hi folks, ime really struggling to find out how old my rover engine is (20T4GL77 139852) tried rovertec and mg forums, engine was brought brand new and crated from a rover auction so have no car vin number any ideas?

all i can find out is engine made from 92 to 99

if i dont manage to age the motor what emissions cat will i fall in to on sva?

Another Coventry builder eh?
Where are you?
If it is a 92/99 engine it will probably come under emissions testing with a cat.

ime in longford my friend, so what figures are we looking at for emissions then pls??

Have you tried asking HERE

As a rough guide see below.

22 CO emissions (mixture) At the time of writing, for vehicles first used between 1st August 1975 and 31st July 1986 (P to C registration), the CO level must not exceed 4.5% by volume. For vehicles first used between 1st August 1986 and 31st July 1992 (D to J registration), the CO level must not exceed 3.5% by volume. Vehicles first used after 1st August 1992 (K registration) must conform to the manufacturer's specification. The MOT tester has access to a DOT database or emissions handbook, which lists the CO and HC limits for each make and model of vehicle. The CO level is measured with the engine at idle speed, and at "fast idle". The following limits are given as a general guide: At idle speed - CO level no more than 0.5% At "fast idle" (2500 to 3000 rpm) - CO level no more than 0.3% (minimum oil temperature 60ºC) If the CO level cannot be reduced far enough to pass the test (and the fuel and ignition systems are otherwise in good condition) then the carburettor is badly worn, or there is some problem in the fuel injection system or catalytic converter (as applicable).

23 HC emissions With the CO within limits, HC emissions for vehicles first used between 1st August 1975 and 31st July 1992 (P to J registration) must not exceed 1200 ppm. Vehicles first used after 1st August 1992 (K registration) must conform to the manufacturer's specification. The MOT tester has access to a DOT database or emissions handbook, which lists the CO and HC limits for each make and model of vehicle. The HC level is measured with the engine at "fast idle". The following is given as a general guide: At "fast idle" (2500 to 3000 rpm) - HC level no more than 200 ppm (minimum oil temperature 60ºC)
Excessive HC emissions are caused by incomplete combustion, the causes of which can include oil being burnt, mechanical wear and ignition/fuel system malfunction.

Steve