M50 Manifold, Dipstick, Fuel Rail and M52 TB - Vacuum Lines!?

[BBDirtbiking]

Background: M52 motor, M50 manifold, E34 M50 dipstick, M50 fuel rail, M52 valve cover, M52 throttle body.

So how I currently have my vacuum lines hooked up:

From the back plug on the manifold, my line comes out and goes into a T. One side of the T goes to the face of the PCV, the other side of the T goes to the ICV. From the side of the PCV we have the crankcase breather. The other side of the ICV goes to the intake elbow. This takes care of all the 'larger' vacuum lines. Now the small lines, I had a hose come off the bottom of the PCV and reduce into a smaller hose that then connected to the back plug on the manifold (wrong, no vacuum necessary on this line!). I also had a small hose from the fuel rail to the bottom of the intake manifold, by the IAT sensor.

Now my new proposed setup...


Only problem is the dipstick connection, but that is how it came stock on the M52...


I might just use my M52 dipstick and try to modify it to read the correct oil level.

So what this post is about... Will my proposed vacuum line setup be correct? Or am I missing something, I am having a hell of a time trying to figure this out, and so far this is the most logical.

Please give me some feedback, or some links to a GOOD guide, everything I found is crap for detailing the smaller vacuum lines, the large ones were easy.

[BBDirtbiking]

No one is willing to share their knowledge of M50 manifold swaps...?\

I might delete the PCV/CCV all together. Dunno where I will route the oil to though. Going to probably look into customizing one of my dipsticks.

[ForcedFirebird]

It's best to have crankcase vacuum on your engine for longevity/reliability.

Simplest way is to run the valve cover vent through a catch can and in front of your MAF. This will keep oil vapors off the MAF, not have to worry about vac leaks while having vac on crankcase.

[BBDirtbiking]

So in front of the MAF as to avoid a vacuum leak?

I had always heard to tie it into the ICV on the intake elbow, between the MAF and TB.

I HATE the idea of oil evaporation getting into my intake, not sure how well a catch can would work. I could just use my CCV as a catch can, haha. I have it tied into the intake at the T between the ICV and CCV at the moment. I have it laying down horizontal so I am going to look at making it sit vertical as it is stock.

[pandaboo911]

For OBD1 the VC breather port runs to 2 places. The larger hose runs to a port on the rubber intake elbow, the second much smaller hose runs to a nipple on the ICV hose fitting, just before it enters the intake manifold. The smaller hose is there to maintain a vacuum at idle.

The obd1 VC also has a sort of an enclosed "maze" just before the port to prevent liquid oil from getting through

You're not piping liquid oil into your intake, it's oil vapor. probably better for your engine in the long run, think of it as extra lubrication :)

If you already have the CCV, keep it. It's basically the same thing as a catch can, except the liquid oil goes back into the pan via the dipstick.

[328ijunkie]

http://www.r3vlimited.com/board/showthread.php?t=220778 ;)

oh and on the OBD1 setup PLENTY of liquid oil will end up in your intake manifold. I run the OBD2 setup even on M50 swap cars :D.

[ForcedFirebird]

http://www.r3vlimited.com/board/showthread.php?t=220778 ;)

oh and on the OBD1 setup PLENTY of liquid oil will end up in your intake manifold. I run the OBD2 setup even on M50 swap cars :D.

Sure, if you like oil/water mix going back in your oil pan. The reason for a PCV is to evacuate the oil/water vapor out of the crankcase, why would you want that back in your pan? That's redundant.

[BBDirtbiking]

http://www.r3vlimited.com/board/showthread.php?t=220778 ;)

oh and on the OBD1 setup PLENTY of liquid oil will end up in your intake manifold. I run the OBD2 setup even on M50 swap cars :D.

I ended up doing the same thing!



Do you mind sharing your vacuum line setup? or confirming if mine is correct or not?

[treff-7]

I have the same setup. your drawing is correct except for 1 thing. the port on the firewall side of the intake goes to the FPR without the Y. the port on the short plastic piece with the clip needs to be capped. I did it that way and the engine runs perfect with rock solid idle.

[BBDirtbiking]

So my setup is exactly the same, capped or uncapped the way I have that Y has the same vacuum, good to know!

[treff-7]

you are right. so either/or it should be good.