M20 Engine Swap - Full Wiki Guide

[Grrrmachine]

Here you go chaps:

http://www.e30zone.net/e30zonewiki/inde ... Swap_-_M20

Short of a few photos, it's pretty much complete. This will help you through all the ins and outs of fitting the straight six motor to your E30.

Sticky?

[Jimcrack]

Can I use a saloon 325i as a donor car to put in my 318i coupe? Any differences?

[maggspower]

Can I use a saloon 325i as a donor car to put in my 318i coupe? Any differences?

Yes you can, but have a look at the picture in the wiki of the brackets on the N/S inner wing. Your 318i will not have these so they will need to be cut out and welded into the engine bay. This is somewhat dependent on pre and post facelift issues too.

Unless you are happy with cable ties.

[Grrrmachine]

No such thing as a coupe on E30s. Just a 2-door saloon, so no problems

[gooner1]

Here you go chaps:

http://www.e30zone.net/e30zonewiki/inde ... Swap_-_M20

Short of a few photos, it's pretty much complete. This will help you through all the ins and outs of fitting the straight six motor to your E30.

Sticky?

Nice work Grrr, definitely should be a sticky.

Could I also add, re suspension, that the 323i also shares the
same 51 mm struts as the Touring and Convertible.

[Grrrmachine]

Cheers gooner. Changes made

[Jimcrack]

Thanks for the help guys!

[breihill01]

Can the post and pre facelift issue be solved by fitting the water pump that is car specific?

Im considering 1989m20b25 into 1987m20b20 but dont really want to have to move the expansion tank to the other side.
Gasket numbers are the same so not sure if there is any other issues.

Guide is excellent


Lifted directly from the wiki page
Cooling
The coolant system for all M20 engines is pretty much the same, with radiators varying slightly in size but not having any real effect on the quality of the cooling. The one significant difference is the expansion tank. For engines before 1987, this was bolted to the right-hand suspension turret, just in front of the battery. For the 1987 facelift it was relocated to the LH inner wing, just behind the headlight, and the hoses re-arranged accordingly. This difference is clearly visible with the water pumps available for the engines, whose outlets change to suit the plumbing layout.

Either of these expansion tanks will need to have a bracket fitted to hold it. If you don't want to do any welding and you aren't happy drilling holes in your car to use ordinary bolts, there is a third solution; a 318iS radiator, which has an expansion tank on the side. You'll just need to get creative with your cooling hoses to make sure it's all plumbed in correctly.

Finally, your radiator is held in place on plastic mounts which clip into holes on the chassis rails. These mounts will be different to your existing radiator mounts, and need to be sourced. They are two different sizes; one short, one long. There have been reports that various radiators don't fit these mounts despite being sold as Genuine BMW radiators, so prepare to be creative with your mounting arrangement, or source another radiator.

[gromgsxr]

Yup I fitted a pre facelift engine in a facelift car used the face lift rad and hoses and bottle just bolded the facelift water pump to the early engine. While the engine is out do the sump gasket its a pita engine in car and if ya got the timing belt off to do the pump change the belt and tensioner as well

[breihill01]

was going to do water pump timing belt sump gasket and the oil seals on the crank and gearbox along with clutch and flywheel since engine is sitting on the deck.

good to know they fit that way round.
Cheers