what modifications do you have to make to the M30B35 fuel rail as well as the brontosaurus ribs manifold and do I need a diferent air filter box?

E9inCostaRica

E9inCostaRica

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Hello gentlemen and greetings again from Costa Rica, I have purchased a M30B35 motor from a 1989 E34 535i as well as a five gear GETRAG gearbox to be put into my 1971 2800 E9; I am no expert on this subject so maybe someone here could answear these 2 questions for me:

1) What modifications do you have to make to the motronic fuel rail as well as the brontosaurus ribs manifold in order to fit and fix these 2 together? (could anyone share some pictures?)
2) Using the original manifold as well as the air flow sensor from the M30B35, does the original air filter box that as well as the bracket still fit well or do I need another type of air filter?

Thank you gentlemen in advance for your help in this matter.
 
several questions to unpack.
1. fuel rail - there are several fuel rails that you can use, but most people use the ones from L-jet or early motronic from early e24 / e12. there are 2 types, the large diameter 'J' tube and the thin tube 'race track oval' style. the new square section fuel rail may be possible, but that is outside of my knowledge.

2. the 'C' tube manifold works fine with both types used on the e12 / early e24 fuel rail. the air box from the e12, e24 or e28 all work with the 'C' tube intake and the later type of manifold. the CSi / CSL air box will also fit but it is harder to install unless you have the support bracket. if you are in need of the e12, e24, e28 air box, i have a good one with new filters (3) and the airbox has been recently powder coated in satin black.

3. air flow meter (AFM) - that depends on what injection system you are using. if you are using motronic or L-jet, you will need the AFM. if you are using megasquirt, you do not.
 
Thank you RSPORSCHE for that quick response, your information helps a lot. I am unsure what fuel rail that came with the M30B35 motor but I will take a picture of it and post it here so that you may please see it and let me know if it will fit.
 

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This is Monterey Car Week.
Many of us are slammed getting our cars to Legends.

You need to be very clear on what you are asking....

"2) Using the original manifold as well as the air flow sensor from the M30B35, does the original air filter box that as well as the bracket still fit well or do I need another type of air filter?"

Did you have a Csi? Which original manifold are referring to?
If you did have a Csi- the Plenum will not work on your conversion

show us pics please.
 
Hi Sfdon, those are very fair questions and I apologise for not having cleared these from the get go.

1) the car is a E9 2800 CS and started out as a carburated car with a 4 speed manual transmision , nonethess when I purchased the vehicle the last owner gave me the carbs in a box as he had tried to set it up as a fuel injected car with some alterations including a "vertical" 3.0 manifold complete with fuel rail.

2) I decided to take all that out and upgrade to a 3.5 (M30B35) motor as well as a GETRAG 5 speed manual transmision, but would love to get the look of the 3.0 CSI motor when I open the hood, in other words to keep it looking more like an original E9, so I purchased the C tube manifold commonly seen on these cars, as well as the 3.0 CSI air filter box and the bracket from you.

3) fast forward to now : So now I have learned that the fuel rail from the 3.5 (M30B35) motor will not work on the C tube manifold, I would need to get a e12 or e24 one.

4) Furthermore unless I change my computer to a Megasquirt EFI ECU I have to use the AFM and air filter box and from an e12 or e24 instead of the original e9 air filter box. because it simply will not fit (is this true?).

So I am left with many questions:

a) If I get the fuel rail from the e12 or e24 will it be compatible with the rest of the M30B35 including the ECU?
b) If I get a small MAF sensor in order to fit the original air box will it work in lieu of the AFM?

What would you recommend? And BTW I am in no hurry or rush so if you want to answer after Monterey car week it would be fine to Don.

Thank you in advance pal.
 
a) Absolutely
b) just use the e12/e28 airbox. It has a bracket that sits on the valve cover and holds the AFM. And use the e12/early e24 stub manifolds to mount the C tubes and large plenum
 
Sending pics of part of my inventory Don
 

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found this picture in the web with the fuel rail and metal oval brackets plates that hold the part to the manifold. Does anyone here have the fuel rail available (e12 or e24) with the metal plates?
 

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Looks like the B35 engine is definitely Motronic. The square section fuel rail and the black cover on the AFM are indicators. You can definitely run the C-tube intake. Not sure if the square fuel rail will fit, but probably worth a try before searching for an older one. My concern is actually the distributor. If your engine is the very dirty one shown, you are OK. The later Motronic distributor is controlled directly by the Motronic ECU. The timing is set by the flywheel and or balancer sensors and the ECU works out the advance curve. Not sure if Megasquirt supports that. L-Jet definitely doesn’t. You can ID the Motronic distributor because it is driven directly by the camshaft, so it sits at the end of the timing case instead of fitting into a hole on the side of the timing case.
 
Hi Scott, I do have the distributor from the M30B35, the picture of the motor that I had sent is the old 2800 CS motor with the tower manifold. The new motor (m30b35) is all in parts still and needs to be put together.
 
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Interesting timing , I am currently modifying a B35 fuel rail to fit in the Vintage style manifold for my motronic conversion , I made some brackets to hold the rail into the manifold that bolt into the injector plates bolt in , I modified the manifold for the later injectors to fit , and it appears that last piece of the puzzle will be an adj fuel pressure regulator that is remotely mounted so that the c tubes clear . I wont know for a few more months if what I did works but I feel preety good about what I have done
 
bdigel said:
Interesting timing , I am currently modifying a B35 fuel rail to fit in the Vintage style manifold for my motronic conversion , I made some brackets to hold the rail into the manifold that bolt into the injector plates bolt in , I modified the manifold for the later injectors to fit , and it appears that last piece of the puzzle will be an adj fuel pressure regulator that is remotely mounted so that the c tubes clear . I wont know for a few more months if what I did works but I feel preety good about what I have done
Click to expand...
Hi could you post some pics of your work here?
 
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