jasper's m10 to m42 swap

[jwetering]

Hello all.

I'm Jasper - I'm from North Vancouver up in Western Canada. I am about to swap an M42 into a 1985 318i.

I bought the e30 about two years ago as a project to tinker with. The car was run hard without coolant by the young woman that owned it and we figure it has a cracked head. Ran rough as hell but I drove it home. A house reno got in the way (g*dammit) and now here I am.

The plan was to build the m10 with carbs, pistons and a cam and I actually collected quite a few of those parts already, but the more I thought about it, the more I realized an M42 would allow me to daily drive this thing without smelling like fuel all the time. My wife might even tolerate it...

So - just this week I bought an m42 engine, gearbox, wiring loom, and ecu. 200,000 km showing on the donor car odo. I pick it up tomorrow.

I've read as much as I can on similar swaps, in particular I have read and re-read the relevant pages from the Irish44j rally-cross build thread. Lot's of good stuff there - but lots isn't there either. Not complaining - guys like him deserve hella praise for documenting their work.

The little things are keeping me awake at the moment. - like how to mount the coil packs (thinking of going COP just to avoid this) and how to mount the wiring loom on the firewall. I am also wondering how to make the old gauges and fusebox work with the new wiring loom - but I'm probably more freaked out by the unknown than I am about the job itself.

I hope to keep everyone posted here on my progress and any new things I learn along the way but at this point I am looking for a hands up from anyone who has done this swap and would be willing/able to answer specific question I come up with.

So - just introducing myself for now. I will try to get some photos up soon since I know people like that. I know I do.

PS -

Car is metallic brown with brown/beige interior. Some of you may not like brown, but it's actually one of the things that sold me on the car.

I have installed Vogtland springs with KYB gas shocks (rears anyway - fronts will be done soon). I'm looking for a firm but compliant ride, not too low. I don't need this to be a boy racer. I'm 53 years old and have a Porsche 996 for going as fast as I want already. Would like to be able to use this ar for occasional business work.

Euro bumpers -got 'em - rear is installed and the front is going on this week.

Rear decklid iS lip - black plastidipped and installed.

Rear subframe sandblasted and painted. Ireland engineering subframe and trailing arm bushings installed.

4.10 LSD installed.

I installed a really nice set of black leather sport seats - they look ok with the interior.

I bought an e46 ZHP steering rack. The stock rack was leaking really badly. The man I bought it from said it was plug and play......geez I hope he is right.

OK guys - stay tuned.

jasper

[Danny]

Check this thread: https://www.r3vlimited.com/board/sho...d.php?t=224191

[jwetering]

Check this thread: https://www.r3vlimited.com/board/sho...d.php?t=224191

Yessir - I've been up and down that thread a few times. So far it's all I have to go by and while it's good.....I was hoping for more. We shall see what pops up once I get going.

So - here's a few teaser pics:

First up the subject car. Pardon the sawdust - as I said earlier I was balls deep in a reno for that last year and that included insulating and paneling my workshop.




Second up the M42 as received on the pallet.




Third up a shot of the interior showing off my lovely sport seats.



Fourth up a shot of the m42 hoisted and partly stripped. After that I lowered it onto a moving dolly I bought on sale for $18 at Princess auto - which is just like your Harbour Freight stores.




More tomorrow - Can anyone tell me if my m10 speedometer will work with the M42 Getrag 240 ? Is the M10 Getrag 240 speedometer drive mechanical or electric ?

Thanks in advance.

And Danny - is there a way to get the photos to show up in the thread directly without using a hosting site ?


All I see is hot links. Thx

[mjweimer]

More tomorrow - Can anyone tell me if my m10 speedometer will work with the M42 Getrag 240 ? Is the M10 Getrag 240 speedometer drive mechanical or electric ?

The speedo signal should be picked up in the differential just like any other E30 - so you should be fine there.


