Topic: SUBURBAN M8 124 or 130 CI PISTONS (Read 4719 times)

2018CVOGS · « **on:** December 29, 2019, 03:34:21 PM »

Searched the threads but cannot find anything on Suburban H-D 124 flat top or the high compression pistons. I’m researching options for my 2018 CVO RG. The idea of not having to replace the cylinders and going with pistons, hot cam, new tuner, and TB sounds intriguing.

My current setup is a fullsac headpipe and cores, SE power cam, and SE tuner. Warranty ends 1/2020 so am looking for more torque and HP without compromising reliability for the 5-7 days road trips.

Does anyone have this setup or know anyone that does?

https://suburbanharley.com/Parts-Catalog-M8-Pistons

FLSTFI Dave · « **Reply #1 on:** December 30, 2019, 08:05:32 AM »

Looking at the Suburban link. All those will require new cylinders.

There is no way to take a 117 inch motor, and make it have more displacement, which is more cubic inches with out doing one of two things. The first and easiest is bigger cylinders to accommodate bigger pistons, the 117 to 124. The other option is to give the motor more stroke.

It is possible to put bigger cylinders on and still have a highly reliable motor when done with the right parts and the right builder. Key is all parts designed to work together, compression low enough to keep cranking pressures close to stock.

I am planing to take my 19 CVO Road Glide to 130 inches. I usually take two trips of about 12 days each on my bike. I have a build motor in my 2013 with larger cylinders, 110 to 117. Much higher compression, head work and so on. Bike has no problem doing 600 mile days. My 19 will make more power with less compression. So coast to coast should be no issue.

Here is a link to the suburban kits. They sell the pistons separate if you want to build your own kit.
https://suburbanharley.com/Performance-Kits-Milwaukee-Eight

2018CVOGS · « **Reply #2 on:** December 30, 2019, 10:03:31 AM »

Thanks for the detailed response, FLSTFI Dave. I’d previously looked at the 128 cylinder and piston kits offered by FM and S&S. My dealer had a horrible experience with FM so refuse to use them again. If S&S cylinders weren’t branded with their logo, I would have gone this route.

Will give Suburban a call today for more info.

FLSTFI Dave · « **Reply #3 on:** December 30, 2019, 10:31:59 AM »

I do not believe the S&S M8 cylinders are branded. Many other companies are using S&S cylinders for their kits. Friend just built his with S&S cylinders and I did not see their markings. I'll look again in the next day or two.

Prostock · « **Reply #4 on:** December 30, 2019, 01:42:47 PM »

You can eliminate the S&S logo by drilling the rivets out. I am a huge fan of suberban speeds Mahle pistons. I have 2 M8 107 bored to 120's with there flat tops out in the field. We bored 114/117 harley cylinders to accomplish this. I believe you can bore your 117 to 124 but need S&S to go 130. Rick has cylinder and pistons sets available.

havenolife · « **Reply #5 on:** December 30, 2019, 02:28:37 PM »

Quote from: 2018CVOGS on December 30, 2019, 10:03:31 AM

Thanks for the detailed response, FLSTFI Dave. I’d previously looked at the 128 cylinder and piston kits offered by FM and S&S. My dealer had a horrible experience with FM so refuse to use them again. If S&S cylinders weren’t branded with their logo, I would have gone this route.

I have never heard to many people bad mouth FM

2018CVOGS · « **Reply #6 on:** December 30, 2019, 02:50:38 PM »

Directly from S&S after my inquiry. Good to know the rivets can be removed....not looking to advertise.

scotman623 · « **Reply #7 on:** December 30, 2019, 04:55:18 PM »

I’m patiently waiting for my 19 CVO Rg to be finished, went too 128 using SS parts and the builder did the stage 2 head work...Looking forward to joining the 150-150 crowd...😎

Fullsac Performance · « **Reply #8 on:** December 31, 2019, 04:56:42 AM »

Quote from: 2018CVOGS on December 29, 2019, 03:34:21 PM

Searched the threads but cannot find anything on Suburban H-D 124 flat top or the high compression pistons. I’m researching options for my 2018 CVO RG. The idea of not having to replace the cylinders and going with pistons, hot cam, new tuner, and TB sounds intriguing.

My current setup is a fullsac headpipe and cores, SE power cam, and SE tuner. Warranty ends 1/2020 so am looking for more torque and HP without compromising reliability for the 5-7 days road trips.

