ENGINE DATING
How to read date codes cast into the side of the block
aquestion that I am quite often asked is “How can I tell when my Land Rover engine was made?”. Usually the questioner is wanting to ship a vehicle to a country such as the United States, where the engine has to be over a certain age to qualify for exemption from various emissions laws. Each engine has its own serial number, but without access to factory production records this can only give you a very rough idea of its age. However, most four-cylinder engines can be fairly accurately dated by reference to the date code cast into the side of the block. I am not sure exactly when Solihull started using these codes, but I believe that all engines built since the early 1970s have them. The date code is usually to be found between the two core plugs on the left (manifold) side of the block as shown in the picture. However, on some older engines I have seen it lower down and further forward.
The code is easy to decipher. The first one or two numbers are the day (1-31), the letter is the month (A=january, B=february and so on – I is not used), the last digit is the year, on a ten year cycle. So 1 could be 1971, 1981, 1991 or 2001. However the type of engine you are looking at should allow you to pin down the year. For example, 200Tdi engines were only made between 1989 and 1994, so a 200Tdi with a date code ending in 2 has to have been made in 1992, not 1982 or 2002. The code gives you the date the block was cast, the actual engine build probably being a couple of weeks later.
There are date codes elsewhere on these engines: cylinder heads are dated (although Tdi heads use a four digit week/year code, so 48/92 would be week 48, 1992) and other major castings, as well as some ancillaries such as turbochargers, may also bear the date of manufacture in some form. I have not yet had the chance to examine a Land Rover V8 engine for date codes, but it would not surprise me at all if they use a similar system. Back in the Series I days absolutely everything was stamped with the date of manufacture, from wheels to wiper motors. I was once contacted by a chap who was looking for wheels stamped with a particular month and year for his concours SI restoration: sadly I was unable to help.