Fitting a Chev 2.5 engine to a Series Land-Rover


The Chev 2.5 engine is fairly close to the Land-Rover 2.25 engine in power output, size and weight. So why go to the trouble of replacing the stock, extremely tough LR engine with something else?

Different "Chev 2.5" Engines

I found that there's some confusion about the Chev 2.5 and the "Iron Duke", which are completely different engines. I also found, the hard way, that there are various flavours of the Chev 2.5 engine, with different seals, different compression ratios, and probably a few differences that I have yet to find. So, here's my attempt at The Definitive Chev 2.5 Page.


If you're interested in the nitty gritty of the overhaul, go here. Summary: it cost me R5733.08 + (my) labour, in 2000. Worth it, I think.

2002-11-14: I'm overhauling another engine. Parts are about 50% more expensive.

Fitting the Chev 2.5

OK, so I was under the impression that it would be a fairly easy drop-in replacement. Well, it's fairly easy, compared to some conversions I have seen, but not quite trivial.

Modification to the chassis

The oil filter and the righthand side engine mount outrigger are in the same place. I suppose I could have fitted a remote oil filter, but I decided to cut off the mount and to have a new mount manufactured and welded to the rear of the existing mount.

Engine mounts

I had two plates made up to adapt the Land-Rover engine mounts to the Chev engine. The first ones were of 3mm steel plate, these bent during the Y2K trip, so I made new ones using 10mm steel (overkill? Indeed!).

You also need four 3/8" dia studs, about 2" long, with UNC thread on the one side and UNF on the other. Locktite these into the block, and fit the plates using hi-tensile nuts and lock washers.

Interference between adaptor plate and chassis

When I first started the engine there was an incredible vibration. Eventually traced it to the adaptor plate hitting the chassis. Fixed the problem with an angle grinder, took off a fairly large piece of the adaptor plate.

Clutch spacer

Important! I used an old but good clutch plate I had lying around. All was fine. I had to fit a new clutch in Messina (Read the Y2K writeup for details) and then a problem surfaced. You need a 12mm spacer between the release bearing and the pressure plate. At least, I think 12mm is the right size, it works for me for now.

Running in, how NOT to do it

As always, I finished working on the Land-Rover at 13:00, and we left to go on the Y2K tour at 15:00, with less than 100kms on the brand new engine. Not recommended. At all.


The engine behaved really well, some teething problems, but we travelled a lot faster than we would have done with the stock 2 1/4. I must admit, I really missed the 2 1/4's low down torque in the thick sand at Tsodillo Hills in Botswana, but OTOH we were able to leave Ai-Ais the morning and reach Bellville (about 800km) just after sunset the same day, something my 2 1/4 would not have been capable of.


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(This page last modified 2005-04-29)