The b35 Saga Begins

HB Chris

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I am embarking on the M30b35 upgrade to the coupe. I have the motor and will hone cylinders and replace rings, bores are good, will also check bearings. It's from a 92 735i. Will send head out shortly to check and replace valve guides and seals. Using e21 runners which are longer and breath better supposedly. My son ground off the bosses and stud on each one, they now look correct. Have stub manifolds that have been welded and enlarged courtesy of Paul Cain and will keep it Motronic 1.3 with a chip which should get me close to 240HP but it's torque I want. Just good, clean useable torque. All Alu parts will be tumbled and clear ceramic coated for an OEM look and feel.

Still can't quite believe I am doing this as I have strived for originality but I am looking forward to the improved response and power. And it isn't going anywhere, I will keep it forever. I will update this post as I move forward.
 

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decoupe

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I can't remember if the D Jet manifold will match up to the b35 intake ports on the head. I know the b35manifold and b34 head are not a good match - something I'm addressing this winter. If you use the e32 intake manifold that came with the engine you get an additional increase in both torque and rwhp. Of course then you really will have said good bye to "original".

I removed everything D/L Jet and installed the b35intake, throttle body and fuel rail from a 1989 735i. The dyno showed a slight increase ( 2-3 %) in both torque and rwhp up to approximately 4000 rpm for the B35 intake and then a steady increase in both for the b35 of about 7% before redline.

Planning anything with a cam change?
 
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HB Chris

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Yes, ported b35 manifolds, longer C runners, e32 fuel rail, new harness for the ECU. I am really considering the cam as well, as Don is pushing me that direction. A friend is going to use the M30 front cover and not the Motronic Dizzy and use a staked/stripped distributor, now that will look more original.

Chris
 

Nicad

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Are you keeping the original motor? I would think yes. I wouldn't fret over originality in every department. I don't see any downside to what you are planning.
 

HB Chris

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Don't have original motor. Like most M30s from 70s they overheated, I have a 530 replacement block and 85 head which was the solution back then. I will sell rebuilt head, zeniths and such when I get that far.
 

afeustel

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You GO Chris!

As the various members of the board work through these conversions everybody learns.

Drew
 

rsporsche

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Chris,

we expect a deQ like pictorial - with all that you do and figure out. nothing less could be expected from you. seriously, it will be great to see what you do and how you do it. want to buy a header?
 

sfdon

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I would suggest an assortment of earthy chards and subtle pinots ready for my trip south along with Stan the Man for the transplant.
I get the downstairs bedroom- Dibs!
 

Sven

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Chris,

A couple of intake questions: On the longer 'c' runners, after you ground off the bosses on the side, how did you match the texture of the ground area with the surround dimpled aluminum? Also, some of them have studs threaded al the way into the inside of the tube. What exactly is welded onto the stub manifolds? Are you just filling the void by the upper bolt hole? or adding material to the sides as well?

Picture attached showing b35 port gasket. On my engine rebuild the machine shop epoxied in the void and ground a flare into the sides to best match the b35 port. A little extra thickness on the sides would be nice.

Thanks,
 

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m5bb

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Hey that's great Chris I am doing the same thing this winter.
Already have a 3.5 in the car and I'm going to go NA with side draft Webers, cam, pistons and headers. Rounding up parts.
Got a B35 head I am taking to have pressure tested today.
It will look at least period correct.

Here is something I found that I might use instead of the OEM distributor.
Looks like OEM but has tuning capabilities.

http://www.123ignition.nl/brand/BMW.html
 

DerSchwede

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Hey that's great Chris I am doing the same thing this winter.
Already have a 3.5 in the car and I'm going to go NA with side draft Webers, cam, pistons and headers. Rounding up parts.
Got a B35 head I am taking to have pressure tested today.
It will look at least period correct.

Here is something I found that I might use instead of the OEM distributor.
Looks like OEM but has tuning capabilities.

http://www.123ignition.nl/brand/BMW.html
Interesting - I'm doing the same but with a high comp Euro B34 (tripple 45ers + custom airbox, Schrick 284, Hartge header) Though I'll use an original BMW distributor with an altered curve. Will be nice to see how our projects end up next spring.

Cheers
A
 

DerSchwede

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Which differential do you like with that engine Herr Schwede?
My first choice will be the standard 3.45:1 with 40% LSD as I have some good units in stock. I'll try that first together with a normal OD 5-speed. Does it make sense to you?

Pairing it with a dog-leg box doesn't make any sense to me since I assume the engine will have enough torque and should work for holiday drives as well as track days. If that should not be the case however, I'll try a 3.07 LSD with a dog-box.
 
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HB Chris

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Sven,

Paul added metal around sides of stub inlets and then opened them up. On the C runners my son ground off the bosses, welded the stud hole and I will have to ask how he got them to match the original finish.
 

DerSchwede

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Sven,

Paul added metal around sides of stub inlets and then opened them up. On the C runners my son ground off the bosses, welded the stud hole and I will have to ask how he got them to match the original finish.
Maybe sand-blasting?
 

sfdon

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I like the 3.45 first but wonder how a 3.25 would be on a good build engine like yours.
Probably depends on what kind of driving you do- in town or open roads.
 

m5bb

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A bit of adult ADD going on here, we've got about three different threads going!


I am curious to hear how well this works.
Boy ain't that the truth as they say in Georgia.

It will be a while before I know if I go this way. $$$
I want to keep the stock look but want the modern dependability.

Maybe we should divide this thread up into two or three new ones. :lol:
 
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