E12 528 carb to motronic conversion

Falkenberg · Post by **Falkenberg** » Tue May 15, 2012 7:14 am

Hi,

I stumbled upon a 3.5 motronic engine from a '87 E32 ( yes, with correct engine mounts for the E12

) and I think I'l give it a try in my '76 carburetor car.
I think I can solve the electric issues. But I don't know about throttle linkage. My E12 has a linkage of rods for throttle control, the E32 had a cable. I suppose that I'll 'upgrade' the E12 to cable as well. Is there any plug and play solution for this?

Thanks for any tip/trick..

LE: Use search and you will find:
http://www.firstfives.org/bboard/viewto ... le+linkage
http://www.firstfives.org/faq/motronic_ ... ersion.htm
http://www.firstfives.org/bboard/viewtopic.php?t=1965

Anyway, I'll follow up on this thread if I encounter any surprises.

Bart.

labimmer · Post by **labimmer** » Tue May 15, 2012 11:42 am

How you are going to solve electric issue. If you solved that you should be fine with the rest. Are you swapping the radiator as well. Also if your car is from 1976 brake booster sticks out could be a problem for intake manifold

On 05/15/12, Falkenberg <bekkerbart@yahoo.co.uk> wrote:

<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">

Hi,I stumbled upon a 3.5 motronic engine from a '87 E32 ( yes, with correct engine mounts for the E12 ) and I think I'l give it a try in my '76 carburetor car.I think I can solve the electric issues. But I don't know about throttle linkage. My E12 has a linkage of rods for throttle control, the E32 had a cable. I suppose that I'll 'upgrade' the E12 to cable as well. Is there any plug and play solution for this?Thanks for any tip/trick..Bart.
1961 Simson AWO sport (Brasoveanca)1968 BMW 114 20021976 BMW E12 528 (Malèna)1987 Kawasaki GPz900r
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pappentl · Post by **pappentl** » Tue May 15, 2012 3:51 pm

There is a cable that is available for the e12 as shown on this site. I just bought one for a motronic conversion.

http://realoem.com/bmw/showparts.do?model=3771&mospid=47156&btnr=35_0072&hg=35&fg=10

...tom

From: Falkenberg <bekkerbart@yahoo.co.uk>
To: tech_forum <tech_forum@firstfives.org>
Sent: Tuesday, May 15, 2012 at 8:15 am
Subject: E12 528 carb to motronic conversion

Hi,

I stumbled upon a 3.5 motronic engine from a '87 E32 ( yes, with correct engine mounts for the E12

) and I think I'l give it a try in my '76 carburetor car.
I think I can solve the electric issues. But I don't know about throttle linkage. My E12 has a linkage of rods for throttle control, the E32 had a cable. I suppose that I'll 'upgrade' the E12 to cable as well. Is there any plug and play solution for this?

Thanks for any tip/trick..

Bart.

1961 Simson AWO sport (Brasoveanca)
1968 BMW 114 2002
1976 BMW E12 528 (MalÃ¨na)
1987 Kawasaki GPz900r

-------------------- m2f --------------------

Sent using Mail2Forum (http://www.mail2forum.com).

Read this topic online here:
http://www.firstfives.org/bboard/viewtopic.php?p=14790#14790

-------------------- m2f --------------------

Post generated using Mail2Forum (http://www.mail2forum.com)

Jeff Dennis · Post by **Jeff Dennis** » Tue May 15, 2012 9:05 pm

If you are in the US I would be interested in purchase of your intake manifold.

pappentl · Post by **pappentl** » Tue May 15, 2012 9:48 pm

who's manifold are you interested in? I have several stock e12 manifolds and FI systems.

...tom

Falkenberg · Post by **Falkenberg** » Wed May 16, 2012 2:25 am

Thanks for the replies.

I am outside the US, so, sorry. I was not going to part the old engine anyway. I see the motronic 3.5 as a temporary engine.

I should be able to sort out the electrics myself. If not, I'll have to return my electronics degree..

And I know about the manifold issue.. I just hope it will clear. If not, I'll have to think of something else. Either a different booster, or a different intake manifold.

What about heater hoses? Do I have to make something of my own, or can I use something existing?

