|The MGA With An Attitude
MGA NUMBERS TECH -- BUY-101D
For the MGA 1500 cars, at least through 1958, the original engine number was stamped on the large ID plate along with the Car Number, and the Car Number included a few other things, like the paint color code for the body.
Car No. plate with early style numbers
For later cars the box on the ID plate for the engine number was simply printed with "See Engine", and most of the extra characters in the Car Number may have been left out leaving only a 5-digit serial number for the Car Number (or maybe 6 digits with a leading "1" for the latest production from early 1961 through June 1962).
Engine number plate at top edge of engine block
The engine number, if it still remains, would be found in raised stamped numerals on a small aluminum tag attached to the top corner of the engine block with two drive rivets just below the head gasket between #2 and #3 spark plugs. It is not uncommon for the tag to be missing (and no great crime either). During the machining process for re-boring the cylinders for an engine rebuild the engine block is normally "hot tanked" for cleaning, and this process will dissolve the aluminum tag if it was left on the block. If there is a tag there it is not unusual for it to be somewhat mutilated from the process of removal and re installation, or it might be a spanking new issue created to replace a missing or damaged tag. It is also very common for the engine to be a replacement unit, in which case it should have a different number than the original engine. In the end, only a real concours enthusiast would even care if the engine number was as original. It might be of some concern that the engine should be the original type, as having a 1500 engine in a 1500 car, but even that is of little concern for a daily driver. My 1500 car currently carries a 1600 engine with a cylinder head from an 1800 engine, and I have a 1622 engine under the workbench for a spare. It is usually considered fair game to mix and match these engine parts, except that people don't usually like an engine that is smaller displacement than original, and a fair number might actually object to an MGB 1800 engine in the MGA, even though more would welcome it with open arms.
For the MGA Twin Cam engines, the engine number plate was attached to a horizontal surface on the rear of the engine behind the cylinder block.
In case you find an engine number that does not follow the expected format for an MGA, you can consult a list of B.M.C. & Morris Engine Codes to determine if it may have come from some other model car.
To remove the engine number plate you can grind a slot in the rivet head with an abrasive wheel and unscrew it with a BIG flat blade screwdriver. It helps if you can get a knife blade underneath to assist in lifting while you turn it anti-clockwise. Once it comes up a little you can get it with ViceGrip if needed. I have always been able to unscrew them that way.
On October 21, 2012, Andrew Williams in Launceston, Tasmania, Australia wrote:
"Here's one I prepared earlier. I was surprised how easily the rivets came undone".
Australian built CKD cars had a different Vehicle ID Plate to conform to local law. Here the third line contined the engine number. The engine number was also stamped on the engine, as the factory type riveted plate was not allowed.