The majority of ‘02’s retain their original factory engines. Each car’s original factory engine was stamped with an engine number that matched that car’s VIN. More specifically, the engine’s block was stamped with this engine number or VIN. Thus, even when the VIN and engine number match, you still might want to do some sleuthing to see, for instance, if the engine’s head might be original to the car. One cannot simply assume that an original block will be accompanied by an original head.
And for those cars without their original (matching-number) engines, there is a constant demand to figure out where and/or when the block and head started their lives.
Let’s examine blocks first and heads second.
Engine Numbers or VINs
Each factory-installed block was stamped with the car’s seven-digit VIN. This engine number was stamped into a machined boss at the left rear of the engine — just in front of the bellhousing and just above the rear end of the starter motor (Figure 1, with a red circle identifying the location of the machined boss). The seven-digit engine number was flanked by a pair of “+” signs (Figure 2).
Sending an email to BMW Group Archives, with the VIN and/or engine number, requesting their data on the car, will give you specifics about the engine’s first venue, i.e., the car in which it left the factory — whether or not your engine number matches your car’s VIN. Group Archives’ email address is: firstname.lastname@example.org
The manufacturing date for the car is also approximately the assembly date for the engine.
If you need more information about the car before Group Archives’ reply arrives — generally one or two business days — you can use the VIN decoder offered and operated by the BMW 2002 Car Club of Columbia. It is accurate, but can only provide date ranges for manufacturing dates, with those date ranges often being a full calendar year:
If the car in question is a 1974 model or later — “1974-ish” is probably more appropriate — RealOEM.com can provide data similar to the Car Club’s VIN decoder plus the specific month of the car’s manufacture. You must select “Classic”, not “Current” as the Catalog before entering the car’s VIN.
So, assuming your engine block has a seven-digit engine number, you now understand where this engine block first appeared, in an assembled form, as part of a long block installed in a car.
Block Casting Dates
But each ‘02 block also displays its casting date, cast onto the right side of the block, generally in the vicinity of the first and second freeze plugs (Figure 3, with a red circle identifying the location of casting date).
There are two different styles of casting dates: one incorporates day, month, and year within a raised oval border (DDMYY format); the other incorporates day and month within a raised oval border (DDM format) and leaves year (YY format) outside the oval.
The letter “I” is not used to signify month as it is too similar to the numeral “1”. So months range from “A” (January) to “M” (December). Illustrating the two dating styles, below are blocks cast September 3, 1967 (Figure 4 “3J67” inside raised oval) and December 2, 1971 (Figure 5: “2M” inside raised oval and “71” nearby).
Obviously, the casting date must be the same-month-as or earlier-than the original car’s manufacturing date. But how much earlier can we expect? Most examples I’ve seen range from three months before the car’s manufacturing date through the manufacturing month.
Blocks without Engine Numbers or VIN’s
If you purchased a new replacement block from BMW, it had no engine number. If you purchased a factory exchange engine from BMW — not uncommon — it probably had identification numbers, but not in the form of a seven-digit engine number. Used cores traded in for rebuilding had their original engine numbers ground off at the time of the rebuilding.
All these blocks still provide evidence of their history in the form of casting dates, but only marked exchange engines can provide history beyond the casting date.
Exchange engines were generally marked in one of two locations: on the engine number boss — as described above; or on the rear top ledge of the block, just behind the head. Illustrating the two identification styles are blocks remanufactured November 1983, or 1993? (Figure 6: “113”) and November 1986, or 1976?, or even 1996? (Figure 7: “11 6”).
A Technical Reference Information (T.R.I.) notice dated October 1990 provides a de-coding key for factory exchange (remanufactured) engines produced from 1978 onward. Pages 1, 4, and 6 of this notice (reproduced below as. Figures 8, 9, 10) have the data relevant to this de-coding.
