745i turbo motor transplant to 3.0cs

7173bmw

7173bmw

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Hello everyone!

New to the board and looking for some insight!

I have an '84 745i turbo that I would like to pull the motor out of and install in a '73 3.0cs that I will be picking up next week after Christmas. While the 745i is in pretty good shape(needs paint, seats need to be dyed, and engine harness reinstalled), the idea of putting that motor in a 3.0 after tear down, sandblasting, fresh paint, etc....just keeps me reeling!

Outside of the motor, exhaust, wire harness(I may go mega squirt and make my own harness), what else do I need from the sedan before I part out or sell whole?

Can I use the differential since it has a LSD?

Thanks for your help!
ND
 
the ear axle is the same as in e24, right?
somebody told me the e24 rear axle would fit in a e9...
but if that is true, then i'd replace the entire rear axle
 
The 745 engine compartment is much larger than the E9 and squeezing everything in will be a challenge. Save all the mounting brackets, etc. for the turbo and injection system to use as patterns in the conversion.

The 745 diff will not work in the E9 without major fabrication.

E24s up to 1981 (and maybe 1982) used the same sideloader diff as E9s. After that they used the same diff as E28s, which don't fit E9s.

What transmission are you going to use?
 
I seem to recall that the stock 745i ducting from (to?) the turbo will want to occupy the same space as a frame rail in the E9. It's not a fatal issue, but one that would be nice to know about beforehand so you can make alternate plans for routing exhaust plumbing.
 
Thanks guys!

Bill: I'm going to look for a 5 speed to bolt up. I have a 4 speed but don't believe it will do the job.

Any suggestions?

ND
 
Michael,

Thanks so much! Awesome thread!

What are your thoughts: mega squirt or no m/s?
Thanks,

ND
 
I'm driving a1987 545i this week that I installed for a friend last year -hauls ass!
I went for a water to air intercooler at first and right I am running with no intercooler.
You will need to make a custom pipe from the turbo to the throttle body. -[ think in terms of the tubing only up the pass. side of the engine]
Or you can buy it from David at ecartoyz.
Let me know if you want pics.
Car is currently running stock 745i turbo wiring but was brought in the Mega squirt install
FYI- I fit the m106 turbo engine in a coupe 2 years ago- it helps to notch the top flange of the right frame rail.
 
Thanks SFDon!

Any pics you can send my way would be appreciated! Any pics of the frame work you did?

Thanks,

Nick
 
sfdon said:
I'm driving a1987 545i this week that I installed for a friend last year -hauls ass!
I went for a water to air intercooler at first and right I am running with no intercooler.
You will need to make a custom pipe from the turbo to the throttle body. -[ think in terms of the tubing only up the pass. side of the engine]
Or you can buy it from David at ecartoyz.
Let me know if you want pics.
Car is currently running stock 745i turbo wiring but was brought in the Mega squirt install
FYI- I fit the m106 turbo engine in a coupe 2 years ago- it helps to notch the top flange of the right frame rail.
Click to expand...

Anything that you can share in the way of fitment, photos, routing, how many beers it took, would be very interesting. I had an '84 745i donor car that I was planning on putting the engine from into a coupe several years ago. I never made the time and ended up selling the 745i. I had both cars side by side and did a lot of measuring, and from what I remember the engine compartment/frame rails in an '87 5-series was basically the same as a coupe. The rails are at least an inch narrower than the 745i, which doesn't sound like much but it is.

A manual transmission will also require a blow-off value setup.

Dan
 
this pic shows the m106 I installed in a 86 or so e28 that I did last year-
Biggest problem was the passenger side engine mount, I went with the 533i mount and a stack of washers... a little dremel work made it possible. Clocking the intake side of the turbo and using a ecartoyz intake with attached blowoff leaves only the brake lines to be bent out of the way of the wastegate and exhaust manifold. Not that tough of job really. Terry C has the coupe that we altered the pass. side frame rail- lets see if he can post a pic of that. The key thing here is there is a way around the m102 and m106 tubing to the front of the car and the intercooler way up there. Also- the oil pan from the m106 gets replaced for the coupe pan.This car was set up for water to air intercooling with a heat exchanger and a water pump.
There is a write up on the m106 install somewhere- possibly first fives?

