The Definitive :-) Chev 2.5 Page

I found out a lot about the Chev 2.5 engine, and I will probably find out more, the hard way.

Iron Duke

The Chev 2.5 (153 cubic inch) is not the "Iron Duke".

Differences in Chev 2.5 engines

Sump

I've seen two variations in the shape of the sump, a front sump and a rear sump. The only differences are the oil pump pickup tube and the sump shape.

I went with the rear sump, figuring that keeping the sump away from the front axle is a Good Thing.In practice, the engine actually sits well clear of the front axle, so either sump should work fine in a Land-Rover.

Rear crank seal

Chev 2.5 engines can have either a rope seal or a split elastomer oil seal. I have no idea how to identify which is which without taking the engine apart, but I have the following three engines as data points:

Block casting number 3424165 Serial number 171347CBK Elastomer seal
Block casting number 3424165 Serial number 270631CBF Rope seal 
Block casting number 3427500 Serial number 335862CBF Rope seal

OK, so at this stage it looks as if the basic block casting can be machined to take either seal. Bit of a bummer, if there's no way to tell the type of seal from the outside. Maybe the K in the serial number? If you know, please email me.

Some tips for installing the rear seal.

Compression ratio

71cc on left, 58cc on right.

The first engine I overhauled pinged terribly. I measured the head of another engine, and the head volume was 71cc, which gives a compression ratio of 7.8:1. When I eventually pulled the pinging engine, the head measured 58cc, which gives an 8.9:1 compression ratio. Way high for a Land-Rover.

Head casting number ??? Volume 71cc CR 7.8:1 Head casting number ??? Volume 58cc CR 8.9:1

Back to Wouter's Land-Rover Chev 2.5 conversion page (This page last modified 2004-01-15)