What is an R&R Motorcycle Engine? [Specs & Review]

R&R engines are high-performance aftermarket V-twins sold in small quantities. The American manufacturer offers a complete line of billet engines with displacements of 113-155”. The power of these amazing engines can go up to an eye-popping 173 HP!

If you want to find out more about these legendary R&R engines, this post is for you.

From the specifications to the key facts on the manufacturer, we at PowerSportsGuide have compiled everything into this R&R engine review!

What is an R&R Engine?

R&R motorcycle engines are manufactured by R&R Cycles Inc. The company was established in 1995 and is now headquartered in Manchester, New Hampshire. R&R Cycles claims itself to be “the leader in American V-Twin performance,” and with good reason.

Besides a wide variety of aftermarket performance parts and packages, you can find some complete big-inch V-Twin engines in the company’s offering.

These power mills are widely popular among performance-minded riders and custom motorcycle builders.

Let’s get down to the nitty-gritty and talk about them in detail!

R&R Engine Reviews

As the old saying goes, “There’s no replacement for displacement.”

And when it comes to R&R engines, we talk about serious displacements ranging from 113” up to a whopping 155”! To be more specific, production R&R engines are as follows:

  • R&R 113”
  • R&R 127”
  • R&R 139”
  • R&R 147”
  • R&R 155”

These big engines not only provide more torque and power, but they also tend to be more durable than their smaller brothers. R&R engines are built in-house but they utilize some parts from external suppliers like S&S.

Each R&R engine is available with either a raw, polished, or black finish.

R&R 113” Engine Review

Despite its serious size, the 113” is the smallest engine in the R&R fleet.

This unit is a unique blend as it’s built on high-quality S&S lower-end components, which are complemented with an R&R carb and top components.

Since these parts are perfectly matched, the R&R 113” produces great reliability and performance.

Another key advantage of this size is that it fits the frame of much smaller stock and custom-built bikes.

Ket key specifications of the R&R 113” engine are as follows:

  • Displacement: 113 cu in
  • Horsepower: 125-130 HP
  • Bore: 4.000”
  • Stroke: 4.500”
  • Compression: 11.00:1
  • Carb: S&S Super “G”

R&R 127” Engine Review

The R&R 127 engine is intended to be a replacement V-twin engine that will fit in a stock Softail chassis. However, it can also act as the heart of any custom bike.


  • Displacement: 127 cu in
  • Horsepower: 135-140
  • Bore: 4.250
  • Stroke: 4.500
  • Compression: 11.00:1
  • Carb: S&S Super “G” With Thunder Jet

R&R 139” Engine Review

If you are looking for some more power, you can’t go wrong with the 139” R&R engine rated at 145-150 HP.


  • Displacement: 139 cu in
  • Horsepower: 145-150 HP
  • Bore: 4.375
  • Stroke: 4.625
  • Compression: 11.00:1
  • Carb: S&S D W/3 Thunder Jets

R&R 147” Engine Review

The R&R 147” is the bigger brother of the 139” engine. They feature the same 4.625” R&R flywheel assembly and case, but the former comes with a bigger bore, 4.5” billet cylinders.

The key specifications of the 147” engine are as follows:

  • Displacement: 147 cu in
  • Horsepower: 155-160
  • Bore: 4.500
  • Stoke: 4.625
  • Compression: 11.00:1
  • Carb: S&S D W/3 Thunder Jets

R&R 155” Engine Review

The flagship R&R 155” is one of the most powerful V-twin motorcycle engines available off the shelf.

Just like its 139” and 147” counterparts, the R&R 155” also utilizes the 4.625” R&R flywheel assembly, which is completed with two 4.60” cylinders mounted on a heavy-duty billet crankcase.

This power mill is the most powerful engine in the R&R lineup with an incredible performance of 168-173 HP.


  • Displacement: 155 cu in
  • Horsepower: 168-173 HP
  • Bore: 4.600”
  • Stroke: 4.625”
  • Compression: 10.8:1
  • Carb: S&S D W/3 Thunder Jets

R&R Engine Specs Chart

For your convenience, we’ve compiled the key specifications of R&R engines into one chart:

ModelDispl. (cu in)HPBore (“)Stroke (“)Compression
R&R 113″113125-1304.0004.50011.0:1
R&R 127″127135-1404.2504.50011.0:1
R&R 139″139145-1504.3754.62511.0:1
R&R 147″147155-1604.5004.62511.0:1
R&R 155″155168-1734.6004.62510.8:1

Disclaimer: These charts are for informational purposes only! For more information, please check the official factory manuals!

Takeaways – FAQs About R&R Engines

As a takeaway, we’ve answered the most frequent questions about R&R engines!

What Size Engines Does R&R Make?

R&R Cycle offers complete engines with displacements from 113” up to 155”.

How Much Horsepower Does an R&R Engine Have?

The HP ratings of R&R engines range from 125 up to 173 HP:

  • R&R 113” engine: 125-130 HP
  • R&R 127” engine: 135-140 HP
  • R&R 139” engine: 145-150 HP
  • R&R 147” engine: 155-160 HP
  • R&R 155” engine: 168-173 HP

However, the final HP and torque figures depend on many factors like the exhaust system and other features on the bike.

How Much Do R&R Engines Cost?

As a rule of thumb, the prices of R&R motorcycle engines range from $9,000 up to $15,000.

Compared to competitor models R&R engines seems quite expensive, but don’t forget that these units are custom built with high-quality materials to the highest of standards.

They also provide industry-leading performance and durability.

Is R&R a Harley Engine?

Contrary to popular belief, R&R engines are not manufactured by Harley-Davidson. Instead, R&R is an aftermarket V-twin engine brand that offers replacement engines for Harley-Davidsons and other V-twin motorcycles.

Is R&R Cycle Still in Business?

Yes, to the delight of many performance-minded riders, R&R Cycle is still in business. You can find out more by contacting the manufacturer here.

Are R&R Engines Any Good?

Yes, R&R engines have built a reputation for durability, reliability, and outstanding performance. This is why R&R is one of the most popular brands in the big-inch V-twin segment.

The only challenge might be finding a reputable dealer in your area!





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