Last thought here- after building a lot of 250 to 350+ hp engines for coupes and e28, e32, e23, Bavs etc.- lots of hp does not always make a car that great. The e9 with 300 hp is a lot to handle......
 

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sfdon said:
Last thought here- after building a lot of 250 to 350+ hp engines for coupes and e28, e32, e23, Bavs etc.- lots of hp does not always make a car that great. The e9 with 300 hp is a lot to handle......
Click to expand...


Don knows! (listen to him dreamers!)
 
Don knows! (listen to him dreamers!)

Originally Posted by sfdon
Last thought here- after building a lot of 250 to 350+ hp engines for coupes and e28, e32, e23, Bavs etc.- lots of hp does not always make a car that great. The e9 with 300 hp is a lot to handle......


I'm old enough to heed the advice of experience! Is there a book someone can suggest for motor mods for this engine? Maybe a hot cam upgrade, carb swap, t-bitz set up, etc...?

Does anyone know where I can get engine specs? Compare motors, see where I have the most potential. Maybe take the motor from the 745i, pull the injection and turbo off, do some mild mods and throw 3 sets of side draft weber carbs. What do you guys think?

Anyone know someone who wants/needs an '84 745i turbo Euro for parts? I'm going to start parting out, sell it whole or send it......

TIA!

Nick
 
Last edited:
Motronic 745i m106 is a 8:1 compression engine- only good for a turbo..

In all fairness, Carl Nelson has the best answer for price and performance- m30 b35 engine.

There are a few good engines out there- M90, 3.5 euro dirty and the m30 b35.
After that it gets down to port/polish, chips, cams, MAF over MAP.

The M90 engine is a problem because of the rings and the head gasket.
The Euro dirty is a problem because of compression and CA octane.
The M30 b35 is infesting the boneyards - lots in every yard and cheap. Already comes with a euro cam, big valves, big exhaust. Hook up a megasquirt, a MAP or MAF, port and polish, a good exhaust and you have a lot to handle.

Peter and Erik at CoupeKing has an awesome ceramic coated exhaust......
 
Boost

Try some research on the Mye28.com site. They have a dedicated section for forced induction; from mild ( 250hp) to wild ( 600hp). But as with everything, you pay to play; one way or another.

Best of luck...
 
Thanks for all the great advice guys!

Looks like the only things I'll be taking off the 745i are the BBS RS wheels. The 2800 and the 3.0cs will be rebuilt/restored with their original motors. Maybe a blackout package on the chrome and grill for the 3.0cs and some 16" minilights(anthircite with polished lips)Gonna take it slow on the projects. Slow and steady wins the race!

Nick
 
Thoughts on hot-rodding a Coupe

An Architect acquaintance blacked out the all chrome on his favorite Coupe nearly 30 years ago--and quite frankly--the result was simply not in keeping with the character of these cars--and with the passage of time the blacked out chrome treatment did not wear well with the owner either.

As an owner now nearing 40 years of ownership and stewardship of Coupes and now over a half million seat miles in stock, enhanced and high performance examples--FWIW--my vote for these cars is to put them in fine original external appearance and to then tastefully enhance their mechanicals for excellent drivability--then you have a win-win Coupe.
 
Last edited:
blumax said:
...the result was simply not in keeping with the character of these cars...
Click to expand...

I agree completely.

...lots of hp does not always make a car that great..
Click to expand...

I also agreed with this, although I would have to say that most cars with lots of horse power are a handful. If you build the car as a whole... power, handling, braking, etc... they can be a LOT of fun, but just adding power usually causes more problems than good.
 
Thanks guys for all the input!

I'm picking up several cars and will be keeping all original! The more I read here and look up info, I'm really looking forward to brining them back. I was supposed to pick up this morning but with all this snow, trailers are snowed in and roads aren't optimal.

As soon as I pick them up, I will be posting them on the registry.

If anyone is interested in my 1984 745i turbo(cheap!)...shoot me a PM. I'll be posting the car for sale later this week.
Thanks!

Nick
 
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