Here is a useful link that may help with the mechanical aspect of your work:

https://www.bmwtechinfo.com/repair/main/Index_cd3.htm

Another good link to have for the electrical:

http://shark.armchair.mb.ca/~dave/BMW/e30/

Looks like you have a really nice car for the project.




MJ

[jwetering]

The speedo signal should be picked up in the differential just like any other E30 - so you should be fine there.

Here is a useful link that may help with the mechanical aspect of your work:

https://www.bmwtechinfo.com/repair/main/Index_cd3.htm

Another good link to have for the electrical:

http://shark.armchair.mb.ca/~dave/BMW/e30/

Looks like you have a really nice car for the project.

MJ

Much obliged for the links and clarity. I promise better pictures - just trying to figure out how to get them to show up in the thread without going to a file hosting site.

[ahrensNW]

You can't, really. Just use flickr. It will be so much easier in the long run.

[jwetering]

OK - activity:

I took the car outside yesterday and washed it. It's actually the first time that I've ever seen the car outside in daylight. I brought it home in October 2016 in the dark, and immediately parked it in my garage. I did a few things....and then the reno hit.

Here it is washed up. Rear suspension and subframe is done - front is not yet - hence the goofy stance. Note I got the front euro bumper mounted - that was a job as well. It was bent straight by quite a bit. I had to "english" it into a curve to match the car. Worked out well in the end.

[jwetering]

Cleaned up my shop a bit while the car was out as well.

Lined up the m42 on the cart I built. It's going to be great.......one day.





I made a list of things to do to the m42. A few things - but nothing too exotic.


re and re upper intake
re and re throttle body
re and re lower intake
re and re valve cover
re and re alternator
re and re power steering pump
re and re clutch
re and re motor mounts and arms
re and re lower sump
re and re upper sump
re and re profile gasket
re and re head gasket
re and re timing gear
re and re injectors and fuel rail
build and install COP system
clean up MUTI

The trickiest I think is to pull the head and replace the profile gasket. Not that it will be that hard - but I think it may be hard to do it in such a way that it won't leak again.

The hardest thing will probably be to clean it all up so it looks good. For whatever reason - all of the aluminum parts have a really thick layer of oxidation. That all has to be wire brushed clean.

The shop I bought it from did a compression test and they measured 225,225,250,245. The Mess Under The Intake hoses were cracked everywhere. I'm surprised this thing ran but they tell me they drove it into their shop. The odo showed 200,000 km - that's only 120,000 miles. Hopefully the odo hadn't stopped working 100,000 miles ago.

[e30sh]

Hello all.

The little things are keeping me awake at the moment. - like how to mount the coil packs (thinking of going COP just to avoid this) and how to mount the wiring loom on the firewall. I am also wondering how to make the old gauges and fusebox work with the new wiring loom - but I'm probably more freaked out by the unknown than I am about the job itself.


jasper

If you want to go factory coils, you can tack weld / bolt the M42 coil mounts to your inner fender. You also need the airbox mount. It's unique to the M42 if you want to run the factory airbox vs. cone.

Blower motor cover / harness mount will transfer over to you car.

I would fab a rectangular to round C101 harness adapter. Get all you pins right and you can just plug in the M42 harness. Tach and fuel economy wiring can be run under the dash vs. going out to C101 and back in like late models did it.

Good luck.

[jwetering]

If you want to go factory coils, you can tack weld / bolt the M42 coil mounts to your inner fender. You also need the airbox mount. It's unique to the M42 if you want to run the factory airbox vs. cone.

Blower motor cover / harness mount will transfer over to you car.

I would fab a rectangular to round C101 harness adapter. Get all you pins right and you can just plug in the M42 harness. Tach and fuel economy wiring can be run under the dash vs. going out to C101 and back in like late models did it.

Good luck.

Thanks for that - lining up well with what I was thinking.

Just to clarify - the C101 to rectangular connector is the only interface I have to worry about - and it connects the m42 harness to the fusebox ...do I have that right ?

