2.0 to 2.5 (again)

[koos]

Hi all, wanna drop a 2.5 in my 320i, I know its been asked to death but all the searches i have done are all a bit inconclusive. My 320i is a 1991, what will I need to do the conversion?
1: Can I use the 320 gearbox?
2: Can I use the 320 ECU?
3: Can I use the 320 prop-shaft?
4: Can I use the 320 exhaust (it is twin pipes right through)
5: Will a chrome bumper 325i engine fit?
6: Will a engine from a auto work(will the 320 flywheel and starter fit?)

Any additional info will greatly appreciated.

Many many thanks

Mitch

[Brianmoooore]

Hi all, wanna drop a 2.5 in my 320i, I know its been asked to death but all the searches i have done are all a bit inconclusive. My 320i is a 1991, what will I need to do the conversion?
1: Can I use the 320 gearbox?
2: Can I use the 320 ECU?
3: Can I use the 320 prop-shaft?
4: Can I use the 320 exhaust (it is twin pipes right through)
5: Will a chrome bumper 325i engine fit?
6: Will a engine from a auto work(will the 320 flywheel and starter fit?)

Any additional info will greatly appreciated.

Many many thanks

Mitch

Basically, yes to everything!
1: Has better ratios, but is weaker. Probably won't cause any problems in practice.
2: Same as 325 ECU with a different chip. If you are upgrading to one of Ant's chips, then no problem, otherwise you need to change the chip, so you may as well change the whole ECU.
3: With the 320 gearbox.
4: Yes, pipes are marginarl smaller, so you have to use the whole system.
5: Yes.
6: Auto engine will fit with a spigot bearing fitted. Flywhell, clutch and starter all fit, but 320 clutch is weaker than the 325 clutch. Same applies to the diff.

[johnna]

I have just done this and have a spare (brand spanking new) 325i clutch for sale, cos I bought two and used the first that got to me!

As Brian says, yes to all.

I am over the moon with my conversion!

I had a spare 320i box to bolt up before the old one came out.

PM me if you have an interest in the clutch.

[koos]

Thanks a mil Brian, thats what I wanted to hear. My 320 head is leaking oil (in the front/right) and the clutch shudders, so I reckon a 325i rebuilt will do the job. That is really good news, all I really need is a 325i lump. Gonna strip it down and rebuild it, and when its done, swop it over.

Johnna: How is it with the 320 box? What ratio diff do you have in? I have a 4.1, wanna drop down as it revs a bit high on motorway. Will let you know about the clutch. Whereabouts are you?

Thanks again. Really appreciate it.

Mitch

[johnna]

Hiya Mitch I'm 300 miles north mate! But the clutch will only cost £8 to post. It is on ebay at the mo. They are ~£100 at the cheapest and I'm asking for £70 buy it now plus £8 postage.

http://cgi.ebay.co.uk/ws/eBayISAPI.dll? ... &rd=1&rd=1

The 320i box and diff are fine, yes a little busy on the motorway, but I am sure 125 is easily possible, without hitting the limiter. On a very quiet desolate airstrip, my clocks read 135mph when I was bedding in the chip at higher end speeds.

As for my diff ratio, I dunno, there is no tab on mine and I've never checked it for details.

BTW, my engine came from an auto too and I was hoping it would have been unstressed. I think it has been!

[JohnnyRob]

I'm going to be attempting this sometime this year. I'm on the lookout for a cheap complete accident / rust damaged 325 which I will use as the doner.

is there an idiots guide for the conversion, and how long should it take? I know I'll need a hoist.

I've got a haynes, but was wondering what advice you zoners had after completing the upgrade.