E30 Zone

Yo dudes - looking for torque and better mpg, am planning to transplant a 5 series eta engine and auto gearbox from an 1986 car into my nice but sluggish 1990 320i auto. Am I mad? And if I'm not, and with apologies if this has been covered before, (although my search couldn't find it), can I simply slot the engine/gearbox in and hook things up to the existing prop, or is life more complicated? Would I use the eta engine loom or can I adapt the one already in the 320i auto? All advice gratefully received. Spiderdog

Build a 2.7:

How to build a 2.7 'clicky'

Cheers, mate. Sorry, I can see the wiki tells me all I need on the electrical and engine development side. But I'm less clear about the installation side of things. Is it really a case - if I'm keeping the auto box - of just bolting the engine and transmission to the existing mounts and auto prop? That seems a bit too easy. Spiderdog

Get in touch with daimlerman mate. He has a 2.7 and will tell you all you need to know

Will do. Thanks for the advice. Cheers, Spiderdog

No problem mate, good luck and keep us updated

drop the 2.0 head on the 525e engine and you have an instant 2.7 with plenty of torque

The basics of a 2.7 build involve putting a 320i or 325i head onto a 525e block. Then you get the long stroke torque of the 'e' and the higher revs/power of the 'i'.

However if you want to just put the 525e engine into your 320i it should just be a case of changing the sump & oil pickup/pump?? and swapping the whole engine and gearbox assembly into your car.

Dont just take my word though cause there are probably some other bits and bobs to sort out.

Cheers
Chris

Exchanged PM's with the OP today,I think this is a brilliant idea that will work well,for others interested the 'eta' M20 will need the E30 specific items installing,these include the sump as already mentioned,and the waterpump/cooling system.Engine management will need looking at,the original 320 will be the simplest to use,a suitable chip for the ECU from Ant will be needed.
Cylinder head from the 320(731 casting)with a 325 cam will be fine.
Fueling will also need work,simple way is a 325 inlet with all it's fittings.

The way I read the post he wanted to create a 325e not a 327i so in this case fitting the E28 engine as it comes with a swap on sumps should be all that is needed. The 320i if its post 1988 won't be L-jet so the the engine managment will suffice with a chip. If its pre 1988 then convert it run on motronic 1.3 and A-tech should be able to create a chip for an eta M20. If you keep the eta cylinder head I see no reason why a change of water pump will be needed. The 320i exhaust manifold should match the exhaust ports of the eta head if manifold is the same as the 520i item so the 320i exhaust system might not need altering.

However ditch the auto and convert to a manual it is much smoother and quciker! Also fit a 3.46:1 diff or lower. If you keep the 3.91:1 diff a 320i has with an auto car you would top out at 110mph and with a manual you would reach 105 mph. This is due to the 4750 rpm limit but peak power for a stock eta comes in at 4000 rpm and torque and power fall rapidly away as you approach the red line. A 3.07:1 ratio from a eta would work fine but I found in my 525e that a 3.46:1 shaved 2 seconds of the 0-60 time and was no more fuel inefficent and top speed rose to 120 mph from 110 mph! So why did BMW fit the 3.07:1 in the first place.

A manual 325e is not slow even with a tall diff (they were sold in north america and europe) with a suitable diff it will be alot quicker. Infact it is project I have in mind. Given the weight of E30 you should reularly see 35 mpg average which is what I used to get out of my 525e with very careful driving before it got worked over. With the e to i conversion I just get 31 mpg average. I can live with that though.

Good luck.

eta wrote:A manual 325e is not slow even with a tall diff (they were sold in north america and europe)

Your right, but the 325e had an 885 cylinder head, not the 200 head the 525e came with so is a completely different engine....

The early 325e had a 200 head but from March 1987 or so they gained the 885 head as did the 528e.

eta wrote:..... If you keep the eta cylinder head I see no reason why a change of water pump will be needed....

Waterpump has nothing to do with the cylinder head,the E28 waterpump is too long to clear the radiator and other pipework when fitted into an E30,an 'eta' engine is just a long stroke M20, so instalation into E30 requires the E30 'dressing'.