Also - can you enlighten me about the fuel pump situation ? My understanding is that the m42 ran dual pumps - one in the tank and one at the tank outlet. I also understand that the m10 only has one pump at the tank outlet. The famous Irish rallycross thread says that he used the stock m10 fuel pump setup....do I not need an in-tank pump and if not then why did BMW install one ?

Thanks for the insight.

[jwetering]

Got some stripping and cleaning done last night by the way - looking better and giving me some comfort that this will look fine when it's done.



Some wicked aluminum oxidation though.

The pipes from the header which feed the cabin heater and the throttle body preheater have actual holes rotted through. I plan to build these up with JB weld and then file/sand them down round.

[e30sh]

Just to clarify - the C101 to rectangular connector is the only interface I have to worry about - and it connects the m42 harness to the fusebox ...do I have that right ?

Also - can you enlighten me about the fuel pump situation ? My understanding is that the m42 ran dual pumps - one in the tank and one at the tank outlet. I also understand that the m10 only has one pump at the tank outlet. The famous Irish rallycross thread says that he used the stock m10 fuel pump setup....do I not need an in-tank pump and if not then why did BMW install one ?

Thanks for the insight.

The 91 M42 used 1 in tank pump with the early style gas tank. Not sure what the M10 used. If it used a pusher pump and a main pump like the early 6 cylinder cars, the wire gauge to the intake pump is a little small. You can run a larger wire staring at the factory splice under the back seat and add the M42 style fuel pump plug.

C101 is engine harness to fuse box plug. 84-85 cars had the rectangular style on the side of the fuse box. 86 up used the round style mounted to the firewall. You just need to make an adapter so you can run the M42 harness unaltered. There are wiring aids out there from people who put i engines in early cars. Should be basically the same. WATCH pin 20...that's the fire starter pin. lol

C104 is the above the glovebox plug. The tach / ecomomy gauge go through there.

You will also need to add a lead from C101 to the check engine light if you want that feature.

[jwetering]

The 91 M42 used 1 in tank pump with the early style gas tank. Not sure what the M10 used. If it used a pusher pump and a main pump like the early 6 cylinder cars, the wire gauge to the intake pump is a little small. You can run a larger wire staring at the factory splice under the back seat and add the M42 style fuel pump plug.

C101 is engine harness to fuse box plug. 84-85 cars had the rectangular style on the side of the fuse box. 86 up used the round style mounted to the firewall. You just need to make an adapter so you can run the M42 harness unaltered. There are wiring aids out there from people who put i engines in early cars. Should be basically the same. WATCH pin 20...that's the fire starter pin. lol

C104 is the above the glovebox plug. The tach / ecomomy gauge go through there.

You will also need to add a lead from C101 to the check engine light if you want that feature.

That's good stuff right there.

There is a fuel pump located in front of my driver side rear wheel and I am pretty sure that's the only one. Standard k-jet set up I think. Irish44 said that he used his stock setup and I will too probably - unless the pump is toast in which case I may switch to an in-tank pump given what you say about it being the same tank and all.

Glad to hear the electrical won't be a bitch.

Thanks man.

[jwetering]

I blew apart the upper and lower intake manifolds as well as the throttle body. Trying to figure out what the easiest way is to get this stuff all clean and buffed. Tried closing my eyes and wishing it clean but no dice.





I plan to delete the heater element that is attached to the throttle body throat entirely (the square u-shaped piece and horseshoe shaped bracket) but I may re-install the throttle body heater itself to act as a spacer. Word is that the t-body boot doesn't line up well with the airbox otherwise.

That all said - I will have to fab and install a new airbox bracket anyway so I have flexibility as to where I mount it.

[jwetering]

Check out the gunge built up inside the intake and on my injector tips.

I plan to compare the cost of buying a set of Ford injectors against having these cleaned. The car had only 190,000 kilometres on it so the injectors themselves should still be good.