Harley Davidson Ironhead V-Twin Engine Overview

In continuation of our series on Harley Davidson Engines — The V-Twin Ironhead.  Hit the jump for background and which motorcycles it was featured on.

Photograph courtesy of the Harley-Davidson Motor Company Archives. Copyright Harley Davidson.

The Harley Davidson Ironhead V-Twin was a 45 cubic inch, push-rod
operated engine (named for its characteristic iron rocker boxes) with
two valves on each of its cylinders. The Ironhead was used on the X
model Harley Davidson Sportster bike from 1957 to 1985. Harley marketed
a 900 cc version of this engine that was supplanted by a 1000 cc
Ironhead engine with overhead valves and cast iron heads by 1972. In
1984 the Harley Davidson Evolution engine arrived and took the place of
the Ironhead engine on Harley Davidson Sportsters.

The Ironhead engine has been used on a number of different Sportster
models and was used as a racing engine on a number of different bikes.
These motorcycles include the XR 750 (750 cc), which was available in
two different versions. The first version was an overhead valve engine
with iron heads that was available from 1970-1971, the second was an
overhead valve engine with alloy heads that was available from
1972-1985. Harley Davidson also marketed the CL CR Sportster (1000 cc
Cafe Racer) from 1977-1978, XR 1000 from 1983 to 1984, and an XLR (883
cc) race bike version with overhead valves.

Harley Davidson Sportster Models (1957-1985)

• XL
• XLH
• XLC
• XLCH
• XLR
• XLRTT
• XR
• XLT
• XLCR
• XLS
• XLS-61
• XR-1000