Morris Minor Owners Club

I have acquired a 1275cc MG midget engine which I am going to install in the mog but the block has no engine number, Will I be able to pass an MOT, is it legal to have an engine with no number? I could just swap the one from the 1098cc engine I have at the moment.

Picky

its illegal to swap the engine no.

its not an uncommon phenomenon, if the block is skimmed or is bored out the engine no has to be taken off to fit the block in the rig and they aren't always put back.

I wouldn't worry about it tbh

Make up any old number you wish! To use the 1098 number would suggest you are trying to hide the capacity increase - but if you declare the new capacity to DVLA (and insurance) then you are doing nothing wrong. MOT only checks Chassis Number - they couldn't care less about the engine number since the car doesn't need emissions test because of it's age. MOT only refers to engine number when emissions test is to be based on the engine rather than the car's age. For example - a 5 year old Mini fitted with a 40 year old engine (number!) qualifies for emissions test relative to that engine, not to the age of the car. Of course the tester needs to be 'convinced' of that - hence they need to check the engine number as evidence of engine age. Strangely enough - a 40 year old Mini fitted with a 5 year old engine - gets away with the emissions test for a 40 year old car!!