Does anyone have this setup or know anyone that does?

https://suburbanharley.com/Parts-Catalog-M8-Pistons

The 4.185 Mahle pistons from Suburban are very good, worth the money, and will take your 4.5" stroke 117 to 124" with a bored OEM barrel as stated previously. I have done a couple of builds with their 4.185" pistons in a bored OEM CVO cylinder, no issues. If you decide to go this route, be sure you have a competent machinist bore your cylinders or do an exchange with Rick at Suburban. The quality of the machining is critical for proper ring seal and single digit leak down numbers. If I was buying barrels, I would go with Suburbans 130" kit. These are S+S barrels with Suburban's Mahle pistons and machine work. There is a difference.
I attached a dyno chart from the 124" build comparing TTS cams.

Steve@fullsac.com

FLSTFI Dave · « **Reply #9 on:** December 31, 2019, 07:49:45 AM »

Quote from: 2018CVOGS on December 30, 2019, 02:50:38 PM

Directly from S&S after my inquiry. Good to know the rivets can be removed....not looking to advertise.

Looked at my friends bike again yesterday afternoon. S&S logo like pictured is on the very bottom of the left / shifter side of the bike on the bottom. I did not even notice the S&S logo on while the bike was on the stand, had to bend down to see it.

I too do not want to advertise, but think I'll leave the logo there as its really not very noticeable.

yobtaf103 · « **Reply #10 on:** December 31, 2019, 05:41:56 PM »

Yes the Suburban kits do look good, if you want to go 130", build on another forum using their 126" Mahle pistons/ S&S cyl gone 160/150

Also if want 130" Scott Tomsu STFU motorcycles sells kits using custom CP Carrillo pistons/S&S cyl, not sure if marked

Another option for the sleeper look but 128" is the Zippers Kit, no markings look factory, CP Carillo piston choice of 2 domes

scotman623 · « **Reply #11 on:** December 31, 2019, 07:01:22 PM »

So many different options for the M8 platform to build LOTS of power... Great for us the customers and the builders... My 128 build from Hillside should be completed end of next week, Then off to Daytona to visit my father and test the bike out 😎

Unbalanced · « **Reply #12 on:** December 31, 2019, 07:43:30 PM »

Another 2 kits out there are Rev Performance and Dragos Kit

Believe Drago goes to either a 131 or 135, don’t know if Frank is still building a 160 M8

What are CI pistons in the title is it a miss print for CP?

Threephase · « **Reply #13 on:** December 31, 2019, 09:55:33 PM »

Quote from: Unbalanced on December 31, 2019, 07:43:30 PM

Another 2 kits out there are Rev Performance and Dragos Kit

Believe Drago goes to either a 131 or 135, don’t know if Frank is still building a 160 M8

What are CI pistons in the title is it a miss print for CP?

I believe he is referring to cubic inches.

FLSTFI Dave · « **Reply #14 on:** January 01, 2020, 09:25:31 AM »

Quote from: yobtaf103 on December 31, 2019, 05:41:56 PM

Yes the Suburban kits do look good, if you want to go 130", build on another forum using their 126" Mahle pistons/ S&S cyl gone 160/150

He is on this forum also.

HD Street Performance · « **Reply #15 on:** January 01, 2020, 09:27:02 AM »

I have been using unfinished S&S cylinders and the Mahle pistons very successfully. I season them, bore and hone in plates on a Sunnen CV616. Last set was skirt coated by line2line and made 160hp @ 126" 4 3/8" stroke. Owner reports it is very quiet.
Have another set in work 130" same deal @130" 4 1/2" stroke.

yobtaf103 · « **Reply #16 on:** January 01, 2020, 12:50:43 PM »

Quote from: HD Street Performance on January 01, 2020, 09:27:02 AM

I have been using unfinished S&S cylinders and the Mahle pistons very successfully. I season them, bore and hone in plates on a Sunnen CV616. Last set was skirt coated by line2line and made 160hp @ 126" 4 3/8" stroke. Owner reports it is very quiet.
Have another set in work 130" same deal @130" 4 1/2" stroke.

Yes Sir, Joe sent me a youtube link of it @ 2nd heat cycle start up, real quiet motor totally belies what it is amazing.

Unfinished ,in what way? S&S 4.250 taken to 4.280 what spigot thickness remains 0.065"

HD Street Performance · « **Reply #17 on:** January 01, 2020, 01:18:10 PM »

No the bores slightly under and are not honed. Intended for a finished bore of 4.250, I bore to 4.275 and hone the rest.

FLSTFI Dave · « **Reply #18 on:** January 02, 2020, 05:18:30 AM »

Quote from: yobtaf103 on January 01, 2020, 12:50:43 PM

Yes Sir, Joe sent me a youtube link of it @ 2nd heat cycle start up, real quiet motor totally belies what it is amazing.

