The 124 cubic inch T124 low compression Long Block engine fits 1999-'06 HD big twins except 2006 Dyna models. Long Block engines do not include a fuel or ignition system, so they can be used for either carbureted or EFI applications. If you already have a performance ignition, larger carburetor or a larger throttle body and EFI tuner, they can be used with this engine. The cylinder heads are specially machined to compensate for the longer cylinders so a stock length manifold or throttle body will fit perfectly, and the cylinder head breathers are compatible air cleaners designed for a stock engine. Stock non programable engine management systems should not be used because they are not designed for an engine this large. Engine features 4-5/8" stroke X 4-1/8" bore at 10.2:1 compression, S&S 585 Easy Start cams, S&S high flow oil pump and cam cover, and silver powder coat finish that matches stock engine components. This engine has slightly less compression than our high performance T124 engine, making it more tolerent of variations in fuel quality, and a better choice for heavier vehicles. Two year warranty.
Cylinder heads on T-Series long block engines are 1999-’05 style. Owners of 2006 models will need to purchase a set of 1999-’05 style, offset intake flanges such as
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 dual-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 can not 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.
Not legal for sale or use on CA or EPA pollution controlled motorcycles.