The best big bore kit for twin cam 88 In 2020 [Top 2 Picks]

Last Updated on June 29, 2020 by Atiqul Islam

Introduction- The stock twin cam 88 is amazing no doubt but after riding your Harley for a couple of years you might be willing to give it a little performance boost.

If that is the case then try adding the best big bore kit for twin cam 88. Not only does it give more power, but it also increases throttle and makes your bike more smooth at high speed. It enhances the overall performance of the bike by significantly increasing horsepower.

You might not necessarily NEED a big bore kit but if you ever wanted to unleash the twin cam’s true potential, you can do so by adding a big bore kit.

If you want to more about these, check out our picks for the best bore kits in 2020 down below


                                                S Cycle 97&Prime, Big Bore Kit Black


Overview and Construction

S & S have a huge customer base consisting of Harleys and they have parts for Panheads, big twin Evos, Sportster and not to mention the twin cams. The Bore matches nicely with the factory finish of the twin cams which makes them a reliable brand when it comes to choosing any parts regarding Harleys

This s&s 97 big bore kit comes with a piston set, gaskets, and S & S cylinders. They even include compression and oil scraper rings. The kit itself works perfectly with stock cylinder heads. 

Bore size

The S&S believes in the concept that a larger bore offers better performance. A large bore allows for better displacement and since the 97 is currently the largest one available it definitely stands out in the performance category.

Sometimes a large bore can cause issues with adjustments. The S&S 97″ Big Bore Kit despite being 3.927inches  with 96.89 cu in, it fits perfectly with the stock heads.

Because of the comparatively large size of the bore, the valves are also big which mean bigger valve openings for more air and fuel intake and in turn more power


As far as performance goes the kit noticeably enhances the overall performance. It takes a long break-in period but can take more throttle and becomes way smoother than stock. The low-speed operation is also good.

Installation  Procedure

Setting up the entire kit is difficult. Although S&S takes care of all the factors related to parts compatibility and parts ratio and solves any clearance issues with all parts, the installation is still difficult.

You would need to have some idea about what goes where and even if you do, setting up the entire thing is time-consuming.

  • Large fin area offers heat dissipation
  • Currently the largest bore
  • Silver coat finish matches perfectly
  • Larger bore offers better power
  • Requires no flywheel rebounding
  • Difficult to install


Twin Cam Black Big Bore Kit for Harley Davidson

Overview and Construction

The S&S 95 in. Twin Cam is made out of premium grade aluminum casting and cast iron which means it’s pretty sturdy. These come in two finishes. One is the silver-coated finish another is the black finish which complements the HD finishes of the twin cams.

The bore comes with cylinders, rings, wrist pins, both head, and base gaskets and pistons

Bore Size

The S&S 95s bore size is smaller than the 97 one. The 95s size is 3.875 inches that give 94.34 cu in. The big bore kit works well with the existing stock head


The 95 also performs very well and allows for smooth throttle and noticeably enhanced performance.

But, how does it differ from the 97?

The difference between a 95 and a 97 lies with the size. The difference in the size is very small but causes some significant change.

The bigger the bore and the thinner the wall of the bore, the faster it’s pistons will get worn out. This means with a bigger bore you will have to reinvest more on pistons than a smaller one.

However, if you think purely performance-wise a bigger bore will get you more displacement. Meaning the 97 will have a slight advantage over the 96 but at a higher cost.

Overall the 95 will last longer but the 97 will perform slightly better. Both of them require the same long break-in period.

Installation Procedure

It comes with all the necessary parts that allow you to turn your 88 in. engine into a 95 in. The compression ratio with the stock head is 9.7:1 and everything seems to fit perfectly as S&S already takes care of the parts compatibility but you will need someone with experience to install it because it is a difficult task and is time-consuming.

  • Comes in two different finishes
  • Comes with all the necessary parts
  • Pistons last longer
  • Premium grade construction
  • Allows smooth throttle
  • Less displacement than 97

Final Verdict

The slightest changes can turn out to be a big difference when you take everything into consideration. But to get more power and a smoother transition in speed you will need a big bore kit. As for our pick as the best big bore kit for twin cam 88, the S&S 97 BORE gets our vote solely because of the slightly bigger size. 

The big bore kits are usually difficult to install. You will have to have your fair share of knowledge if you want to install it yourself. Be sure to consider the Bore kits we talked about to significantly increase twin cam’s power and performance.

Atiqul Islam

Welcome to my site. I have interest in auto. I deal with automotive products. I have years of experience in this field. I will share my knowledge of this site.

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