Help! with E30 316i M50 swap

Post Sat Oct 17, 2009 10:13 am

Hi all, i've been thinking for ages about doing an E30 M50 but havent got much of a budget. Finally a couple of months ago i bit the bullet so to speak and found a bargain of an e30 316i (£230 2 door manual in really good condition)and shortly after i got another bargain of an e34 525i sport (£450 1991 pre vanos manual) donor. The E30 is stripped and im in the process of stripping everything out of the e34. I dont suppose there is anyone local to me (South Herefordshire) that has some experience of doing a swap like this? I'm just a bit concerned Re. steering column/exhaust manifold modification, wiring loom modification etc.

Any help would be much appreciated

Post Sat Oct 17, 2009 10:19 am

what part of herefordshire?

Post Sat Oct 17, 2009 8:23 pm

There's a group buy going on for steering linkages in the group buy area at the moment that might make the exhaust side of things a bit easier.

The electrics aren't *that* bad, you just have to take your time. I cut the end of the e30 engine loom and soldered it onto the m50 engine loom, used a combination of various other peoples diagrams to figure out what was what. I think theres someone that sells pre-made adaptors though. I'll post what I ended up with for a non-nanos into a 1990 320i if you want?

Post Sat Oct 17, 2009 8:28 pm

If you want to buy a plug n play loom then PM a member called DanThe

He is also doing the steering linkages so you don't need to cut the rear branch of a M52 manifold at the flange where it bolts to the head, you still need to cut off the flanges where the downpipes connect and weld pipes to them

Post Sun Oct 18, 2009 12:10 am

Thanks for your replys ive just spent the day stripping more off the e34 but just read in a couple of places that an e34 LSD wont fit an E30!?!? can anyone shed any light on that?

Post Sun Oct 18, 2009 12:15 am

I'm in Ross-on-Wye by the way

Post Sun Oct 18, 2009 12:25 am

I'm not 100% but i believe the E34 diff will be the large case variety whereas the E30 ones in the 6 pot cars are the medium case. The large case stuff won't fit the E30.

If you're starting with a 316i then you'll need a 325 prop and a diff from a 325, either a 3.91, 3.73 or 3.64.

I have a 3.91 in my touring with M52 engine. 70mph is at 3k revs, it can be a bit buzzy on a motorway journey if you are sitting at 80 for example

Post Sun Oct 18, 2009 12:39 am

pm sent as am after some e34 goodies!

Post Tue Oct 20, 2009 8:19 am

blue30 wrote:There's a group buy going on for steering linkages in the group buy area at the moment that might make the exhaust side of things a bit easier.

The electrics aren't *that* bad, you just have to take your time. I cut the end of the e30 engine loom and soldered it onto the m50 engine loom, used a combination of various other peoples diagrams to figure out what was what. I think theres someone that sells pre-made adaptors though. I'll post what I ended up with for a non-nanos into a 1990 320i if you want?

If you could, that would be great

Post Tue Oct 20, 2009 9:45 am

guts of the e34 diff will go into an e30 casing.. It'll cost to get it swapped, but less than buying another diff..

Post Thu Oct 22, 2009 4:05 pm

booomer wrote:
blue30 wrote:There's a group buy going on for steering linkages in the group buy area at the moment that might make the exhaust side of things a bit easier.

The electrics aren't *that* bad, you just have to take your time. I cut the end of the e30 engine loom and soldered it onto the m50 engine loom, used a combination of various other peoples diagrams to figure out what was what. I think theres someone that sells pre-made adaptors though. I'll post what I ended up with for a non-nanos into a 1990 320i if you want?
If you could, that would be great

OK hope this makes sense -

On the e30 side we've got:

1 Blue Alt chg+
2/3 not used
4 brown/purple coolant temp to dash (put e30 brown sensor on m50 engine)
5 brown/green - oil pressure switch to dash
6 green/white run/start live (o2 heater feed??)
7 green start
8 white/black econo-meter signal
9 black tacho signal
10 blue oil level warning for check pannel
11 white/green - dash service light reset
12 green engine fault / check engine warning
13 purple/green fuel pump relay
14 black/white road speed sig to ecu
15 black/green unloader relays
16,17 not used
18 black/yellow go baby go (starter solenoid)

On the M50 side (non-vanos) I had:

1,2,3,4,5,6,7 - not connected/needed (2 might be oil level if the donor had one)
8 grey engine fault/cel
11 brown/yellow water temp (redundant on e30)
12 brown/purple water temp (for dash)
13 green/purple fuel pump
14 black/white road speed sig
15 black/green unloader relay
16,17 - diag connector, redundant on e30
18 black/yellow go baby go (starter)
19 white/green service light reset
20 black tacho sig
21 green ignition on (had 2 wires on 1 pin)
22 green/white ign +12v (o2 sensor heater??)
23 brown/grey (oil pressure switch)
24 white/black econo-meter signal
25 blue alt charge warning+

So just match up the functions there, I chopped the plug off the e30 engine loom and connected that to the m50 engine loom. Soldered with heatshrink and masses of black tape over the top.

re. the colours, e.g. white/black is white with a black stripe, black/white is black with a white stripe... confuse-o-rama.

There are some really useful diagrams of the cooling system on the realoem site, if you look up the e36 cooling system on there. It helped me to figure out where everything went cause I never saw my m50 in its donor.. My donor had the header built into the rad by my 320i had a separate header - connecting the smaller long pipe from under the inlet manifold to the bottom of the 320i header tank and keeping the 320i rad works fine.

I had to reverse the heater connections from the way that the realoem diagram shows though as I had no heat until I did that. The top e30 heater stub had to be turned upside down, otherwise it hits the m50 manifold. you'll see what I mean when its in front of you!

I'd read a couple of people say they couldn't understand what the servo biz was about cause they had no problem using the e30 servo, but I tried and there was no way whatsoever, it was pressing hard on it. I tried putting a few washers on the engine mount on that side but it would have needed a crazy amount of them to sort it properly and its just taking space away from the exhaust manifold as you rock the engine over. Also you'll have to pad the gearbox mounts too. Basicly just get an 2000 ish clio servo.

HTH!

Post Fri Oct 23, 2009 6:39 pm

thatnk for that, very useful info on the wiring side of things (thats the scaryest part) is the clio servo an exact replacement of the bmw one or are spacers/modifications required?

cheers

Post Fri Oct 23, 2009 7:42 pm

booomer wrote:thatnk for that, very useful info on the wiring side of things (thats the scaryest part) is the clio servo an exact replacement of the bmw one or are spacers/modifications required?

cheers

You will need a bit of 10mm bar to slide down the operating hole of the master to ,in effect,lengthen the servo's push rod.
I found that 5mm was about right,but needed to experiment.Be wary of too long a spacer,it makes the rear brakes run hot...

Post Sat Oct 24, 2009 11:30 am

Mine needed about 20 something mm, but you'll see when you've got them both in front of you - the push rod in the e30 servo comes out just past flush with the front of it but the clio one sits well back inside.

I have a vague memory of having to drill out the holes where the pin goes through the e30 lever arm too... oh and you'll need to adjust the e30 braking bar thingy so that it doesn't keep your brakes on all the time!