M50 manifold installation complete

[bmw328]

I've enyone in intrested, If got a 325I M50 manifold that I converted for the use on a 328I For sale.
R500 neg. Including injector cover.
Riaan 073 528 7575 or e-mail me at [email protected]

 

[Major]

Got it now, thanks! :thumbsup: bmw328 what exactly did you do to 'convert' the intake manifold?

 

[bmw328]

The 328I has a "air tempreture sensor" located in the throttle side of the intake manifold, The M50 don't have that sensor. So I had to create a space where it fits into on the M50 Manifold.

 

[Major]

I'm busy doing this swap, I still got a few questions. What did you guys end up doing for a fuel rail? My 328i fuel rail doesn't line up at all to the mounts on my 325i manifold, must I get a 325i rail?

I also noticed now, after doing some measurements, that the difference in diameter between the 325i and 328i throttle body is... 0.762mm. Why go through all the trouble of fitting wider gaskets/mating plates, when they differ by such a tiny amount?

What are A and B for? I'm guessing B is where the IAT sensor goes, so why aren't you guys using it? And A? And should I worry about C? There's the teeny tiniest hole in that first runner where a piece has clearly been broken off.

What did you guys do about the PCV valve? I haven't tried mounting it the engine, but I can already see that it's in a completely different spot from the 328i manifold, and doesn't use the same gasket. Are you guys still using the 328i PCV valve?

What are you guys doing for the supporting brackets? Did you just use the 328i ones? Like I said, I haven't mounted it to my engine yet, so this might turn out to be a stupid question, will the existing mounts rotate to fit D? As you can see, they're different distances apart.

And lastly, what's E?

Sorry for asking so many questions! Please help me out.

 

[kabal]

as far as I know, for the fuel rail you dremel/grind out some of the plastic by the mount, and then you can move the bracket it at an angle and they are able to align.

Not sure on the underside mountings, you might have to make adapter plates???

the manifold I had already had the sensor in B, and I dont actually recall having A, but it was while back.

I am sure slowmo can answer all these

 

[bmw328]

I'm busy doing this swap, I still got a few questions. What did you guys end up doing for a fuel rail? My 328i fuel rail doesn't line up at all to the mounts on my 325i manifold, must I get a 325i rail?

I also noticed now, after doing some measurements, that the difference in diameter between the 325i and 328i throttle body is... 0.762mm. Why go through all the trouble of fitting wider gaskets/mating plates, when they differ by such a tiny amount?

What are A and B for? I'm guessing B is where the IAT sensor goes, so why aren't you guys using it? And A? And should I worry about C? There's the teeny tiniest hole in that first runner where a piece has clearly been broken off.

What did you guys do about the PCV valve? I haven't tried mounting it the engine, but I can already see that it's in a completely different spot from the 328i manifold, and doesn't use the same gasket. Are you guys still using the 328i PCV valve?

What are you guys doing for the supporting brackets? Did you just use the 328i ones? Like I said, I haven't mounted it to my engine yet, so this might turn out to be a stupid question, will the existing mounts rotate to fit D? As you can see, they're different distances apart.

And lastly, what's E?

Sorry for asking so many questions! Please help me out.

You are acctually Right:
The fuel rail don't line up with the manifold, You can use the 328I fuelrail & injector: I acctually bent my fuelrail brackets to slide in. Used large washers to secure it to the manifold. no prob.

* A - Is for your FUEL PRESSURE REGULATOR (On the fuel rail)
- Your 328i manifold has 2 of this units. 1 Fuel pressure regulator,
2nd for Exhaust flap.
* B - Air temprature sensor (FOR the M50 Bosch system, 328i uses
Siemens ECU & sensors. So I blocked this hole off. Had to fabricate
a new hole right between INTAKE RAM 3 and 4, just before after the
Throttle (Thats were the 328i's one is located)
* C - Won't be a problem, exept if the INTAKE RAM's are breached.
(Airleak)
* D - Won't line up, have to make your own, remember you are modifying
a car's manifold that came from a total different era, The whole fuel
fuelinjection system is different. So modify everything, but try to
keep the sensor locations on the same place. It was designed like
that for a reason. Change the manifold, its possible, I didn't like the
Modification at all.
* Lets call it "F" - bacause thats the "F" up on this conversions. The Oil seperator valvue & the idling control valvue have to fabricate your own "plumbing there"

