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MG MGA - Engine Block Codes

Does anyone out there know any old factory engine branch workers who may know the answer to this problem?

Many Twin Cam engines have lost their alloy tag numbers, sometimes due to the block being caustic bathed at engine rebuild time.

We have about 60 block numbers on record but they don't appear to follow any pattern, here is an extract sorted by engine tag number:

Main-cap Batch/Year ?code Engine#

A1867 11 34 59 E T 16GB/U/1589

A1833 10 99 59 E T 16GB/U/1610

A1748 11 23 59 E T 16GB/U/1611

A1769 10 14 59 E 16GB/U/1613

A1739 9 95 59 E T 16GB/U/1662

We have no idea what the code (E T) is.

These are obviously of twin cam engines but the same is probably true on pushrod blocks.

Anyone know how to crack this code?


Mark Hester

This is the first column the Main Cap Code

Mark Hester

You might send a query to Kent Prather (Prather Racing). He quite an expert on TC engines.

G T Foster

Extended Tappets?

See Neil Cairns document and this section:

"At engine 1587 cast iron tappet bore liners were introduced, due to the buckets picking up on the original aluminium bores. These liners were secured by a grub-screw. MG had some fun with the tappets themselves, as the original 1 1/4" long version could tilt in their bores at high rpm, and locking up. This broke the camshaft, then leading to a blown up engine! From engine number 1087 they were lengthened to 1 1/2" long."

Some MGB engines carried the same lettering. There is a thread on the MGB site.

Steve Gyles

This thread was discussed on 27/08/2010

MG MGA index

This thread is from the archive. The Live MG MGA BBS is active now.