Engine Serial Numbers

[MikeSimon]

Something piqued my interest when I took a look at the data card for my 280SL. The car is a November 1970 production. It is a LH drive with Auto tranny, thus the two digits between the engine type no and serial number are "12". The engine serial number is 15405. Knowing that just shy of 24,000 280SLs were produced, and AT and MT tranny cars had separate engine number sequences, we have to assume that there was a significant number more ATs than MTs. So far so good. The question I have now, how about the RHD cars? Are the "22" and "20" numbers in the same sequence as the "12" and "10" cars respectively? Anybody?

[BobH]

Hello, i may be a bit dim, but i'm not sure i understand the question

If it helps, my 1965 UK registered RHD Automatic has engine number 127981 22 001816

[DavidAPease]

Hi, Mike,

This doesn't answer your question, but I think it's another interesting data point:

My car is a '66 230SL, number 15461 (out of just under 20,000), so a fairly late car.  It is an automatic (middle digits "12" like yours), and it is only engine number 003868 (taken from the data card).  So the mix of manuals to automatics must have been very different for the 230s and the 280s.

           -David

[rwmastel]

Mike,

If I understand the numbering process I think it is true that engines 12-000001 and 12-000002 would have been built next to each other on the line, but could have been built weeks before engine 10-000001.

Are you asking if the six digit sequence was also unique for LHD/RHD?  Asking another way, are there 4 unique series of engine numbers from -000001 to the end?
From 10-000001 to the end of LHD Manual production
From 12-000001 to the end of LHD Auto production
From 20-000001 to the end of RHD Manual production
From 22-000001 to the end of RHD Auto production

I'm not sure who wrote it, but in the Tech Manual, the answer is no.  Only unique series of serial numbers per transmission type.  Probably due to difference in how these transmissions mounted to the engines?  I guess they didn't care to what global market the engine/car were going.

[Benz Dr.]

The first 700 230SL's were all standards. Of the 1,465 230SL's built in 1963, only a few were autos. I rebuilt a 1963 engine once, which was around 1,100 VIN, but the engine serial number was around 00068 which means they had auto trans engines built well before they came off of the line. 

[MikeSimon]

Mike,

 .

Are you asking if the six digit sequence was also unique for LHD/RHD?  Asking another way, are there 4 unique series of engine numbers from -000001 to the end?
From 10-000001 to the end of LHD Manual production
From 12-000001 to the end of LHD Auto production
From 20-000001 to the end of RHD Manual production
From 22-000001 to the end of RHD Auto production

I'm not sure who wrote it, but in the Tech Manual, the answer is no.  Only unique series of serial numbers per transmission type.   

Thanks! that is exactly what I was asking. I had looked at the Tech manual but could not find an answer. sometimes it is hard to sift through all the old saved comments.

[Mike Hughes]

A casual scan of the 230SLs in our vehicle registry database that were produced around the same time my car (113042-12-015466) was produced reveals that the manual transmission cars (113042-10) with 127.981 10 engines had a unique engine numbering sequence that differed from the engine numbering sequence of the automatic transmission cars (113042-12) with 127.981 12 engines.  Each numbering sequence appeared to ascend from a theoretical 000001.  Since many more manual transmission 230SLs had been produced than Automatics by early 1966, when the chassis numbering sequence of both 113042-10 and 113042-12 vehicles had reached the 15,000s, the engine numbering sequence of the 127.981 10 manual transmission engines was in the 12,000s, while the numbering sequence of the 127.081 12 automatic transmission engines was only in the high 3000s to low 4000s.

Looking at the RHD manual (113042-20) and automatic (113042-22) cars reveals that the 127.981 10 and 127.981 20 manual transmission engines appeared to share the same unique engine numbering sequence, just as the 127.981 12 and 127.981 22 automatic transmission engines appeared to share the same unique engine numbering sequence.

[MikeSimon]

Mike:

I was aware of the fact that LHD with MT and AT transmissions had separate engine number sequences. If you order a head gasket for a 280SL, you will find that the cut-off serial number for the change from square to oval is different for MT and AT.  It is a little confusing, but my question was if the RHD cars fell into the same sequences or whether they had their own. It seems like, they do not.

[jKrashnburn]

The engine number on my '69 280SL (VIN 1130441201142) is 130 983 12 007238. It is a 280 SE/A block.

From the Technical Manual I understand that the "983" designation is for 280SL engines however the Manual also indicates that a 280SE block is the designation for sedan engines.
There would seem to be a contradiction here - or am I missing something?

Also, the Manual includes specifications for the 280 SE/8 engine but nothing on the 280 SE/A. Where can information on the 280SE/A be found?

Any clarification will be very much appreciated. I'd really like to know what I have under my hood/bonnet.

[rwmastel]

The engine number on my '69 280SL (VIN 1130441201142)

That's not enough digits for a VIN.  113044-12-01142 is missing a digit in the final set of numbers.

The engine number ... is 130 983 12 007238. It is a 280 SE/A block.

When you say, "280 SE/A block", is there something specifically on the block that says that?  Or, is it on the cylinder head?

Pics help a lot in these discussions.

[jKrashnburn]

Thanks for responding Rod….yes- last digits of VIN should be 001142 and yes 280SE/A is on the cylinder head. (I’m learning!)
Hopefully these pics will clarify my situation.

[jKrashnburn]

….and another photo

[Pawel66]

I think these markings on the cylinder head are not necessarily indicate an engine for a sedan. You would need to find compression ratio, but SE markings were good for an SL, take a look here: https://www.sl113.org/wiki/Engine/CylinderHead

What I see on your engine is that the engine number stamped on the block does not look like factory stamped number. Do you have "Tauschagregat" plate on your engine?

[MikeSimon]

The casting ID 280SE/A is one of the correct head versions for a 280SL. It is only the head! And the "983" in the engine serial number identifies a 280SL motor.

[rwmastel]

What I see on your engine is that the engine number stamped on the block does not look like factory stamped number. Do you have "Tauschagregat" plate on your engine?

See here:  https://www.sl113.org/wiki/DataCard/EngineNumber