Engine serial number identification
 

Okay I've done my research but I am unable to determine the second digit in the serial number of an engine I have. It is a type 911/57 case with the serial number 6520151. The digit I cannot figure out is the 5. I know 1 is a T, 2 an E, and 3 is an S, but what does the 5 indicate?
Thank you in advance,
Kevin

Is it possible the 5 is really a 3 or is it definitely a 5?

My source indicates it's a 72 2.2 liter carbed T engine--that's the significance of the 5 in the second position (5=TV, which decodes into T model, V Vergaser-carburetor.) Most likely a European delivery

Upside down 2? They did serve beer at the factory for lunch... :)

As per ossiblue,

E series (1972) 911T called 2.4 liter (2,341 cc) with Zenith 40 Tin carburetors for non US model (911/51 for the US). 1,963 produced.

But the Red Book is not perfect...

To All:
Thanks for the information, and I did verify that it was a 5 not 3 (I questioned that myself). I unfortunately don't have a copy of the red book.
Kevin

After rereading the replys we have conflicting info. The engine is a 1972 which should be a 2.4L but ossiblue states its a 2.2L, any thoughts?

Yes, JJ 911SC, it's a 2.4, not a 2.2 as I mistakenly put. Thanks for the memory jolt.SmileWavy

European T delivered with Zenith carbs,
Bruce

Until you do:

911/57 (non-US 911T). Same as C & D series except:

84mm bore x increase stroke to 70.4 mm
2,341cc
Fully counterweighted crankshaft
Oil jets for piston cooling
Camshafts same as 911/51
Zenith 40 TIN carburetors
7.5:1 compression ratio
130 horsepower @ 5,600 rpm
144 foot-pounds torque @ 4,000

Transmission:

915/12 (4 speeds), or
915/02 (5 speeds)

I agree with JJ. Out of curiosity, what are the "R" codes on the case below the oil tubes?
901.101.101.4R & 901.101.102.3R
or
901.101.101.5R & 901.101.102.4R

Dave
To the best of my knowledge they are just casting numbers.

Matt, yes they are, however I am doing some research into the progression of the "R" codes since the "xR" is basically a revision code. From 1969 through 1973 there was a rapid progression of the codes. Each revision translates into a particular casting change. See my thread here:
911 engine case Revisions

Dave
Wasn't w
Aware of that thread. It has been a while since I cracked it open but I seem to recall a bit of detail about the casting changes in Anderson's high performance handbook.

djpateman,
The "R" codes are as follows:
901 101 102 3R and 901 101 101 4R
type 911/57