E30 Zone

hi, im a new guy to the bmw world and as i stated in my other thread im not the most intellegent on computers.

can someone tell me if i was to buy an e34 535i can i use the engine tranny and prop on my 1986 325i sport?

what mounts? i could make my own but are they available 2nd hand or new for this conversion?

i apologise for asking what is probably a very common question. i have used the search and read through lots of threads but im confused with all the different variables.

id like to just get a 3.5 in as easy as i can then i can mess around with it making it better afterwards.

this will my 1st bmw conversion so i dont want to cock it up as the car is very clean.

thank you in advance for your help

As I understand it, a 535i manual is the best starting point.

Your E30 diff will be fine if it is the standard 3.64 LSD.

The M30 engine loom plugs into the E30 body loom with two wires swapped around engine loom side.

An electric front mounted fan conversion is required with a non E30 radiator.

Engine mounts are available to buy, from somewhere or someone.

Try and post up here for best advice.

http://www.e30zone.net/modules.php?name ... forum&f=55

cool, thanks for the help.
so does the prop etc just bolt up as normal. ive heard of people making them shorter etc depending on mounting location?

you'll need a M3 prop or a custom one. it needs to be shorter and have a differend gearbox flange on it, the M3 prop fits perfectly.

i've moved this thread to the M30 (that's the engine code) conversion section, you'll get more help there.
have a read through the posts, a lot of us have done it so you'll be able to get a good idea of the work involved.

Right, as you are starting with a 325i thats half the battle done,imo the m30 is just like a big m20

Prop: you can either use an M3 prop,e36 328i prop (centre bearing reversed), custom prop (e30 rear half joined with 535i front half) or you can do what ive done and take the flange of your 325i gearbox put it on the 3.5 box and use the 325i prop as its the perfect length,some say the 325i prop isnt strong enough but mines been running over 7 months now with no issues also the turbo boys throw 300+bhp through an m20 prop with no complaints

Mounts: must be custom, can be got from a couple of people including myself (check my sig)

Gear linkage: you can use your 325i gubbins which is perfect

Radiator: when i first done my swap i was using my 325i rad and it suprisingly held out well even stuck in traffic on a blazing hot day,im now using a 535i rad from an e28 (old 5 series) you can use a non air con rad from the e34 535i.

Wiring: the loom plugs into the e30 body loom but 2 wires have to be cut and swaped over then a wire from the body loom needs to be earthed and thats it.

Exhaust: you can use your 325i system cut and sleeved into the 535i downpipes or use an exhaust from an e30 M3 (50mm pipes)

As far as i remember thats it!

thank you very much for your help! its certainly cleared my head abit with all the technical jargon ive read.

the main worry i had was gearbox and prop as like i said, this is my 1st bmw conversion and my first rwd one too!

im going to start searching for a decent donor car, soon as ive found one il be having a set of those mounts off you lee.

thanks for moving it too gareth. such a useful forum!

what is involved with the gearbox flange swap then? if i remember correctly they just have a centre bolt dont they?

cheers again, dan

dirtydog100 wrote:what is involved with the gearbox flange swap then? if i remember correctly they just have a centre bolt dont they?

cheers again, dan

Yes, its a 30mm nut then the flange slides off the gearbox, the flange must be off a 325i though as the splines on the shaft match.

thats ok ive got a 325i, one less thing to worry about then lol.
what are the gear ratios meant to be like on the 325 sport boxes? it has quite a long 1st gear it seems.

what power outputs would this conversion give? Im comparing this to the 2.8 m20 conversion and am not sure which is best.

M30 power depends on the exhaust fitted (325i or M3). my M30 has 220BHP and 238lb.ft of torque with a scorpion system. the only modifications from standard when that was measured were the exhaust, a 1mm head skim (9:0 up to 10:1 CR) and a catflap blowback plate fitted for LPG operation, which will restict the inlet.

for a bog standard M30, anywhere between 200 and 215bhp depending on the age / condition / milage of the engine you find. the torque is immense though

holy shi* i didnt realise they were that torquey! awsome!
my mind is 100% on the m30 now lol
ive got a full scorpion system and no cat either so hopefully be a fair way over 200!

you may not get peak power / torque with your existing scorpion system as the bore is smaller than the M30 would normally have, hence the larger M3 system on mine. i don;t know how much you'l lose though to be honest.

i think the standard torque is about 210 - 220 lb.ft or thereabouts. plenty

Well no need for me to input in this post, it's all been said.
Have fun though

If you have an 86 sport, why not swap it for my tech1 335 touring with the diff on it.

i like the shape of the coupe, plus id rather do the conversion to mine, its more satisfying.
ive bought ready made cars before and they become boring, half the fun is in the building it up the way you want it.

but thanks anyway.

I just want another tech 1 lol.

lol, ive wanted one for about 4 years, its taken me that long to find the perfect one too! black with black leather. ive had a couple of other e30s and an e36 but this is the best one ive owned!

i may well do a build thread if people are interested????? itl be my 1st bmw conversion but y no means my 1st ever engine swap.. vauxhall is was my forte.

Happy new year everyone.

gareth wrote:you may not get peak power / torque with your existing scorpion system as the bore is smaller than the M30 would normally have, hence the larger M3 system on mine. i don;t know how much you'l lose though to be honest.

i think the standard torque is about 210 - 220 lb.ft or thereabouts. plenty

I think i'm going to change my exhaust to 3" straight through.
Go and get a price, then put this stainless one up for sale.

dirtydog100 wrote:i may well do a build thread if people are interested?????

Build threads are always good!