To illustrate, and returning to Figure 6, and its markings (not, technically, stampings):
a. “22 TI US” identifies the basic type of engine, as shown on page six of the T.R.I. of October 1990. It is an engine for a U.S.-spec tii: M10, Part No. 11 00 9 056 520.
b. “0960” is the engine’s new serial number.
c. “A” signifies an exchange engine.
d. “113“ signifies an engine remanufactured in November 1983, possibly. Perhaps unaware that the remanufacturing of engines might extend into the 1990’s, BMW chose to use a single-digit code for the year, leaving plenty of ambiguity as to the date. The casting date of the block or head might eliminate some possible years, and I believe dates from the mid-1970’s through the mid-1980’s are most likely, although certainly not assured.
e. A BMW roundel indicates factory parts or equipment. and
f. “11 00 9 056 520”, a complete part number for the engine, rounds out the data. I believe the appearance of a complete part number represents a later form of the stamping.
Alternatively, and returning to Figure 7, and its stamping:
a. “22 T”, although not shown on the T.R.I., is a turbo engine.
b. “A” signifies an exchange engine.
c. “11 6“ signifies an engine remanufactured in November 1986, possibly. Perhaps unaware that the remanufacturing of engines might extend into the 1990’s, BMW chose to use a single-digit code for the year, leaving plenty of ambiguity as to the date. The casting date of the block or head might eliminate some possible years, and I believe dates from the mid-1970’s through the mid-1980’s are most likely, although not assured.
Between engine blocks stamped with a VIN and engine blocks stamped with remanufacturing data, the vast majority of blocks are largely identified. If you have neither of these, all you really have is the casting date. And note, new replacement blocks were being cast periodically at least through 1987. So even if the block was cast well after the ‘02 era, it can still be an ‘02 block.
Many ‘02’s have their original heads. And many do not. Aluminum heads warped, corroded, cracked, or otherwise failed with greater frequency than the cast iron blocks. But the heads are not “number-matched” like ‘02 blocks, so absolute dead-on proof that X head left the factory on Y block does not exist.
So how do you know if your car’s head is original to the engine? You don’t, at least not conclusively. If the head type is correct for your displacement engine — type 118 for 1.6 and 1.8 liter engines, type 121, E12, or E21 for 2.0 liter engines — and the head’s casting date falls in the car’s manufacturing month, or up to a few months — let’s say four months — before the manufacturing month, it may well be the original head. If the head’s casting date falls after the car’s manufacturing month, it is not the original head. Period!
Both the head type and casting date are cast into the left side of each head. This information is most commonly in the vicinity of the number three and four intake ports, but, particularly on 1960’s head castings, I’ve sometimes seen type and/or casting date closer to the number one intake port. If the cast-in information is not in the “usual spot”, don’t give up: simply expand the scope of your search.
As with engine numbers, the fuel injection runners of tii’s make it difficult to see the head type and casting date on a fully assembled and installed engine.
Illustrating head types and casting dates are a June 1968 (6 nubs surrounding “68”) 121TI head (Figure 11), an October 1971 (10 nubs surrounding “71”) 121 head (Figure 12), and a November 1973 (11 nubs surrounding “73”) E12 head (Figure 13).
As with blocks, replacement heads were produced well after ‘02 production had ceased. I’ve seen ‘02 heads cast as late as 1987. Others may have seen even later examples. Below (Figure 14, 15) is a factory engine having a block cast October 23, 1987 (“23K” within oval frame and “87” nearby) and an E21 2,0 head cast February 1986 (2 nubs surrounding “86”). That’s a late ‘02 engine!
I’m not, at this time, going to discuss the general application dates for the various heads, beyond saying, in most general terms:
1. 121 and 121 TI heads, in 2002’s, November 1967 through mid-1972,
2. E12 heads, in 2002’s, mid-1972 through July 1976, and
3. E21 heads, in 2002’s, September 1975 through July 1976.
This forum has collected lots of information on heads and their applications. But I believe we could use a succinct summary of this voluminous knowledge. How about a volunteer to take on this project? It might outline the date ranges for the various head types, and sub-types, e.g., 121, 121T, 121Ti. It could show valve sizes, compare combustion chamber shapes, etc. Intrigued?
Thanks especially to all of you whose ideas and photographs I may have borrowed to prepare this article!
Thanks and regards,
Edited by Conserv