Picked up my engine today and see there's a stamped mark on the cylinder head that looks like it was added after it left the factory.

It's a Caterham Supersport engine which has allegedly passed through the hands of Minster Engines.

The stamp is 'CMR 48'. Does this mean anything to anyone?

Cheers

Caterham Minster Racing number 48 maybe?

If it went through minister (now bankrupt) it may have been a megagrad engine..... So it may have forged pistons....
Don,t know about the markings, but if it was originally supplied by Caterham they'll probably be able to tell you the car that is originally came from.
Cheers
Ian

The problem with Caterham records is that they only seem to date back to about 2008 - this engine is going to be from a millenium car (ish) and as such they won't be able to tell you diddly squat.
Normally, the engine number has the same number as the chassis so in theory you should be able to track it back (don't hold your breath)

I called them about the original colour of my car and because its a 2001, I didn't stand a chance.

I spoke to Sandra (I think that was her name) in spares at Caterham and she was really helpful, but she's only as good as her system.

Kind of you to find out all this info Scootz. The new owner of this engine will appreciate all the efforts you've made!

Harsh... but fair!