Exhaust options-M30B35 conversion

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Blaise
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Exhaust options-M30B35 conversion

Post by Blaise »

Damn, I hit a bit of a set back in the completion of my car.

My stock 1980 528i exhaust system does not fit.

My car came with thermo-reactors, so I did not plan to reuse the exhaust manifold and down pipes.

I kept the system from my 1980 528i parts car. It is in decent shape with a new catalytic converter.

My M30B35 motor came out of a 1990 E32[/b], so I am told. The exhaust manifolds looked just like those on my 1980 528i, so I left them on. BUT, they are slightly different and the 528i downpipe flanges do not align. It appears to only be the triangular flanges that would need to be rotated for it to bolt up. I am making this assumption based on my perspective from under the car, seeing that the pipes seem to come into the manifolds at the correct angle.

<table><tr><td><a href="https://picasaweb.google.com/lh/photo/A ... site"><img src="https://lh3.googleusercontent.com/-Y97i ... G_2831.JPG" height="640" width="480"></a></td></tr><tr><td>From <a href="https://picasaweb.google.com/1030509870 ... site">1977 530i upgrades</a></td></tr></table>

I tried to look up exhaust manifolds in www.realoem.com (to compare bavaria to E12), but it seems that E12’s only show the single down pipe version. My 1980 528i exhaust has two separate down pipes.

The whole system is 1.5” (38mm) inner diameter, which I understand to be on the smaller side for my new motor.

So, what are my choices here?

1. Find a set of E12 exhaust manifolds. Unfortunately, I had them on my 1980 528i, but sent them to the metal recycler with the motor. It seems backwards to spend money on small diameter exhaust parts.

2. Cut my down pipes just below the flanges, rotate them to fit, re-weld. I am set up to weld, so this is not a huge deal. But it will take time to do it right.

3. Get a set of headers. If I am going to cut and weld, I thought I might want to consider getting some free flowing headers. Would this be a problem with the smogging in California? What are the header options for our E12’s.

Some header sources I found on the web (no shipping or tax in prices):

Ireland Engineering ($585):

http://www.nexternal.com/ireland/m30-ex ... -p550.aspx

http://www.vintagebmwsource.com/e24-e28-exhaust

http://www.ebay.com/itm/New-BMW-E9-E12- ... 702wt_1398

Stahl ($1,032):

http://www.stahlheaders.com/Frame%20New%20RR.htm

Paeco ($420, plus $180 coat):

http://www.paeco.com/Extractor%20Exhaust%20Headers.htm



Thanks guys for all of the help and support. I am getting much closer to a running car.

Cheers,

Blaise
Last edited by Blaise on Wed Sep 09, 2015 11:58 am, edited 1 time in total.
1977 BMW 530i
1973 R75/5 BMW (motorcycle)
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John in Simi Valley
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Post by John in Simi Valley »

Blaise, I'd be most concerned about passing California emissions. The motor is a Euro M30B34 "from a Bavaria". As you know -- Bavarias never came with a B34. More likely the motor came from a Euro 535i/735i circa '84-87. To weird things our further; you're using a 1990 B35 wiring harness. I'm 98.7% sure the SMOG technitian will be going by whatever the computer says a 1977 530i should be. Chances are on the visual inspection they will have no clue if the car is missing the thermal reactors but may very well inspect for a CAT. I suggest accomodating them. Install a Motronic with O2 sensor and CAT.

As far as your down pipes are concerned, you are capable of doing magic with the welder, just take the 2 hours to fixture everything together, tack weld it really well and take another hour to disassemble and weld the sucker properly. The air flow of a two-pipe system is very efficient, nearly as good as headers. The nice thing about stock systems with the slight back-pressure is the added torque you'll experience in performance. The top end may suffer a bit, but so-what unless you're specializing in quarter mile drag races. This is a BMW. Try to adapt the '80 exhaust and be done with it.

Just my 2 cents.
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anthony
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Post by anthony »

Emissions. The referee is going to look at the year of the engine and everything that went with it. So you will need a cat and a 02 sensor. Custom headers will not pass.

With my m30b34 I took the manifolds and the down pipes off the e28. The muffler guy joined the pipes at the e12 cat and put a port for the 02 sensor.

When I convert to b35 I am going to keep what I have and convert to the b35 manifold and down pipes at a later date. Because you can do the welding you should do it now.
Anthony
1980 528i 3.5 M30B35 motronic 1.3
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Blaise
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Post by Blaise »

Thanks Anthony and John.

Like you said, I don't mind doing some fabrication and welding. It was not what I had planned, but I enjoy that kind of work.

I will be installing a catalytic converter, as well as the 4 wire oxygen sensor needed for the motronic 1.3.