---

O ja, Just to clear something up. There were 2 different models of M50 manifold manifactured! The look identical.
M50B20 - 320i, 520i
M50B25 - 325i, 525i

The M50B25's manifold Intake RAM tubes is alot larger than the 323i & 328i's manifold. And does infact make a huge differens at the top end. So it is worth while.
Check yours, it might be from a 320i

 

[bmw328]

I'm busy doing this swap, I still got a few questions. What did you guys end up doing for a fuel rail? My 328i fuel rail doesn't line up at all to the mounts on my 325i manifold, must I get a 325i rail?

I also noticed now, after doing some measurements, that the difference in diameter between the 325i and 328i throttle body is... 0.762mm. Why go through all the trouble of fitting wider gaskets/mating plates, when they differ by such a tiny amount?

What are A and B for? I'm guessing B is where the IAT sensor goes, so why aren't you guys using it? And A? And should I worry about C? There's the teeny tiniest hole in that first runner where a piece has clearly been broken off.

What did you guys do about the PCV valve? I haven't tried mounting it the engine, but I can already see that it's in a completely different spot from the 328i manifold, and doesn't use the same gasket. Are you guys still using the 328i PCV valve?

What are you guys doing for the supporting brackets? Did you just use the 328i ones? Like I said, I haven't mounted it to my engine yet, so this might turn out to be a stupid question, will the existing mounts rotate to fit D? As you can see, they're different distances apart.

And lastly, what's E?

Sorry for asking so many questions! Please help me out.

You are acctually Right:
The fuel rail don't line up with the manifold, You can use the 328I fuelrail & injector: I acctually bent my fuelrail brackets to slide in. Used large washers to secure it to the manifold. no prob.

* A - Is for your FUEL PRESSURE REGULATOR (On the fuel rail)
- Your 328i manifold has 2 of this units. 1 Fuel pressure regulator,
2nd for Exhaust flap.
* B - Air temprature sensor (FOR the M50 Bosch system, 328i uses
Siemens ECU & sensors. So I blocked this hole off. Had to fabricate
a new hole right between INTAKE RAM 3 and 4, just before after the
Throttle (Thats were the 328i's one is located)
* C - Won't be a problem, exept if the INTAKE RAM's are breached.
(Airleak)
* D - Won't line up, have to make your own, remember you are modifying
a car's manifold that came from a total different era, The whole fuel
fuelinjection system is different. So modify everything, but try to
keep the sensor locations on the same place. It was designed like
that for a reason. Change the manifold, its possible, I didn't like the
Modification at all.
* Lets call it "F" - bacause thats the "F" up on this conversions. The Oil seperator valvue & the idling control valvue have to fabricate your own "plumbing there"

---

O ja, Just to clear something up. There were 2 different models of M50 manifold manifactured! The look identical.
M50B20 - 320i, 520i
M50B25 - 325i, 525i

The M50B25's manifold Intake RAM tubes is alot larger than the 323i & 328i's manifold. And does infact make a huge differens at the top end. So it is worth while.
Check yours, it might be from a 320i

---

E - Is for your idling control valvue, hoses mys be modified to acomodate the oil seperator and the idling control valvue. best is if you have the 325i idling control value hose that fits into the manifold.

 

[SlowMo]

bmw328 answered most of the questions

But lets see what I can add. Firstly you are missing a vital part, a plastic fitting that fits onto the manifold behind the throttle body. You need this so try and get yourself one if you don't have it. It has the '3rd' vac source that you will need as explained below.

ok lets try and simplify it by starting off with the hoses connected to the 328i manifold. There are 3 hoses, two thin hoses and one that is a little thicker.

The 2 thin hoses I believe are for the exhaust flap and the FPR. So join these two hoses with a t-piece or y-piece and connect it to 'A'. Fortunately they are identical diameters so this is easy.

