When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
S&S 131 vs HD 131 engine/kit cylinder wall thickness
Hey folks,
I'm just starting my research. I hear a bunch of crap about the HD 131 kit/engine cylinder walls being too thin.
So my question is ...What is the thickness of the Harley 131 engine and kit walls ?
My second question is .. What is the thickness of the S&S cylinder walls ?
Lastly, how many 131 engines have failed due to the thin walls ? I know this is subjective. But maybe a failure or failures said to be caused by the thin walls..
I don't have a specific answer to your question, but given a choice between S&S or HD parts, history has shown that S&S parts are almost always superior in design and quality to HD parts
I'm just starting my research. I hear a bunch of crap about the HD 131 kit/engine cylinder walls being too thin.
So my question is ...What is the thickness of the Harley 131 engine and kit walls ?
My second question is .. What is the thickness of the S&S cylinder walls ?
Lastly, how many 131 engines have failed due to the thin walls ? I know this is subjective. But maybe a failure or failures said to be caused by the thin walls..
Regards
Sum
I don't have that spec but the Harley 131" cylinders have steel liners as far as I know. I've not heard of failures because of thin walls. My 131" build with custom fitted pistons in Harley cylinders is doing fine.
S&S doesn't do 131" kits.
S&S 131 "kit" 0931-0973 .. a kit I suppose .. of course need some other toys.
That's a stroker kit, have to break the cases down, not the same bore as the Harley cylinders to compare thickness.
I might add that if I was going to break the cases apart it would be for larger than a 131" motor.
That's a stroker kit, have to break the cases down, not the same bore as the Harley cylinders to compare thickness.
I might add that if I was going to break the cases apart it would be for larger than a 131" motor.
From what I understand, the stock 107 block cant handle anything larger 124". But .. if going to a Darkhorse M8 crank .. other things can happen. The builder told me I could go to a 143 .. but I want the bike to be ridable and NOT snap belts or present the need to go to a chain.
Anyway .. not having alot of success finding out the information requested in the original post. Im a data guy .. if its out there .. I should be able to find it.
Heres the first response from S&S .. which really doesnt answer my questions.
quote
S&S
Oct 25 at 11:51 AM
TECHMAIL VIOLA <techmail@sscycle.com>
To: sumncguy Im trying to find out what the different between your M8 131 cylinders and the OEM Crate 131 cylinders. I keep hearing that the Harley 131 cylinders are sub standard due to thickness. Where do yours stand in comparison ?
The S&S 131" kit has a thicker liner and better materials. The 131" kit works in conjunction with our 4 5/8" M8 flywheel which also has a better runout compared to the stock flywheel. You can run a gear drive cam instead of a chain drive cam.
--Thank You,
Technical Support
S&SŽ Cycle, Inc. | 14025 County Highway G, Viola, WI 54664
From what I understand, the stock 107 block cant handle anything larger 124". But .. if going to a Darkhorse M8 crank .. other things can happen. The builder told me I could go to a 143 .. but I want the bike to be ridable and NOT snap belts or present the need to go to a chain.
Anyway .. not having alot of success finding out the information requested in the original post. Im a data guy .. if its out there .. I should be able to find it.
Heres the first response from S&S .. which really doesnt answer my questions.
quote
S&S
Oct 25 at 11:51 AM
TECHMAIL VIOLA <techmail@sscycle.com>
To: sumncguy Im trying to find out what the different between your M8 131 cylinders and the OEM Crate 131 cylinders. I keep hearing that the Harley 131 cylinders are sub standard due to thickness. Where do yours stand in comparison ?
The S&S 131" kit has a thicker liner and better materials. The 131" kit works in conjunction with our 4 5/8" M8 flywheel which also has a better runout compared to the stock flywheel. You can run a gear drive cam instead of a chain drive cam.
--Thank You,
Technical Support
S&SŽ Cycle, Inc. | 14025 County Highway G, Viola, WI 54664
Office 608-*627-1497
Unqoute
With the M8 motor there is a lot to choose from for sure. How well the associated parts like belt and transmission hold up has a lot to do with how you ride. A 165 torque bikes can run without a chain drive if the belt is adjusted correctly. You can make a lot of power without the expense of opening up the cases.