In terms of smog, my plan was to visit the referee and let them know that I have installed a motor out of a 1989 735i. While this would be an M30B35, it has nearly the same specifications as my motor, and all of the sensors would be correct. They should then smog it based on the 1989 car and re-sticker my car accordingly. It is my understanding that this process is encouraged and cost about $10.

I like the idea of using later manifolds and I will look into that.

Last question. Is there a reason to believe that I will not pass smog if I use a set of shorty headers, with catalytic convertor and oxygen sensor?

Thanks again.
1977 BMW 530i
1973 R75/5 BMW (motorcycle)
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Eddie in TO
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Post by Eddie in TO »

Blaise,
Would you be interested in a custom twin 2" stainless steel exhaust incl. ceramic coated long tube Stahl headers that came off my 2.8 M30? If so, PM me.

Comes with a Stebro rear muffler, Stebro resonator, hi-flow 2-in-2-out Magnaflow catalytic converter finished with two classy resonated Brullen polished tips. It’s still in one piece (after the headers) therefore I'd have to cut the exhaust for shipping purposes but I would mark the tubes first to help with your assembly.
Eddie Ribeiro
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Post by Mike W. »

Blaise wrote:Thanks Anthony and John.

Like you said, I don't mind doing some fabrication and welding. It was not what I had planned, but I enjoy that kind of work.

I will be installing a catalytic converter, as well as the 4 wire oxygen sensor needed for the motronic 1.3.

In terms of smog, my plan was to visit the referee and let them know that I have installed a motor out of a 1989 735i. While this would be an M30B35, it has nearly the same specifications as my motor, and all of the sensors would be correct. They should then smog it based on the 1989 car and re-sticker my car accordingly. It is my understanding that this process is encouraged and cost about $10.

I like the idea of using later manifolds and I will look into that.

Last question. Is there a reason to believe that I will not pass smog if I use a set of shorty headers, with catalytic convertor and oxygen sensor?

Thanks again.
Starting from the begining, Bavs did use manifolds that looked like B34 manifolds, but with the flange twisted some and a slightly different angle.

If you go to a referee you will need everything an 89 would have, including later type of evap, maybe a CEL and probably have to pass 89 emissions levels. They go over it very carefully. Headers of any type would be out of the question. If everything is perfect and it smogs clean, it is inexpensive, but a big if.

E12 528i's came with the single downpipe, all of them, so if you had dual downpipes it wasn't original. That may or may not fly past the smog guy, but probably not the referee.
Mike W.



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Blaise
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Post by Blaise »

Thanks for the information Mike.

I got a little excited about the idea of headers, but I now understand that it is out of the question to pass smog in California. From what I gather, a set of headers can be accepted if they have a CARB (California Air Resources Board) exempt status. To get this, a manufacturer has to apply for it and prove that their headers do not increase pollution over the stock set up. It sounds like an expensive process which most E12 parts suppliers would be unlikely to go through. It does not matter if the car passes emissions test with the headers, they must have CARB exempt status.

As for my 1980 528i not having stock E12 exhaust, I wonder what it did have. Here is a photo of the motor with exhaust manifolds:

<table><tr><td><a href="https://picasaweb.google.com/lh/photo/C ... site"><img src="https://lh5.googleusercontent.com/-6723 ... C_0823.JPG" height="425" width="640"></a></td></tr><tr><td>From <a href="https://picasaweb.google.com/1030509870 ... bsite">M30 exhaust</a></td></tr></table>

I am going to stick to stock for now.
1977 BMW 530i
1973 R75/5 BMW (motorcycle)
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Eric Q
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Post by Eric Q »

Is there any reason why you couldn't use b35 exhaust manifolds? Especially since you are telling them you are using a b35 engine. I have those manifolds on my Euro b34 engine (it's in an E23...).

As long as the Euro engine doesn't have any major modifications like a hot cam and you have a good catalytic converter you should be able to pass the sniff test. I have a port and polished head and E36 M3 cats and have no problem...

As for the visual, well...maybe you can find a "friendly" smog shop...

Somebody could chime in on this, but I might see the stock 528i catalytic converter as being a little restrictive in this application. While it would work in passing smog, performance wise I would prefer something bigger. HOWEVER, going by the book, if you go to a referee I'm guessing they would either want to see a stock cat (maybe you could use an E32 one?) or an aftermarket approved version (they have serial numbers on them) of which there is a very limited selection (dual 2" in, single 2.5 out).

I make this comment because of my experience...I have the E36 cats, dual 2" midsection with mufflers on each side and ran dual 2.25" in/single 3" out rear muffler. It ran GREAT but due to the rear muffler with large diameters it was loud. I swapped it all out for a Euro 733i midsection and rear muffler. Quiet but noticeably slower at the mid range/top end. I will be going back to the dual 2" mid section but use an OEM 745i rear muffler and expect to get most of the performance back.

