Whats the difference between 320i and 325i

[springh]

New to the E30 stuff, just trying to work out- other than the CC difference what other differences are there between the 320i and the 325i? are things like the manifold different? I have a 320i and im trying to get the most out of the engine...

[StuBeeDoo]

Hi Springh, welcome to the 'Zone.
The 'head is different on the '25, as are the inlet manifold and the throttle body. To put it politely, the '25 head (881 casting) can be a bit fragile, shall we say. The 'heads are not interchangable, as the '25 uses different pistons.
Quite a few people (I'm not one of them - yet) have fitted '25 throttle bodies to '20's, with amazingly good results. There are two ways of doing this:
Modify the '20 manifold to take the '25 TB.
Or...........
Port the '20 'head so that the '25 manifold can be used.
If you take the first option, the job's easier and the mid-range power gains are better. The '25 manifold option sacrifices a bit of mid-range gain, but gives even better top-end.
If you use a modified chip too, the gains are even better.
HTH
Stuart.

[320Touring]

differences are....

40bhp more in the 325

better noise from the 320 (smaller bores )

Head design -320 is a 'flahead'=combustion chamber is horizontal at the top, 325 is 'hemi'= like half a sphere

the 325 also sometimes suffers from porous heads/cracked heads due to the fact that the water channels are closer to the chambers

[StuBeeDoo]

the 325 also sometimes suffers from porous heads/cracked heads due to the fact that the water channels are closer to the chambers

I avoided saying that, 'coz some Zoners will get offended!!!

[Karan]

325 has rear discs... i dont think 320s have rear discs....

[StuBeeDoo]

325 has rear discs... i dont think 320s have rear discs....

Good point Karan! I suppose that if Springh wants to go better, he'll need to stop too.
Not a problem for me and Neil 'coz Tourings have rear discs.

[Geeman]

Unless it's a convertible, then they have rear discs...

[StuBeeDoo]

Unless it's a convertible

Oh yeah! Them too.

[Chaos]

2.5 has an oil cooler behind the bumper i dont think the 2.0 has that

[320Touring]

2.5 has an oil cooler behind the bumper i dont think the 2.0 has that

nice one Chaos-always forget about that one....

but was it not an optional extra????

[Chaos]

2.5 has an oil cooler behind the bumper i dont think the 2.0 has that

nice one Chaos-always forget about that one....

but was it not an optional extra????

not sure m8, def standard on 2,5 but dunno if it was optional for the 2.0.
wud be a nice addition tho to a 2.0 i reckon.
help keep everything cool

[Simon]

2.5 has an oil cooler behind the bumper i dont think the 2.0 has that

nice one Chaos-always forget about that one....

but was it not an optional extra????

Not optional, standard on all 325i.

There was a thread on the old zone about fitting the coolers to the 2.0's, but it was deemed totally un-neccesary.

[320Touring]

2.5 has an oil cooler behind the bumper i dont think the 2.0 has that

nice one Chaos-always forget about that one....

but was it not an optional extra????

Not optional, standard on all 325i.

There was a thread on the old zone about fitting the coolers to the 2.0's, but it was deemed totally un-neccesary.

thanks for clearing that up Simon!!!

and nice thinking Chaos

[Simon13]

325's don't really need oil coolers. Mike Australia does not have one on his 325 cab and his don't over heat in 45 C!

[dazleeds]

325 has rear discs... i dont think 320s have rear discs....

my h plate 320ise has rear discs as standard