Engine block # decoding

[mxl556]

Hi all,

Does anyone know how/where to decode 8 digit engine block number (1981 320i)? I found basic info on what each number means (model, serial # of block, factory of mfg and the day of manufacturing) but I am wondering if there is a way to get more information. It would be helpful to figure out the exact manufacturing date (to see if it matches mfg date of my car) or hopefully find out the VIN # of the car the engine in question was installed originally. If you can help, please PM me.

Thanks,
Max

[captain awesome]

I'm curious about this myself. I've read a couple threads on these, and they don't match up with the numbers on my e30 m10 block. Maybe e21 blocks are different coding? I'm told it's from an 84 318i but would be nice to confirm.

[mxl556]

Mine is 01102624...

[cgifool]

This page has the PDF you seek.. I tried to upload it directly but got an error 1 mb file size limit exceeded.

http://www.rtsauto.com/bmw-engine-an...ication-codes/

EDIT: woops, after reading it again, its interesting, but not what you were asking for

[mxl556]

Thanks, interesting PDF, I have not seen it before.


Max

[LemansBlau]

I don't think there's any more information that what you already know. I tried to research this a while ago but got nowhere. In my case, my engine has an April build date but my car was assembled in December. So is it the original engine? Did BMW have 7 months of engines in inventory in 1982? Unlikely I would think.

Also, given that the serial number of the block is only three digits and there's no year identification, it's totally plausible that there could be two different engines with the same block number, manufactured years apart.

[mxl556]

How do you know if your engine has an April build date? Also, the date on the block is the day when this block was made, it does not necessary mean that the final assembly of the engine would happen on the same day.
Serial number of the block is three digits, but there is also a day of manufacturing, which I do not think will repeat. I do not see how two engines will end up with the same number...

Max

[Layne]

If you could get the production date, it's impossible that it could match your car. 8 months previous sounds right to me. The engine making process is very lengthy, and they are shipped and stored before making it into cars. Prior to 1980, the engine number was the VIN. Which means it had to have been stamped at the time of installation into the car. It's practically impossible that an engine could be dedicated to a car from the moment it's cast, probably months before the car was even ordered. This probably created problems with not being able to tell the unnumbered engines apart, and is why they changed the system.

[mxl556]

Makes sense...
I know that on Euro models engine # matched VIN until sometime in 84-85. For the U.S. it was 1978 based on the BMW bulletin of some kind I found online.

Max

[Layne]

For the U.S. it was 1978 based on the BMW bulletin of some kind I found online.

Couldn't be. I have a 3/79 car with matching numbers.

[mxl556]

Good to know. Means that that pdf I found is not accurate. When I contacted BMW archives in Germany they told me that number on my 81 should match my VIN.
Sounds like nobody really knows for sure.

Max

[LemansBlau]

How do you know if your engine has an April build date? Also, the date on the block is the day when this block was made, it does not necessary mean that the final assembly of the engine would happen on the same day.
Serial number of the block is three digits, but there is also a day of manufacturing, which I do not think will repeat. I do not see how two engines will end up with the same number...

Max

The last three numbers on my block are 101 - April 11th, which was a Sunday in 1982 (no way to tell if it was actually built in 1982 though).

The serial number is three digits so every thousand blocks the number would be used again and the manufacturing day is reused every year. It's unlikely, but totally plausible that there could be two engines with the same number.

[mxl556]

I see what you mean.
I was thinking that the manufacturing day does not get reset every year. Reason being - mine ends in 624 and even considering that the factory operates 7 days a week 365 days a year it does not work... Your being #101 must be built earlier than mine?Hmm.
Is yours the original engine?

Max

[epmedia]

I believe the most important thing to consider is if the engine was assembled on a Friday, or not. This would require some research because leap years and stuff...

[320iAman]

http://www.r3vlimited.com/board/showthread.php?t=72192

"My code is 24376031
The First number stands for the assembly line
0 or 1=M10, M42
2 or 3=M20, M21, M50
4 or 5=M30
6=S14, S38, M70
So since my first digit is 2 my block is an m20

The next 3 numbers is the serial number of the block so mine is serial # 437

The 5th number shows which factory the block was built in
0-4=Munich
5-9=Steyr(Austria)
So my block was made in the Steyr plant

The last 3 digits stand for the production day, so mine was produced on day 31

Now if the engine has been replaced by BMW or rebuilt or if the engine was replaced during production there will be a seperate code stamped up above the engine number, representing the build info like displacement etc..."

Randy

- - - Updated - - -

I see what you mean.
I was thinking that the manufacturing day does not get reset every year. Reason being - mine ends in 624 and even considering that the factory operates 7 days a week 365 days a year it does not work... Your being #101 must be built earlier than mine?Hmm.
Is yours the original engine?

Max

Subtract 365 and match,,, My last 3 is 452,

Note also Made in Munich--Assembly Plant is in Munich, the Blocks were made in a foundry to be more precise, no cast iron steel foundry of this magnitude in Munich Glad or Munich--its a city, The foundry was out in the sticks. The engine was put together in the sticks and shipped to Munich where they installed in the 320i, ect on the assembly line, same for all car manufacturers. The engines come complete, Getrags transmissions come complete and so forth. I talked with the Overall Shift Foreman for all shifts in Munich, he told me that they have over 100 suppliers for certain car parts they assemble there, He is not the first one I have met, I have met a few from GM as well..

Randy

[mxl556]

Randy,

I found the info above in the BMW memo from TIS. So I know what numbers mean.
The question are- when is the 1st day of production of M10B18 block/engine? How many days factory was open?

Thanks,
Max

[Manny G.]

This topic got me digging around for info on mine.

My 01/81 produced (MY81) E21 320i has 03332690 stamped on it.

03332690

0 = M10
333 = Serial
2 = Munich plant?

Now for the part that I cant make sense of...

690 = Production day ? how are there more than 365 days in a production year? I think something is missing here