I'll make a guess lol. The 110 and 117 drop on kits for the twin cam have been around for several years now. They seem to be made with the same concept of design and materials as the m8 kits are. The spigot on the 117 kit I have is .036 thick. We can assume that HD an s&s are probably very close to that same number...maybe a bit thicker but definitely not thinner lol. I doubt one or the other has some magical metal that allows them to be bigger than the next...notice how they both landed on the same number with all of these types of cylinders? Is s&s better? Maybe not better but they have better quality control so fewer bad parts make to the customer...just my opinion. I'm going be using a HD 117 kit in my bike and I have no problem doing so. I have measured the cylinders to make sure theyte round and straight though...but I'd do that with any brand.There were some issues with some of the earlier twin cam cylinders but based on what you read on the trusty internet that those issues have been resolved a while ago. Sure seems like they have them figured out. I know that wasn't a perfect answer but hopefully it helps.
From what I understand, the stock 107 block cant handle anything larger 124". But .. if going to a Darkhorse M8 crank .. other things can happen. The builder told me I could go to a 143 .. but I want the bike to be ridable and NOT snap belts or present the need to go to a chain.
Anyway .. not having alot of success finding out the information requested in the original post. Im a data guy .. if its out there .. I should be able to find it.
Heres the first response from S&S .. which really doesnt answer my questions.
quote
S&S
Oct 25 at 11:51 AM
TECHMAIL VIOLA <techmail@sscycle.com>
To: sumncguy Im trying to find out what the different between your M8 131 cylinders and the OEM Crate 131 cylinders. I keep hearing that the Harley 131 cylinders are sub standard due to thickness. Where do yours stand in comparison ?
The S&S 131" kit has a thicker liner and better materials. The 131" kit works in conjunction with our 4 5/8" M8 flywheel which also has a better runout compared to the stock flywheel. You can run a gear drive cam instead of a chain drive cam.
--Thank You,
Technical Support
S&SŽ Cycle, Inc. | 14025 County Highway G, Viola, WI 54664
Office 608-*627-1497
Unqoute
Sounds to me like you have the right ideas....
Darkhorse crank works have outstanding bottom end **** for engines. Most definitely the right direction. I wouldn't be afraid of converting to chain drive, but I don't think you'll have to. I had a 124" S&S engine with B2 Heads on a long chopper that was belt driven. I TRIED to break the belt and couldn't. Most that go higher in HP convert to chain drive anyway, unless they're highway riding and like upper end torque better than drag racing.
There's several guys here that have 160+ builds. Would be interested to hear from them on belt or chain.
To be honest, the only reason I dont like the chain is that theres more maintenance than with a belt. A little noisier too. Reminds me of riding the Lilco trails on Long Island when I was a kid.
I occasionally hit it off the line when I'm trying to impress/show off , but mainly I'm a roll on kind of guy .. like to feel the torque and pull as I run through the gears. There alot of history with this bike which is/are dictating where I go next. Ive attached one quote I got for aftermarket. I also got a quote from a Harley dealership for a HD crate 131 install. The engine is 6200 bucks, install labor isnt to bad .. but once they added stuff to fix the issues with that engine, it came close to this estimate. If your all interested, I can go into the details of this bike and how I arrived at .. well .. what I'm looking at now.
7 Surprising Harley-Davidson Products that Are Not Motorcycles
Slideshow: The bar-and-shield logo shows up on far more than motorcycles, some of the company's most unexpected products have nothing to do with riding.
Slideshow: From the troubled AMF years to modern misfires, these bikes earned reputations for reliability issues, questionable engineering, or disappointing performance.
Crazy Bunderbike Build Looks Amazing, But Is It Impossible to Ride?
Slideshow: The Swiss custom shop has taken a Harley Softail and stretched it into something so long and low that it looks closer to a rolling sculpture than a conventional motorcycle.
Engraved Rebellion: Inside Bundnerbike's Glam Rock II
Slideshow: A standard cruiser becomes an intricate metal canvas in the hands of a Swiss custom house known for pushing Harley-Davidson platforms far beyond their factory brief.
Slideshow: Harley-Davidson's challenges aren't abstract; they show up in dropping shipments, shrinking dealer traffic, and strategic decisions that aren't yet translating into growth.
S&S 131 vs HD 131 engine/kit cylinder wall thickness
, but mainly I'm a roll on kind of guy .. like to feel the torque and pull as I run through the gears. There alot of history with this bike which is/are dictating where I go next. Ive attached one quote I got for aftermarket. I also got a quote from a Harley dealership for a HD crate 131 install. The engine is 6200 bucks, install labor isnt to bad .. but once they added stuff to fix the issues with that engine, it came close to this estimate. If your all interested, I can go into the details of this bike and how I arrived at .. well .. what I'm looking at now.
