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MG MGB Technical - engine ID

I am at the moment taking the head off of the engine that came out of my 1967 GT, unfurtunatly there is no serial number stamped into the block, the chap that i bought the car from beleives that the car had been fitted with a gold seal replacement engine some time before he baught the car which had been sat in his garage for the last six years, i have heard the engine running and it sounds fine and it is indeed painted gold but anyone could have done that, my problem is how to identify which engine it is, any help would be most welcome, Vin
Vin Rafter

Vin-
If the engine identification plate is missing, there is a way to date the age of the engine block. On the right hand side of the engine block, in the area between distributor and oil filter, there are three numbers that form a circle and that are slightly raised, e.g., 30 12 71, which tells the day, the month, and the year during which it was cast (in this case 30th day of December, 1971). The top one is the day, the left one is the month and the right one is the year. In the early 1970s the month code changed to a letter, thus 12 G 3 would be 12th day of July 1973.
Stephen Strange

I remain to be convinced that it is actually day, month and year. UK companies typically date components by week or fortnight number and year. It's my belief that the letter represents the pattern for the casting, as no doubt there would have been many, and if they started to get casting problems they would want to know which pattern had been used. However I haven't seen enough date marks to confirm that, any examples where the top number is between 32 and 52?

On cars without the emissions kit and the inverted filter at least, they are relatively easy to see.

In any event they seem to have stopped doing it between 73 and 76.

PaulH Solihull

Whilst I would need more details (such as those being discussed) from Vin to be able to answer his specific need, I thought I might add some details on components in my 69 CKD produced roadster as an extension of Paul's discussion of the meaning of the 'date stamp' on MGB blocks.

I have PO files on this car - some 2 inches deep - of paper work from original sale through service over the intervening years prior to coming to me in 2001. Both POs were lawyers which probably explains the propensity to file even the most trivial details. Very helpful all the same and sufficient to convince me that the following details all relate to the original components on the car at time of sale - 12 September 1969.

I understand from Clausager that CKD components were assembled in England at a point in time in batches of I think up to 12. With that in mind some date numbers on components on my car are as follows:

Block casting numbers are 8 above 11 on left and 68 on right - suggesting 8 November 1968

Head casting numbers are 68 to left 10 to right both over 30 - suggesting 30 October 1968

Gearbox casting numbers are 24 10 68 suggesting 24 October 1968

Gearbox reverse switch metal lip numbers are 31824A 10 68 suggesting October 1968

overdrive numbers are 2806 68 D (on LHS of OD case)suggesting 28 June 1968? Or at least 1968?

All of the above would have been part of the assembled batch of CKD components sent out

Electrical components eg coils, distributor, starter motor, were locally supplied but these have numbers consistent with the above date ranges and with the assembly period and sale date of my car viz June 1968 to April 1969. The alternator was changed in 1972 IIRC and bears numbers of 7 70 suggesting July 1970. The starter solonoid was also changed (not surprisingly given age and miles) and has numbers of 3 82 suggesting March 1982.

All of which leads me to conclude that the stamping we are discussing is, in all probability, a date stamp reflecting the production of the block casting.

Not conclusive I acknowledge - but certainly persuasive.

Regards
Roger

R Taylor

This thread was discussed between 17/03/2013 and 19/03/2013

MG MGB Technical index

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