This leaves you with the thicker hose, I joined this to the '3rd' vac source I explained above. Its not a direct fit, the nipple on the manifold fitting is smaller than the hose, so I cut a tiny piece of silicone hose and fitted this over the nipple, effectively making the nipple larger. the hose then fitted perfectly onto it, and I used a cable tie to secure it.

so great, now we have all 3 vac hoses attached to the 325i manifold.

next tackle the IAT. I definitely used 'B' as my mounting point for the 328i IAT sensor. Use a die to make threads onto the 328i IAT sensor and it will screw right in, nice clean install.

so far so good, nothing major, excuse the pun

the rest unfortunately u need to fabricate some plumbing. bascially the 325i manifold has a single large vac source but the 328i manifold has 2, marked 'E' and there is another one unmarked next to it. basically you need to fabricate a hose that plugs into the single vac source of the 325i manifold and then plugs into the oil seperator and pcv valve. once that is sorted then all your plumbing is done.

use the 328i fuel rail but do as bmw328 said or you can make two simple brackets to bolt the fuel rail down.

I didnt bother with supporting brackets for the manifold. I used an L-braket to mount the PCV valve. the 328i supporting brackets cannot be used, so if you want a perfect install, try and get the 325i supporting brackets, but these will have to be modified slightly at the bottom where they bolt onto the block.

about the 325i TB, as far as I know this cannot be used on the 328i, something do do with the electronics? But I'm not sure, maybe someone else can clarify.

last point about the IAT sensor, bmw328 touched on this. YOU HAVE TO USE the 328i IAT sensor. It will be very tempting to use the 325i IAT sensor cos it screws in nicely onto the manifold and it plugs into the harnes beautifully. But the sensors are not the same. The 325i sensor will cause the ecu to run the car leaner than it should which can have bad consequences.

 

[Major]

Let's see if I listen in class.

Fuel Rail
Can fit to the 325i manifold, but it has to bent? Can someone put up pictures of their fuel rail setup? The guys in the States fit the fuel rail no problem, no modification necessary.

Or you can fabricate small backets to go between the rail and the intake.

A
Vacuum source for the Fuel Pressure Regulator, and since I don't have an exhaust flap (or even an E36 ), I won't need a T-fitting or anything.

B
Intake Air Temperature sensor location. I mustn't use a 325i IAT sensor. There seems to be mixed opinions on whether to put the 328i sensor there, or block this off. bmw328 ended up modifying the 325i manifold to put the 328i IAT sensor in the middle of the intake behind the throttle body, SlowMo rethreaded the 328i sensor and used B. Did either of you have any problems with either of these setups?

bmw328 I'd still really like to see pictures of your IAT location. What do you have to do to the manifold to fit it?

D
I'm going to have to modify either the 328i or 325i mounts, as neither of them will perfectly line up. SlowMo didn't bother with the brackets at all.

E
Idle Control Valve vacuum source. But where is the ICV source on the 325i manifold? Do they combine the PCV and and idle control vacuum sources into this big hole under the manifold? Again, I'd really like a pic of how this is done on your swaps, or on a 325i.

SlowMo you didn't end up saying what the 3rd vacuum source was for, or where it can go on the 325i manifold. What is this plastic fitting you're talking about?

What is the nipple (that has a big cap on it) to the left of E for?

Throttle Body
The 325i TB can't be used to something to do with electronics, could you explain? The only electrical component that plugs into the TB is your TPS sensor. I also noticed that there's a nipple on the 325i TB, I presume for another vacuum source, what would this be for? It has a small hole directly in line with the throttle plate.

Thanks for your help guys. I'm a slow learner and ask dumb questions to begin with, I'll get it soon enough. Thanks!

 

[bmw328]

* I wouln't say you cant use the 325I Throttle, you might be able to modify the TPS from the 328i TB to fit the 325i TB.
BUT: The 328I replaced the 325I for a REASON! The 325I's Throttle is a bunch of S@#t. Ignore my french! LOL.
* 325i Used links on its Throttle, It gave enless k@k in its days.
* 328i Throttle uses a sirclar motion of the cable on a pully. Much smoother accelaration. And its s@3t free.

328I Air temprature sensor.
Just remember that me (BMW328) and SLOWMO did't know each other before a few days ago.
* I acctually like his idea of rethreading the m50 thread to work on the 328I IAT sensor much more than my idea.
* I drilled a hole & pradley steeled the shit out of mine. (And no, didn't have any trouble with mine, neather did SLOWMO, He is using his Dailly.

Brackets, What brackets? I didn't use them ether!
* But original 325i Brackets will just work perfect & no need to modify, the M50, M52 block are identical.