Mike W. · Post by **Mike W.** » Thu May 17, 2012 9:42 pm

I believe the fitting is still there on the back of the head even though it isn't used. Just swap the water outlet.

Falkenberg · Post by **Falkenberg** » Fri May 18, 2012 2:08 am

On the head? That is interesting. I forgot about that one.

I will be in Denmark next week for my job, meanwhile my trusted friend who is also a mechanic will try to fit the engine in the car. If all goes well, I'll be working on electrics and cooling in 2 weeks.

Jamie · Post by **Jamie** » Wed Jul 18, 2012 10:38 pm

Jeff Dennis wrote:If you are in the US I would be interested in purchase of your intake manifold.

What are you looking for? I am in Idaho, lived in Huntsville for ten years, a while back. I have various intake parts....all off of 80-81 cars. Jamie

Jamie · Post by **Jamie** » Wed Jul 18, 2012 10:39 pm

Jeff Dennis wrote:If you are in the US I would be interested in purchase of your intake manifold.

What are you looking for? I am in Idaho, lived in Huntsville for ten years, a while back. I have various intake parts....all off of 80-81 cars. Jamie

Jeff Dennis · Post by **Jeff Dennis** » Thu Jul 19, 2012 8:34 pm

Jamie,

I would be intrested in the single carb intake manifold that came stock on european cars...got one?

Jamie · Post by **Jamie** » Thu Jul 19, 2012 10:37 pm

Jeff Dennis wrote:Jamie,

I would be intrested in the single carb intake manifold that came stock on european cars...got one?

That would be a negative...sorry about that Jeff. I think the motor I have out in the garage is a Euro motor, but, alas it is a 1980 3.3 fuel injected beast. Jamie

Falkenberg · Post by **Falkenberg** » Fri Aug 03, 2012 2:04 am

Slow progress, I hope to start the beast today or tomorrow.
Electrics are in place, for a proof-of-concept at least, but the oil light didn't turn off while cranking. Turns out that you can't use the E12 filter + support on the motronic engine, because the engine block has an extra channel in it, enabling the oil to go from engine carter to pump to filter and back to engine carter again when you use the E12 filter

You live, you learn.

Got all kinds of other small problems as well, that we've sorted out. Mainly, missing bearing on engine side for the manual gear box axle (engine was from an auto car). Wrong gear box support, apparently 5 speed have different supports, or at least some of them. No nipple on the intake for brake vacuum (apparently a 1987 E32 735i has a hydraulic brake booster!), and not even some stud on the intake where it was supposed to be. Solved it by using the vacuum connection for the carbon canister. I just hope that it will be sufficient, wouldn't like to run out of air while pumping the brakes.

Oh, I'm converting from carbs to injection. Where should I place the fuel pump? Right now I just mounted it somewhere in the engine bay, but I guess that it should be under the car somewhere?

When I have the oil pressure problem sorted, I can finally start the engine. And then I have yet to make the throttle linkage and finalize electrics.

Falkenberg · Post by **Falkenberg** » Fri Aug 10, 2012 2:10 am

So this is where we stand:

Now I have to sort the details.
The 5 speed short-ratio is a bit strange to get used to. In fact, 1st gear seems useless with this setup, I probably need a different differential.

Falkenberg · Post by **Falkenberg** » Wed Aug 22, 2012 2:21 am

Up and running now.
Still have to tinker with the acceleration, it feels a bit slow at low throttle, and I can't get to WOT yet.
Also I'm not sure it it doesn't run a bit to hot. Fan clutch is new, fan blade is from a E36. it looks larger then the old 2.8 fan, so I figure that it should do the job.

First impressions:

It doesn't really seem to matter in what gear I am running. Pulls well in any, even in city traffic (still have the 3.64 diff). The feeling is like a locomotive. The old 2.8 did not have that amount low-end torque, but possibly offered more thrill when revved.

The 5-speed dog leg is useless, also because of the 3.64 diff. I am not sure what I need 1st gear for. It also shifts less smooth than my old 4-speed. Got some play in the linkage, attributing as well. I did exchange some things there but apparently forgot something.

Brakes need to be restored with a higher priority then before.

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