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E30 M10 318i into an E21 316 Carb
Posted: Thu Aug 11, 2011 1:14 pm
by Reck
I've been banging on about it for months but my M10 is really ill now! Having to drive everywhere with the heater on full blast and losing oil and coolant as fast as I can replace it. As above really..
I know it'll need some fiddling about with the wiring loom but there are old posts on here that detail that. Are there any other considerations? What about the fuel pump? Also, can I transfer my ancillaries across (esp alternator.. I bought a brand new one not so long ago).
Thanks!
Re: E30 M10 318i into an E21 316 Carb
Posted: Fri Aug 12, 2011 11:13 am
by pilly
I've done this one before and it was surprisingly simple. You will need the e30 fuel pump as it is a much different pressure to the carb cars. Also battery to the boot will need to be done. most of your ancillaries will just swap, the alternator however does require the e30 mounting arm. Wiring is fairly simple and i think a post had all the colour convertions on it. So good luck
Re: E30 M10 318i into an E21 316 Carb
Posted: Fri Aug 12, 2011 4:11 pm
by Reck
Brilliant. Thanks for the advice.
As an aside.. Does anyone know if there is a site that lists all the M10 variants? I'd like to look for whichever version is the toughest!
Re: E30 M10 318i into an E21 316 Carb
Posted: Fri Aug 12, 2011 8:40 pm
by drjim
They're all tough!
I'm thinking about M52ing the slug so my nicely rebuilt M10 with EFI etc will be up for sale, I suspect your budget and my price will be wildly incompatible though!
Re: E30 M10 318i into an E21 316 Carb
Posted: Fri Aug 12, 2011 10:08 pm
by Blackadder
Little correction,
Battery can stay at its original place.
fuel pump was mounted in the boot.
the "black box" was mounted between dashboard and glove-box.
I've parted out a 316 with E30 1800i.
The engine will be mounted in Cerberus' car.
He can tell you more about it.
I think there's a little bit of engineering to be done about the air intake.
So the 1800i from E30 is almost "plug and play"
I think I have some pics in the archive...
Re: E30 M10 318i into an E21 316 Carb
Posted: Wed Aug 17, 2011 1:16 pm
by Reck
Thanks for the info Blackadder - re the fuel pump, is that not mounted in the tank?
Also, I've been offered a 2L M10 4 pot from a 1978 320i - didn't even know such a thing existed! Does anyone know of any potential issues if I went for this? It has been sat unused for 5 years though. Really wouldn't mind a 2L.

Re: E30 M10 318i into an E21 316 Carb
Posted: Wed Aug 17, 2011 2:40 pm
by drjim
1978 320i will have injectors in head, run on K-jet and should work fine. If it's not a runner you are taking a chance - it may have rust in the bores if not been oiled from time to time, likewise bottom end could be knackered. You are getting into need to rebuild territory. The engine in the slug was a 2L from an 02 originally which looked nice and had been looked after, bottom end turned out to be fine but the head gasket went as soon as it got running, and the head apparently had a crack in it as well. When it came apart for that I ended up doing new pistons etc and spending lots of cash.
My advice - having been through all this myself - is to get another known running 1.8 engine, ideally the e30 318i one, stick it in and use the car. It'll do 30mph on side roads and 70mph on the motorway, the way roads/traffic/police/cameras are now, any more is tricky. Unless of course you want to start doing track days etc in which case rather than rebuild an M10 you can just buy mine!
Re: E30 M10 318i into an E21 316 Carb
Posted: Wed Aug 17, 2011 3:06 pm
by Reck
Scrap that then. Ta for the info.
I got in touch with Neil and he said the only M10 he has is a 1.6 from a 1502. I'm stuggling to get hold of the guy Jason knew with the £50 M10, Fritz want £250+VAT - I suppose my last hope is Rav! I'm starting to wonder if it's not going to be easier to sort mine out. This is the list of symptoms;
- Overheating (suspect head gasket as exhaust gases pressurising coolant system causing airlocks and leakage from rad cap)
- Drinking oil (unsure whether related to above - consumption dramatically increased in recent weeks - don't think it's burning it though as I haven't noticed any blue smoke, only an occasional puff of white smoke under heavy acceleration)
- Water jackets rusty in engine?! (Have flushed several times with diff products and it always turns brown a day later)
The head gasket is straightforward but if I do it on a weekend I've got no way of getting it skimmed if warped (could even be cracked for all I know). The oil drinking and rusty passages I've no idea on..
Re: E30 M10 318i into an E21 316 Carb
Posted: Wed Aug 17, 2011 10:43 pm
by mr edd
a early (1977-1979) m10 2 ltr injection engine has injectors in the manifold not in the head ..the cam would only be suitable for a points dizzy and coil as a points dizzy spins the opposite way to electronic dizzys and the inlet/exhaust ports are larger on the 2ltr head (the same size as a e30 m10 318i) than on a 316 e21....the 1.6 1502 engine would be the easyest to fit if you could sort out useing a points dizzy as the ports on the head are the same size as on a 316e21 head ...the engine currently in my car is a 1.6 316 1979 engine (points dizzy)with a modded engine bay loom to suit the dizzy and 316 carb and manifold also from a later x plate car that would have had a electronic dizzy originally..p.s a 1502 engine and a early e21 316 engine are same thing ..edd
Re: E30 M10 318i into an E21 316 Carb
Posted: Wed Aug 17, 2011 11:00 pm
by mr edd
also if you put a early engine in a later e21 you will need the engine mount for the exhaust side as the holes on the block are different place and your mount would not fit ...
Re: E30 M10 318i into an E21 316 Carb
Posted: Wed Aug 17, 2011 11:07 pm
by drjim
I had that with the slug, brand new mount was about 15 quid from BMW.
Fixing the head gasket may fix the problems you are having, but can't be certain. If the oil is vanishing but not obviously burning off, is it going in the water - do you have mayo under the filler cap??
Re: E30 M10 318i into an E21 316 Carb
Posted: Wed Aug 17, 2011 11:09 pm
by drjim
Re: E30 M10 318i into an E21 316 Carb
Posted: Thu Aug 18, 2011 10:36 pm
by Reck
No mayo under the cap.. There's traces of oil on top of the air filter housing though?! The water has never seemed oily but it does go dirty brown extremely quickly after flushing. Might dump a bottle of engine stop leak in - can't hurt I suppose!
Been offered a running direct replacement from an E21 316 on E30Zone funnily enough. £150 with 80k on it and dealer stamps up to 70k. Guys gonna send me a video of it running and if I'm happy with that I think I'll go for it..
Re: E30 M10 318i into an E21 316 Carb
Posted: Thu Aug 18, 2011 10:44 pm
by drjim
Sounds like a plan. How soon do you want to get it fitted?
Re: E30 M10 318i into an E21 316 Carb
Posted: Thu Aug 18, 2011 11:08 pm
by Reck
It's still in the car so I'm guestimating the weekend of 3rd Sept but I'm more than willing to slot around whenever is best for you and Murran!