The Chev "Iron Duke"

At first, I thought that the Chev 2.5 was the engine called the "Iron Duke". But the Chev 2.5 (153 cubic inches, 3.875 inch bore, 3.25 inch stroke) is a completely different engine than the "Iron Duke", which is the GM (Pontiac Fiero) 2.5 (151 cubic inches, 4 inch bore, 3 inch stroke) engine (see the Land Rover FAQ for a guide on fitting one of these).

You will find the following text on http://www.wagoneers.com/JEEPS/tech/jeep-engines.txt

> 151 (2.5L) GM I4: Base engine used in 80-83 CJ-5s and CJ-7s.  Called the
> "Iron Duke" by GM in this era, it was re-issued the "Hurricane" name by Jeep
> and was originally the 4 cyl offered in Chevy II's in the 60's and was
> originally derived from the famous Chevy "Stovebolt" I-6 family.

"The 153 was the base engine in Chevy II's in '63-69. It is from
the GM 6 cyl. family 153, 181, 194, 230, 250, 292. It is not the
Iron Duke!! The basic 153 has about 90 hp; this is not a whole lot
more than an F-head. However the F-head has one major flaw; it
cannot rev above 3200RPM and survive for any length of time. Most
end up with thrown rods because some unknowing soul tried to keep
up with freeway traffic. They weren't designed to be driven above
50 mph, and even with an overdrive they don't have the power for
that kind of use. The Chev is quite happy buzzing along at 3000
all day long. With 5.38 gears and a Warn OD and 31" tires you
should be running about 2400rpms at 65mph."
*snip*
"I have seen no less than 25 flatfender Jeeps with these small Chevy
enginesin them, so its a very do-able project. The way you tell one
of these engines from an Iron Duke is the valve cover, which is
rectangular with round corners; the ID's valve cover has about
15-16 facets. 153's came in Chevy II's from '63-69 and in Postal
Jeeps '67-71. All parts from the front and back of the engines --
water, alternators, bellhousings, clutches, etc. -- interchange with
all Chev 6 cyl. except 292. Good Luck." 

On top of this, AMC bought the GM design and used it from 1980-1983. But there's also an AMC 2.5L (150 cubic inches, 3.875 inch bore, 3.188 inch stroke).

In South Africa, the 153 (2.5L 4 cyl), 230 (3.8L 6 cyl) and 250 (4.1L 6 cyl) are well known. The Nomad (2WD Jeepish pickup) and Chev 2500 both used the 4 cylinder engine. (As an aside, the 2.5 was also used in the Eland Armoured Car).

Back to Wouter's Chev 2.5 page (This page last modified 2002-12-04)