M50 vanos retrofit???

[Bruno]

I know it has been done:
M50 non vanos head with vanos retrofitted.



I don't know enough about the vanos yet, but would be interesting to do?

[winfred]

you would need the cams and the sprockets/spacers that go with them, and a oil supply for the servo, and a vanos engine wiring harness/computer, this will get you knock sensors too. the vanos unit will bolt right to the head, you just need the support equipment for it

[Geoff Hoad]

Bruno,

For all the trouble there is some benefit to the torque but surely the better investment if you want more power is a D'Sylva chip or M3 cams or both. Effectively drop in parts and lots of power.

Just a thought.

Geoff
'94 525iA

[winfred]

m3 cams are vanos

[Geoff Hoad]

VANOS is the mechanism that controls variable camshaft timing. They are not the actual cams themselves. Cams from an S50 drop right in and do give greater performance but they are different to the standard M50 cams.

Cheers,

Geoff

[winfred]

the front of the intake cam is a different shape then the non vanos to accept the gear on the piston of the vanos unit

[Geoff Hoad]

Very true.

[albundy]

I know it has been done:
M50 non vanos head with vanos retrofitted.



I don't know enough about the vanos yet, but would be interesting to do?

My mechanic has done it numerious times, last one was only a week ago and I was there to witness it. Cams, dme, wirings and etc. Bolt straight on, but you need to shave the head a little to fit the vanos unit. Better torque, power comes in earlier.

Rgds

[Brandon J]

Well, if you are up to the task, go for it. Since this is going to be for a dedicated track car, getting S50 cams instead of the M50tu cams would be much better. When I put the S50 cams in, it gave a little more torque in the mid and a lot of torque int he upper rpms. Of course HP is increased significantly. A stripped e36 and S50 cams is a great combo. The last bit I would look into is just getting a M50tu head as it has better flow due to the valve stems and the valvetrain is lighter. If you do go this route, make sure to use the M3 valve springs and S52 valve retainers.

[Bruno]

I thought that the early M50 heads were better because from what I found:

The non vanos motor has some really hot cams in there. Hot enough that BMW decided that these motors didn't idle all that well and issued a TSB to advance the exhaust cam and retard the intake cam at the expense of top end power in the
event that the customer complained about idle quality.

non Vanos cams are :
INTAKE 240 degrees, 9.7mm lift
EXHAUST 240 degrees, 9.0mm lift

Vanos 2.5L cams are (I think):
INTAKE 228 degrees, I forgot how much lift, but not more that 9.7mm
EXHAUST 228 degreesm 8.9mm lift

Anyways, VaNoS basically just advances the intake cam by a preset number of degrees (its 12.5, right?)
And above x rpm, VANOS shuts off.

So the VaNoS motor will have slightly better bottom end torque.

But after the VaNoS shuts off (Somewhere around the 3.5K rpm range,
I think), the 93 car will be outpulled by the 92 car every time.

Oh yeah, and the non VANOS has 1mm thicker valve stems, dual valve springs (not single ones like the VaNoS cars do), a bigger alternator, and much MUCH bigger and stronger connecting rods.

Drawbacks? a little more reciprocating mass and the lack of a knock sensor.