Unfinished ,in what way? S&S 4.250 taken to 4.280 what spigot thickness remains 0.065"

You should hear that motor in person. Zero Valve train noise, mechanically the motor is quite than a stock M8. You can hear the cam lope in the exhaust. It is an extremely strong motor. Looking at the bike there are only two signs its not stock, the D&D exhaust and the sound of the exhaust. Or if you look really hard you could see S&S on bottom of cylinder.

Ghost__Rider · « **Reply #19 on:** June 03, 2020, 11:12:57 AM »

I just built my 2017 with Suburban SPeed 130 kit. Only mistake I made was I scrimped on the heads. Instead of waiting on CNC ported heads, I sent them my stock heads and had the the ports cleaned up.
Made 146 hp/149tq , I love it... but next time I'm not gonna be a tight ass and get better heads.

I exploded my compensator in 1500 miles..........so it makes lot tq

FLSTFI Dave · « **Reply #20 on:** June 04, 2020, 06:39:10 AM »

Quote from: Ghost__Rider on June 03, 2020, 11:12:57 AM

I just built my 2017 with Suburban SPeed 130 kit. Only mistake I made was I scrimped on the heads. Instead of waiting on CNC ported heads, I sent them my stock heads and had the the ports cleaned up.
Made 146 hp/149tq , I love it... but next time I'm not gonna be a tight ass and get better heads.

I exploded my compensator in 1500 miles..........so it makes lot tq

Not sure its the heads. Friends 126 with cleaned up stock heads is over 160/150.

Same head work done on my heads, and i'm over 160/160.

HD Street Performance · « **Reply #21 on:** June 06, 2020, 09:04:19 AM »

I use the Mahle pistons. They have proven to be very reliable when fit properly and honed the same. The stock cylinders go up to 4.125". I am now using a sleeved stock cylinder and have also bought unfinished S&S cylinders which I true true the tops and bottom, bore and hone up to and larger than 4.250, and season them with heat cycles. Very soon KB will be releasing large bore line2line coated M8 pistons which will be a nice addition. I am a distributor for KB pistons.

Ghost__Rider · « **Reply #22 on:** June 11, 2020, 02:47:29 PM »

FLSTFI Dave, What pistons you running? I see you used different cams than I did. I used TTS 250 cams and Suburban speed flattop pistions. I'm 11.5:1 compression. I see your lot more compression. Can you run on pump gas when it's hot?

HD Street Performance · « **Reply #23 on:** June 11, 2020, 02:52:39 PM »

I did the work for Dave. He is using the 130" pistons from Suburban (Mahle) flat tops and S&S cylinders. Heads milled and ported.

Ghost__Rider · « **Reply #24 on:** June 11, 2020, 03:04:34 PM »

Ok, I'm using same pistons then, but heads not milled.

FLSTFI Dave · « **Reply #25 on:** June 12, 2020, 06:30:20 AM »

Quote from: Ghost__Rider on June 11, 2020, 02:47:29 PM

FLSTFI Dave, What pistons you running? I see you used different cams than I did. I used TTS 250 cams and Suburban speed flattop pistions. I'm 11.5:1 compression. I see your lot more compression. Can you run on pump gas when it's hot?

Mahle pistons with milled heads.

So far no issue with heat, hasn't been over 91 degrees yet. 93 gas is readily available in my area, and not hard to find 93 no ethanol. I have also road the bike through out North Western AR in mid 80 degree weather on 91 octane. Bike did fine, both in a group ride in the mountains and pushing it a bit. I have also done a 750 mile day in just under 10 hours on it.

Fullsac Performance · « **Reply #26 on:** June 12, 2020, 08:50:00 AM »

Quote from: Ghost__Rider on June 11, 2020, 03:04:34 PM

Ok, I'm using same pistons then, but heads not milled.

You're still thinking about what my finger pointed at when we only made 147 HP. Get set of Don's heads and I will tune it again for free!

All done with the burn outs and pushing it home?

lol....
SG

Ghost__Rider · « **Reply #27 on:** June 12, 2020, 01:15:20 PM »

Quote from: Fullsac Performance on June 12, 2020, 08:50:00 AM

You're still thinking about what my finger pointed at when we only made 147 HP. Get set of Don's heads and I will tune it again for free!

All done with the burn outs and pushing it home? lol....
SG

Smarty Pants............I'm good with the 147 hp. Just know there's more in there with different heads. I would if you weren't 1600 miles from here.

Fullsac Performance · « **Reply #28 on:** June 12, 2020, 01:29:37 PM »

Quote from: Ghost__Rider on June 12, 2020, 01:15:20 PM

Smarty Pants............I'm good with the 147 hp. Just know there's more in there with different heads. I would if you weren't 1600 miles from here.

If you bring your wife, you can stay at my house.

SG

Author Topic: SUBURBAN M8 124 or 130 CI PISTONS (Read 4719 times)