Using an aftermarket cat and 2.5" mid section and rear muffler may be a good compromise...I'd expect it would still flow better than a stock 528i exhaust.
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Post by Peter Florance »

Eddie in TO wrote:Blaise,
Would you be interested in a custom twin 2" stainless steel exhaust incl. ceramic coated long tube Stahl headers that came off my 2.8 M30? If so, PM me.

Comes with a Stebro rear muffler, Stebro resonator, hi-flow 2-in-2-out Magnaflow catalytic converter finished with two classy resonated Brullen polished tips. It’s still in one piece (after the headers) therefore I'd have to cut the exhaust for shipping purposes but I would mark the tubes first to help with your assembly.
Hijack; Eddie, your Stahl headers have 2" secondaries?
Peter Florance
First Fives.Org - The E12 Registry
1981 E-Street Prepared Euro BMW 528i w/3.5L & Megasquirt Fuel Injection
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Blaise
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I made it all fit

Post by Blaise »

Well, it all fits now.

Here are the crusty old downpipes:

<table><tr><td><a href="https://picasaweb.google.com/lh/photo/F ... site"><img src="https://lh5.googleusercontent.com/-WR7G ... G_2909.JPG" height="300" width="400"></a></td></tr><tr><td>From <a href="https://picasaweb.google.com/1030509870 ... site">1977 530i upgrades</a></td></tr></table>


A little wirebrushing:

<table><tr><td><a href="https://picasaweb.google.com/lh/photo/A ... site"><img src="https://lh5.googleusercontent.com/-LyVL ... G_2913.JPG" height="400" width="300"></a></td></tr><tr><td>From <a href="https://picasaweb.google.com/1030509870 ... site">1977 530i upgrades</a></td></tr></table>

Cut the flanges:

<table><tr><td><a href="https://picasaweb.google.com/lh/photo/v ... site"><img src="https://lh3.googleusercontent.com/-e_Jr ... G_2918.JPG" height="300" width="400"></a></td></tr><tr><td>From <a href="https://picasaweb.google.com/1030509870 ... site">1977 530i upgrades</a></td></tr></table>

Temporary install onto the exhaust manifolds:

<table><tr><td><a href="https://picasaweb.google.com/lh/photo/p ... site"><img src="https://lh4.googleusercontent.com/-pcQI ... G_2924.JPG" height="300" width="400"></a></td></tr><tr><td>From <a href="https://picasaweb.google.com/1030509870 ... site">1977 530i upgrades</a></td></tr></table>

Tack weld fitment check:

<table><tr><td><a href="https://picasaweb.google.com/lh/photo/p ... site"><img src="https://lh3.googleusercontent.com/--QnL ... G_2943.JPG" height="300" width="400"></a></td></tr><tr><td>From <a href="https://picasaweb.google.com/1030509870 ... site">1977 530i upgrades</a></td></tr></table>

Weld one:

<table><tr><td><a href="https://picasaweb.google.com/lh/photo/3 ... site"><img src="https://lh4.googleusercontent.com/-o7e_ ... G_2965.JPG" height="300" width="400"></a></td></tr><tr><td>From <a href="https://picasaweb.google.com/1030509870 ... site">1977 530i upgrades</a></td></tr></table>


Weld two:

<table><tr><td><a href="https://picasaweb.google.com/lh/photo/3 ... site"><img src="https://lh4.googleusercontent.com/-f0Bp ... G_2968.JPG" height="400" width="300"></a></td></tr><tr><td>From <a href="https://picasaweb.google.com/1030509870 ... site">1977 530i upgrades</a></td></tr></table>

Paint preparation:

<table><tr><td><a href="https://picasaweb.google.com/lh/photo/E ... site"><img src="https://lh5.googleusercontent.com/-_B7q ... G_2971.JPG" height="300" width="400"></a></td></tr><tr><td>From <a href="https://picasaweb.google.com/1030509870 ... site">1977 530i upgrades</a></td></tr></table>

Painted with POR15 exhaust manifold paint:

<table><tr><td><a href="https://picasaweb.google.com/lh/photo/V ... site"><img src="https://lh6.googleusercontent.com/-9bWZ ... G_2976.JPG" height="400" width="300"></a></td></tr><tr><td>From <a href="https://picasaweb.google.com/1030509870 ... site">1977 530i upgrades</a></td></tr></table>

http://www.por15.com/FACTORY-MANIFOLD-G ... info/FMGH/

Now I need to find the replacement gaskets and install this whole thing.
1977 BMW 530i
1973 R75/5 BMW (motorcycle)
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