E30 Zone

Guys,

I dunno if this has been asked before, im not that clued up with engines all i know is that 320's and above are 6 cylinders compared to the 316's and above.

I want to know is the following;

What makes a 325 engine different to a 320 if they are both straight 6's?

What components need to be changed on a 320 to perform like a 325?

Do you have to do big engine rebuilds like top and/or bottom ends?

Is it a case of a different ECU?

The reason why im asking is because how do i know im buying a genuine from factory a 325i and its not a 320 with modifications?

The 325 is a totally different engine to the 320. the 320 is 2 litre, the 325 is 2.5. The 325 has a different head - it will have 885 instead of 731 written on the side of it that's probably the easiest way to tell other than looking at the engine number.

There's also differences in the sizes of the front struts, and the 325's have disc brakes on the back instead of drums.

Phil

About 50 of these..............

Im so dumb how did i miss the biggest obvious clue. 2.0 and 2.5

How about with the 323 did they make a 323 in these engines?

yeah, but only in pre-facelift from 1983-85ish...

Only way to convert a 320 to 325 is to rip the motor out; very little is interchangeable on the actual engine, and because of the power outputs they had different gearboxes and differentials which meant a different propshaft too. You can mate a 325 engine to a 320 transmission but the gearing will be very sporty

Also, BMW engines don't take well to "tuning", so bolting on induction kits and fat exhausts will make f-all difference to a 320. So if you want power, don't think about modding a 320; just buy a 325 to start with.

I would go for either a 318is or a 325 which ever mint one i come across first

If its a 320 with a 2.5 lump in it, it will still say 320 on the log book under model name.

also check the vin plate above the headlight (i forget which side it is)

the VIN plate will tell you what car it was from the factory. check the chassis number on the plate and below the windscreen against the V5 to confirm its the correct VIN plate/car. then all you have to do is check if its a 2.0 or 2.5 engine using the methods suggested above.

confused yet