So, I just bought a parts car but it came with a great engine. The car was originally a 1.8 but the guy he bought it from told him it was upgraded to a 2.0. Is there any way I can tell the dif with out pulling it apart?

Also is there a dif between the heat exchangers on aa 2.0 and a 1.8? Can you interchange them?

What about the rest of the exhaust system muf ect? Can you use a 1.8 muf and heat exchangers on a 2.0 engine?

If the car still has the fuel injection a 2.0 will have a large air cleaner right on top of the motor. The 1.8 will have a box hooked off to the drivers side of the car. Also the 2.0 heads will have 3 bolts on the intake manifold.

As far as exhaust, i believe it is all interchangable, but the 2.0 exchangers will requrie a different muffler hanger but otherwise should work with each engine.

Intake system is a good give away, unless it's carbed. The Spark plug angle I think is an easier way to tell.
Do the pulgs point straight(or very close to) up. If you can stand over the car and can see down through the tin to the plug and it's surrounding head, it's a 1.8. If the plug to cockeyed, at about a 45% angle and you'd have to twist and stick you head into the engine compartment from the side to see the plug through the tin hole. You have a 2 liter.

engine number on the top of the case. see the "914 Info" section for correct numbers.

HE's and muffler will interchange as long as you use them (and mounting hardware) together. mixing them won't work ...
Andy