What Are Stroker Kits, And How Do They Increase Torque?

An alternative to cylinder boring, a stroker kit is an effective but labour-intensive route to power gains
What Are Stroker Kits, And How Do They Increase Torque?

Stroker kits include specially developed engine parts that lengthen the stroke of the piston within an engine’s cylinder, allowing it to travel further up and down each time. The lengthened piston stroke increases the amount of air and fuel forced into the cylinder, boosting the overall power of the combustion cycle and delivering more energy to the crankshaft, resulting in more torque delivered to the transmission and the vehicle’s wheels.

Venturing away from original manufacturer parts can cause some drawbacks. With a stroker kit installed, the piston has to travel further during its reciprocation, resulting in more stress placed on the cylinder, piston and the surrounding components. This means other aftermarket modifications may need to be introduced so that the rest of the powertrain can cope with the additional torque. An upgraded crankshaft will almost certainly need to be installed, as any consequential vibrations of an improperly fitted or weak crankshaft can become a serious issue for the rest of the powertrain.

The contents of a Titan Motorsport stroker kit for an R35 Nissan GTR
The contents of a Titan Motorsport stroker kit for an R35 Nissan GTR

Stroker kits result in more torque in the low rev range, but the engine’s ability to reach high revs will be hindered due to the increased travel in the piston’s movement, meaning a stroker kit can decrease the responsiveness of an engine. Some people avoid installing a stroker kit as it can interfere with the natural character of the powertrain, but the additional gains may be worth it if you’re looking for maximum power gains at the wheels.

A stroker kit is a relatively complex modification, so unless you’re an experienced home mechanic, we’d recommend consulting with a professional to install one. The engine will need to be disassembled, critical components replaced, and everything carefully reassembled, so it’s a big job. However, the power gains associated with a stroker kit are nothing to be sniffed at, so it may be worthwhile if you are looking to eke out every ounce of power from your car’s engine.

What Are Stroker Kits, And How Do They Increase Torque?

Stroker kits tend to be more common for naturally aspirated engines, where extra capacity is one of the most reliable ways of making more power. In a turbocharged engine, increasing boost or fitting larger turbos is usually a cheaper way of making more power than fitting a stroker kit.

Have you ever thought about installing a stroker kit? If you have already installed a stroker kit, how much more power have you gained as a result? Comment with your experiences below.

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Comments

cherniydiavel

I prefer keeping a good rod/stroke ratio in my engines. When I overhauled my Ford, I installed a long rod stroker kit. Basically, you keep the same displacement, but you get longer rods and a smaller compression height in the pistons. This has many benefits… lower vibration, stronger vacuum, better cylinder swirl and resistance to detonation, more torque all around, less cylinder/piston wear… performance isn’t just about displacement!

01/26/2017 - 17:32 |
62 | 0

What year/engine did you do it with?

01/26/2017 - 21:51 |
2 | 0

yeah!
I’m doing the same in my …. miata
going 1.7L with
+7mm rod lenght (+5.25%)
18% lighter piston
and a tad lighter conrod.

all good!

01/27/2017 - 16:09 |
6 | 0
Freddie Skeates

The only way you can make me torque is if you stroke my crankshaft, if you know what I mean

01/26/2017 - 17:35 |
20 | 30

what

01/26/2017 - 18:14 |
2 | 2
Anonymous

What are the power benefits of a kit? How much power can you make?

01/26/2017 - 18:35 |
0 | 0
Anonymous

In reply to by Anonymous (not verified)

Depends on the engine. It’s usually a fairly linear increase (At least from what I’ve read about stroker modifications), so a 10% increase in engine volume would lead to ~10% (Usually slightly less, but you get the idea) increase in torque.

01/26/2017 - 20:02 |
6 | 0
Markus Walker

Greatest car with stroker of them all

01/26/2017 - 20:14 |
18 | 2
Dat Incredible Chadkake

Engine Masters did a test recently to see whay kind of power a stroker kit can give you over a stock engine

01/26/2017 - 20:48 |
6 | 0
WouterJS

If you are interested in the dyno figures between a 360CI and a 410CI engine, then watch this video. https://youtu.be/vPBs_QB6ubI

01/27/2017 - 00:06 |
4 | 0
Anonymous

In reply to by Anonymous (not verified)

Video from Engine masters Stroker versus Stocker

01/27/2017 - 09:00 |
0 | 0
Spootneo

i also got the same thing: from 1380 to 1460 cc

01/30/2017 - 08:05 |
0 | 0
Anonymous

Great! I wonder if you use a robust engine oil with a powerful Moly-Graphene based oil additive like the Everglide EGS to boost mpg. Intense!

04/18/2017 - 17:16 |
0 | 0
Anonymous

Car Throttle is dead. Long live they recycling.

04/24/2022 - 15:04 |
2 | 0