Idling control valvue.
* the one big hole you have on the manifold, behind the throttle. thats your ICV's home, it uses a rubber pipe that connects it from the manifold to the ICV.
Please do remember, the 325I NEVER came with a OIL SEPERATOR VALVUE, only a ICV. The breather work totally diffirent on that cars.

Anyway, I did this conversion on 1998 323i, M52. Didn't do me much use, I converted every thing back. Don't own that car nomore, so a pic from my side will be HELL.

 

[InFrA007]

Time to resurrect an old thread...

I've been working on this modification for some time while doing other jobs on my track car and after installation my M50 manifold with homemade ghetto piping, I ran into a small but major problem none-the-less and am hoping somebody can help me before I revert back to the M52 Manifold.

On first startup the car idled pretty rough, coughing and spluttering but not cutting out, I then however tapped the throttle, it then shot up merrily to the redline... and stayed at wide open throttle bouncing merrily on the Rev-Limiter like like an Opel Corsa owner would on cold start... :argh: I took my foot off the pedal immediately (I litterally just tapped it, didn't put my foot anywhere near to flooring it). Now considering the car has been standing for a little over 3-4 weeks and having not actually been driver in 2 months as I have been stripping it for the track... rev-limiter on cold start can in no way shape or form be good for the motor so I pulled the key immediately as soon as it shot to the limiter.

I then re-checked all my piping and cabling to ensure it was all tight and everything seemed good, didnt really make sense why the car did it. I checked the trottle cable on the throttle body for obstructions to ensure that nothing was getting stuck and maybe preventing the spring from pulling back but no, the throttle wasnt stuck.

Now... my theory... maybe I'm wrong but I'm hoping somebody with solid experience/know-how can give me a difinitive answer on this one... the main vacuum outlet on the M50 manifold (the one at the bottom in the middle) has a u-shaped pipe that comes out of it, this pipe has a plastic fitting with a rubber seal and a clip. After further investigation, I see that the clip somehow broke off of mine and I believe that due to this, the pipe is not getting a solid seal and therefore causing a vacuum leak. Could this be the cause of my red-lining?

A mechanic friend told me to start it again, let it idle rough (it only shoots to limiter with some throttle) and try listen around for vacuum leaks... Makes sense to me but I'm so petrified I break the motor at the moment that I don't really want to try that...

I also don't want to replace just that clip and try again only to red-line the ice cold engine again. I'm afraid of damaging the motor so I'm strongly considering going back to the M52 to save the motor and at some point in the future bite the bullet and order the Turner Motorsports Retrofit kit instead of doing the homemade T-Piece/U-Bend/Heater Hose setup as I've kind of lost my faith in either my abilities or the homemade method... or both.

Any ideas/suggestions would be welcome... or anybody know of some PE-Based members who have done this conversion?
:fencelook:

 

[Julz]

It defenately sounds like a Vacum leak.Take the Mechanics advise and check for Vacum leaks but this time let the engine warm by letting it idle before you touch the Throttle Pedal again.Only touch the Pedal when u certain you fixed the leak.It helps to spray a flamable liquid like a Carb Cleaner around the Manifold,if the revs pick up while spraying at a certain spot you know that there is a leak.Be cautious when using the Spray and avoid spraying it directly into the engine or you could have a serious Back fire.Good Luck

 

[InFrA007]

It defenately sounds like a Vacum leak.Take the Mechanics advise and check for Vacum leaks but this time let the engine warm by letting it idle before you touch the Throttle Pedal again.Only touch the Pedal when u certain you fixed the leak.It helps to spray a flamable liquid like a Carb Cleaner around the Manifold,if the revs pick up while spraying at a certain spot you know that there is a leak.Be cautious when using the Spray and avoid spraying it directly into the engine or you could have a serious Back fire.Good Luck

Thanks for the feedback, much appreciated, I've ordered the new clip from the local stealers, I've also been looking at the pipe design from my homemade/makeshift setup and am looking at ways of improving it before installing the new clip as there is tension where I feel there shouldn't be any tension especially considering how crucial the whole vacuum system actually is.

Car is currently at the cage builder until end of next week, once it's back I'll take the throttle-body etc... off again and then install the new clip and piping then start her up and check for vacuum leaks. I like the idea about the Carb Cleaner, thanks! :thumbs: