Totally Updated S&S 4” Big Bore Kit Ready For Market

This new S&S 4” Big Bore Kit is announced as better than ever. The S&S’s 100”/110” big bore kit has just undergone a total redesign with new materials. Their engineers went back to the drawing board on this one and created a unique formula of ductile iron that decreases wear characteristics and allows them to increase contact between liner and fins for better heat transfer” states S&S VP of engineering Peter Winnie.

Inspired by their Pro Stock Drag Race engines, the updated big bore kit utilizes a Ductile Cast Iron liner wrapped in cast aluminum for optimum thermal conductivity and performance. 1999-2006 Twin Cam 88® engines roll up to 100ci, and 2007-17 Dyna/Softail and 2007-16 Touring become 110ci monsters!

No machining necessary and install can be done with engine still in the bike. Kit works well with stock cylinder heads, or let S&S CNC port those heads for even more power. At 10.5:1 compression it makes for a very “streetable” and dependable engine that also responds well to performance cams. Available only within the USA at this time. More info at S&S 4” Big Bore Kit .

8 Responses to “Totally Updated S&S 4” Big Bore Kit Ready For Market”

  1. 1 rebel Mar 15th, 2018 at 9:38 pm

    i believe in S&S, i’m waiting.

  2. 2 EVOFAN Mar 15th, 2018 at 11:25 pm

    Interesting. Screamin’ Eagle 4″ bore direct bolt on Twin Cam Cylinders don’t seem to have this problem (that I know of). I wonder what the diff is? I know JIMS does final machining on those for HD. Super thin (.030″) at the bottom/spigot. Material difference?

  3. 3 Hdrider Mar 16th, 2018 at 7:09 am

    Sounds like the earlier S&S big bore kit required a major redesign due to excessive wear and overheating. I wonder if they are making any accomodations to the people who installed the old version?

  4. 4 Calif Phil Mar 16th, 2018 at 7:57 am

    I just ordered two kits this week. I have faith in S&S products.

  5. 5 Shanedrive Mar 16th, 2018 at 8:05 am

    what problem? I never heard of any problem w/S&S’s 4″ kits. I only heard they ceased production because of patent issues. See Cyril’s article here:

  6. 6 S&S Cycle Mar 16th, 2018 at 9:10 am

    We appreciate the unsubstantiated speculation (for the entertainment value!), but the redesign on our 4″ cylinders was based purely on finding a better way to do it. Chrome moly is not a bad solution for thin wall liners (several others use it), but like many of our parts, we are always looking for improvement. We’ve been working on a unique formula of Ductile Cast Iron and it made sense to roll it out in the 4″ cylinders first.

  7. 7 Woody's Mar 16th, 2018 at 10:21 am

    Thanks for the added info, S&S. Should save a lot of bandwidth. Love me a cast iron bore

  8. 8 Rhino May 9th, 2018 at 6:28 am

    Was going to buy the old 110 # 910-0598 and 910-0599.What is the number of the newer product??.

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Cyril Huze