick. Still a little too cold and the streets have a lot of sand on them still. But I can tell you It pulls right off the line and keeps going. I hope this helps… 🤘🏼

[@amphibdriver1]

@@robb907---> What is the lift on the 408 cam?

[@robb907]

@@amphibdriver1 .520

[@danpeoples1000]

@@robb907 Thank you for the insight! This is the exact build that I would like to do on my 2020 LRS - fast freeway commuter bike. Love the idea of the staged build approach.

[@roncoburn7771]

what was pinion shaft run out ?

[@johnbeardsley7360]

are u going to have to get a pilots license now?

[@fknbd808bmr]

Any temperature cooling upgrades or issues?

[@robb907]

Nope. But in Alaska we don’t have to worry much about high temps. May see 90° once or twice a year.

[@gvs5318]

So the woods 77X can makes that drastic a difference in the 131 motor?

[@robb907]

It can. Esspecially if you’re running the right exhaust. This on here has a Jackpot Riot as does mine.

[@gvs5318]

@@robb907 Thanks for the input, right now mine has the stock 131 stage 4 configuration an addition to some super duper down pipe and street cannons slip ons. I'm impressed with the 77X Dyno curve, let's try what I have and hope it comes close to your numbers

[@robb907]

@@gvs5318 Is your downpipe the screamin eagle version? Reason I ask is on my SG CVO 131 I had the Screamin Eagle header and high flow Street cannons set up. The cats were in the mufflers instead of the head pipe like they are stock. I switch to a two into one Jackpot RTX and gained 10hp and 13 foot pounds of torque. Could really feel it riding.

[@gvs5318]

@@robb907 Yes on the S.E. downpipe. I still have a few months remaining on my warranty so the research has been slow and the input fantastic. Looking at dyno charts the Jackpot 2 into 1 does rate favorably. But I'm not ready to make the leap just yet, as mentioned once the warranty expires I'll make my decision then

[@jamesweber4938]

Your accent sounds just like Kevin Baxter ? Are you from the same area ?

[@robb907]

I don’t know who that is. Is he from Alaska?

[@jamesweber4938]

@@robb907 kzbin.infoabout He is from Georgia ?

[@NormalSoMDStuff]

No Kevin Baxter is from pro twin performance in winder, georgia. He builds really great skunk works engines on youtube.

[@robb907]

@@NormalSoMDStuff nice! I’ll look him up

[@paulwest4424]

What pipe are you running?

[@robb907]

It’s a Fuel Moto Jackpot Riot I made this video last fall about the process it took to get to this pipe if you’re interested kzbin.info/www/bejne/haSsmn6tfdVpabc

[@paulwest4424]

@@robb907 awesome! I will check it out. Thanks!

[@jonathansheeder5153]

Before long, they will put sbc engines in bikes..Oh wait.

[@robb907]

Boss Hogg…. Fuk yeah!

[@bullast2046]

I mean, SH*T! You can only ride 3 days out of the year.. are you moving or something?

[@robb907]

🤣 we ride from April through October.

[@MindlessMilitia]

…1… 😂

[@robb907]

Right?!?!