Help me identify my engine and diff.

[M3This]

Hi Guys,

 

Since pulling my car apart I have found a handful of things I noticed are non original with car. For example the passenger door is purple under the door panel, I have a 1pc dash with the wood trim gauge cluster which according what I read online was for square light cars (mines a 1970), also the front brakes where converted to single brake line units so Im wondering what else has been changed over the year.

 

Below is a photo of the engine vin:

 

but the VIN on my car is: 1672270 .... so Im guessing this isn't the factory motor? Anything you can tell me about the motor?

 

A couple of more photos:

 

 

And here is the rear diff, Is this just the standard stock rear diff?

 

 

Any feedback is welcomed!

 

 

[halboyles]

Take two more pics, one of each side of the differential to help with ID'ing.  The top might also indicate a production date.

[7502]

Think I see a thermo reactor exhaust manifold, or most of it. 

[Son of Marty]

The engine vin is from a 1972 02 I belive, looks like a standard 4 speed, the casting numbers you posted of the diff don't provide any real imformation look for hand stamped number/letters on the drivers side of the diff.

[2002iii]

1 hour ago, 7502 said:

Think I see a thermo reactor exhaust manifold, or most of it. 

Nope looks like a regular manifold to me.

 

If you look between the 3rd and 4th intake runners on the head you should see a year along with the head code above, Probably 72 and 121. More on engine identification Here.

 

Definitely a stock 4 speed probably from the same car the engine came from.

 

Looks like 4 bolt side cases on the differential so probably a 3.64 ratio from a 2002.

[M3This]

3 hours ago, halboyles said:

Take two more pics, one of each side of the differential to help with ID'ing.  The top might also indicate a production date.

 

Here you go. Still a lot of crap on it that needs to be scraped off:

 

 

 

[M3This]

1 hour ago, 7502 said:

Think I see a thermo reactor exhaust manifold, or most of it. 

 

Heres the Exhaust Manifold:

 

And some markings on the block below it:

 

[halboyles]

If you wire-brush the dirt off just above the two mounting bolt holes on the driver's side of the diff, you'll discover some numbers that will tell you the gear ratio.  

[M3This]

39 minutes ago, 2002iii said:

Nope looks like a regular manifold to me.

 

If you look between the 3rd and 4th intake runners on the head you should see a year along with the head code above, Probably 72 and 121. More on engine identification Here.

 

Definitely a stock 4 speed probably from the same car the engine came from.

 

Looks like 4 bolt side cases on the differential so probably a 3.64 ratio from a 2002.

looks like your right and it’s a 72:

 

do you think someone just swapped the motor later on in life or this was done by BMW?

[M3This]

19 minutes ago, halboyles said:

If you wire-brush the dirt off just above the two mounting bolt holes on the driver's side of the diff, you'll discover some numbers that will tell you the gear ratio.  

these are the only numbers I could find on either side. 

[halboyles]

40/11=3.64 ratio

[M3This]

Thank you for the help!

[Mike Self]

2 hours ago, Son of Marty said:

The engine vin is from a 1972 02 I believe,

Yep, a fairly late 72 at that.  '73 VINs began with 2585138. It has an E12 head, so came with a two barrel carb.  Definitely a transplant from a later car.  Both VINs are US spec cars; if that was a factory rebuilt engine, it would have a totally different motor number.  

 

And FYI, the stamped 11 40 on the differential casing is the number of teeth on the pinion and ring gears respectively.  Dividing 40 by 11 gives you 3.6363636--i.e. 3.64, the standard differential ratio on US spec 2002s.

 

cheers

mike

[Conserv]

Summing up what others have already said, the engine block was cast on June 7, 1972 (“7F” within the raised oval frame and “72” just outside the frame). VIN 2584028, the original chassis for this engine, was probably manufactured in July 1972. BMW Group Archives (info.grouparchiv@bmwgroup.com) can confirm the manufacturing date of both 2584028 and 1672270 when the Archives reopens for public inquiries later this year.

 

The type E12 head was cast June 1972 (6 nubs surrounding “72”). The E12 head was just being introduced in late spring/ early summer of 1972, replacing the type 121. If you’re rebuilding the engine and installing new pistons, bear in mind that you’ll need pistons designed for E12 heads (piano top), which are different from the pistons designed for the preceding type 121 heads (bathtub top).

 

Given the proximity of the block and head casting dates, I believe that both components started life together, as engine number 2584028.

 

Here’s a point of reference for engine identification.

 

 

Regards,

 

Steve

 

 

 

[Conserv]

10 hours ago, M3This said:

these are the only numbers I could find on either side. 

I cannot see any casting dates on the top of the housing, but perhaps you can double check that or provide a photo. Below is the E21 diff currently in my ‘76. That’s an April 26, 1978 casting date on the top of the housing (“26478”) and a May 1978 manufacturing date stamped into the front left flank (“5” over “8”), just below the numbers of pinion and ring teeth.

 

Both casting dates and stamped identifications on differentials vary, considerably. Yours may well only have the numbers of teeth. But yours is a short-neck differential with four-bolt sides covers, the style manufactured from January 1969 until approximately August 1978. Barring additional information — and noting no evidence of the differential having been cleaned for service or transfer within the last 100,000 miles ? — I’d guess it might be original to your car. The rear cover — without “cooling fins” — is the style used on ‘02 short-neck differentials from January 1969 through August 1973, but these are easily swapped with the later finned style; the buildup of grease on yours, however, appears consistent with the remainder of the differential.

 

Regards,

 

Steve