124" Harley Replacement Engine from S&S - 1999-2006

Call 800-841-STAR or E-mail for more information.

(Not available for 99-06 Softails)

S&S offers a truly complete 124” engine to replace 1999-2006 stock Big Twin engines, except for the 2006 Dyna models.

S&S T124 engines are available in silver powdercoat, wrinkle black and now the New Black Edition.

Match the original engine in your bike or go for a custom look.

A lot of riders have already invested in performance upgrades for their stock engine by the time they are ready to move up to a complete big inch engine. Wouldn’t it be nice to be able to save some money by using some of those items on your new engine? Well now you can!

Star Power is now offering S&S Cycle T-Series engines for 1999-’06 big twins without fuel or ignition systems. So if you have already added a performance carburetor or an EFI throttle body and tuner to your stock engine, you can use it on your new engine. A carb or throttle body that fits a stock engine will fit the new S&S engine because the heads are specially machined to compensate for the increased cylinder length so a stock length manifold will fit. If you’ve installed a performance ignition or EFI tuner, you can use it.

S&S is also introducing the T124LC engine, which has slightly lower compression and a shorter duration cam set. This engine is ideal for heavy vehicles like fully loaded baggers and trikes. Lower compression makes the T124LC more resistant to knock and detonation, and promotes better engine life and dependability.



  • T124 - 124 cubic inches, hot-rod performance, 640 Easy Start Cams

  • T124LC - 124 cubic inches with slightly lower compression, 585 Easy Start Cams

S&S T-Series Long Block engines don't come with a fuel or ignition system.

Perfect for riders who already have a high performance ignition and carb or EFI throttle body and tuner.

Since the heads are specially machined to fit a stock length manifold and breathing system, an air cleaner, carb, or throttle body that fit a stock engine will fit your new S&S engine!


Note: If a different exhaust or intake system is used, the fuel maps must be modified.

It is highly recommended by S&S Cycle that this tuning be done by a certified S&S VFI tuning center like Star Power

Features and Benefits

  • No fuel system or ignition systems included - Use what you already have 

  • Special Head machining – Fits stock length intake manifolds (S&S manifold size 410)

  • Stock style breathing system – stock breather spacing and function is compatible with
    stock and most performance air cleaners

  • Same quality components and performance as our complete T-Series engine

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*Notice: This engine is FACTORY ASSEMBLED. Some of our competitors, especially on eBay, offer engines that are self assembled from spare parts at a lower price. Do not take a risk on a non-factory assembled engine!

Notes on Engine Management and Fuel Systems:

Cylinder heads on bare bones T-Series engines are 1999-’05 style. Owners of 2006 models will need to purchase a set of 1999-’05 style, offset intake flanges such as S&S 106-3516.

Cylinder heads on these engines are specially machined to compensate for the non-stock cylinder length. As a result, they are compatible with manifolds and throttle bodies with stock length intake runners. In addition, the breather vent bolt locations have been adjusted so they are in the stock location, so stock style air cleaner back plates will bolt up to these engines.

1999-’01 EFI engines equipped with Magneti Marelli fuel injection will require a performance tuning module such as the DynoJet® Power Commander® 3 or S&S VFI module. The stock duel-bore EFI throttle body is not adequate for T111 or T124 engines. The S&S 58mm EFI single bore throttle body is highly recommended to achieve maximum performance.

2002-’06 EFI engines equipped with Delphi® fuel injection will require a performance tuner such as the DynoJet Power Vision® tuner, Harley-Davidson® Race Tuner, or S&S VFI module. The stock single bore throttle body cannot supply adequate air for these large displacement engines. An S&S 58mm throttle body is highly recommended for maximum performance.

Carbureted engines will require a performance ignition module that allows adjustments to the advance curves. The stock ignition module is not adjustable, and use of the stock module will likely result in engine damage due to knock from incorrect ignition timing.

Performance carburetors are recommended to achieve maximum performance. S&S Super E carbs are ideal for T111 engines in touring applications, but a Super G will produce more top end horsepower. S&S Super G carbs are recommended for T111 engines in performance applications, and for T124 engines in all applications.