The Iron Duke Resource Site


Iron Duke Performance FAQ
Variations in the GM 2.5L
Building a 120hp Duke
A Modest Duke
D.J. Draper on the Duke
Fiero Transmissions

Welcome to my newly redesigned Fiero 2M4 resource site.  The original site recorded over 12000 visits,  hopefully this one will also prove as useful.
Ira Crummey

The Little Engine That Could!

The majority of Pontiac Fieros were built with the cast iron, pushrod, low rpm, 2.5L four cylinder engine.  The Iron Duke or Tech 4, as it was later called, was a simple engine with more potential than most of us realize.  Here is where you can start to appreciate one of the workhorse engines which are all too often ignored and maligned.

This page is not meant to send you out looking for a four cylinder Fiero to build a performance car. The 2.8L V6 Fiero offers far more "Bang for the Buck" since they cost only a little more and have 50% more horsepower. This is aimed more at the owner who wants to try something different, BUT EXPENSIVE, like building an SD4, or someone who already has a 2.5 and would just like to try some of the more modest suggestions to make their cars more enjoyable.

Ira Crummey

General Information about the Pontiac 2.5 (small FAQ list)

Variations in 2.5L Stock Engines

S.J. Wynman on Performance building an Iron Duke (120hp)

Don't Expect too Much!! - Randy Agee on the Limitations of the Iron Duke

D.J. Draper on Building a Reliable 1984 Iron Duke

Fiero Transmissions