Some concerns after putting m3 cams in my m50

[JGood]

A bad Vanos unit would cause a loss in low end torque. This is probably what you're experiencing.

That is exactly how my car felt for 6 months, until I finally got the vanos replaced.

The moment I got my cams put in, the car was fantastic. It pulled hard until 4k, then pulled even harder paster 4k.

Having the bad vanos made me hate my car until I finally got it fixed.

Seems weird that my vanos would work perfectly for a year and 20k miles since I've done the swap, then when I put my cams in, be bad....

Quick question, once you buttoned everything up, did you turn the motor over by hand a to make sure everything was still lined up?

I did not, and this is something I will do when I put the new discs on this weekend. I actually just saw that part of the write-up earlier today.

[M-technik-3]

Fredk is hooking me up with the newer style stop plates and diaphragm. Looks like I'm tearing it all back apart and doing it again. Yay!

Practice makes perfect.

[trackbball21]

[QUOTE=JGood;1814329]Seems weird that my vanos would work perfectly for a year and 20k miles since I've done the swap, then when I put my cams in, be bad....


It's because of the cams I believe. I was reading somewhere on the Beisan Systems site that when installing new cams, it can cause the vanos to go bad for some reason or another. It's related to the higher performance cams, that's all I remember.

My vanos went bad shortly after I got the cams put in. I'd say maybe a week later, not as short as yours though.

[Wh33lhop]

Seems weird that my vanos would work perfectly for a year and 20k miles since I've done the swap, then when I put my cams in, be bad....

Yeah, you'd think it's weird, but you know how this shit works. As soon as you do anything major to your car, something breaks at the same time for no reason.

[moatilliatta]

A lil OT but

It pulled hard until 4k, then pulled even harder paster 4k.

Having the bad vanos made me hate my car until I finally got it fixed.

So would you say you got more low end torque with the s52 cams?

Im doing a little research for twin cam build.

Is there any dyno charts around of twin cam motor variances?

[FredK]

Practice makes perfect.

Yeah. I installed a slightly distorted water pump gasket on an M20. It leaked.

Ugh.

[trackbball21]

A lil OT but




So would you say you got more low end torque with the s52 cams?

Im doing a little research for twin cam build.

Is there any dyno charts around of twin cam motor variances?

I would say it pulled the same as before, up until 4k. from 4k onwards, it continues to pull all the way to 7k I would say. I don't think I gained any low end torque though. Definitely a great upgrade on an m50. I wish I had an m52 though.

On Bimmerforums, there is a whole sticky thread in the e36 section with Dyno's of all different setups.

[Wh33lhop]

Yeah. I installed a slightly distorted water pump gasket on an M20. It leaked.

Ugh.

Hahaha, my water pump gasket was in perfect condition. But I didn't use silicone and I left a trail of coolant everywhere I went for awhile. Looks like the M50 coolant system doesn't have any leaks (it better not), so not carrying a 2.5 gallon jug of distilled water everywhere I go will be nice.

[JGood]

Here is an article from Beisan Systems with more info then you could possibly want regarding the newer style stop discs. It has info regarding why you want them, what is involved, and how to do it.

http://www.beisansystems.com/procedures/single_vanos_diaphragm_spring_procedure.htm

Also, as someone else mentioned in this thread, Beisan has another article which states this:

Performance cams like the cams on the M3 or aftermarket performance cams (Schrick/Sunbelt) create stronger camshaft lash forces and thus are more susceptible to causing a rattle.

(See here for the full article on Vanos rattle: http://www.beisansystems.com/procedu..._procedure.htm)


This is what I'll be doing this weekend to try to cure my Vanos rattle. I do not believe my Vanos went bad while it was removed for 2 days while I did this cam swap. I'm not saying it couldn't happen, but I'm not ready to spend $250 on the Dr Vanos kit just yet. And I'll probably try the Beisan seal kit before I replace the Vanos, if this doesn't work.

[JGood]

And it looks like BMW released a service bulletin on this:

http://www.meeknet.co.uk/E38/Vanos.pdf

[JGood]

I took the car for an extended drive tonight and actually got on it a bunch of times and came up with some conclusions:

1. My vanos is not functioning properly. It is very very laggy and powerless below 4k or so, and surges, just like what malfunctioning vanos systems seem to do.

2. The rattle is present up until about 4k, where it is either drowned out by the exhaust or fades away. I don't know if this is a function of the vanos being bad or the spring plates. I am putting both the spring plates and a Beisan seal kit in on Saturday, so we will see.

3. The rattle is accompanied by a loud intake sound. It's that very deep suction sound that ricers always have with big intakes, but BMW's never seem to have. I'm guessing this is due to the aggressive cams matched with improper timing since vanos isn't working? It's only below 3k or so, then engine noise takes over.

4. This thing is a fucking monster above 4500. I never thought an otherwise-stock cammed m50 would pull that hard. It just keeps pulling, the whole way to 7k. If I can get all these issues straightened out, then this cam swap was worth every penny, and I'd recommend it to anyone.

[dude8383]

Wait till you fix the Vanos man...its going to pull everywhere :)

[JGood]

Wait till you fix the Vanos man...its going to pull everywhere :)

Well, it was working fine before I removed it, so I'm assuming it will be about the same as it was before. From what I understand the cams don't do anything below 4k. I was a little rough removing the vanos as I didn't loosen the 4 exhaust cam sprocket bolts (don't ask...) so I bet I ruined the seal on the piston.

I will report back with my findings and some video's. I did a 0-100 video with the m50 cams, so I'll do one with the s50 cams and compare them.

[BenM]

Sucks you have to take everything apart again, but sounds like it was worth the work. A guy from another board with an E36 track car described the M50 w/ S50 cams almost like a mini S38. I've had a set of S50 cams for about 1.5 years and still haven't installed them in my M50TU.

There's a lot of conflicting info out there, but out of curiosity did you need any other corresponding S50 parts to install these?

[JGood]

There's a lot of conflicting info out there, but out of curiosity did you need any other corresponding S50 parts to install these?

You don't NEED anything.

But I'd highly recommend the upgraded spring plates if your m50 is pre-3/95 (see post #3), and the Beisan Systems seals while you have the vanos out.

I also just noticed you can rent the tools from Beisan for $30.

You need the cam lock tools, the tensioner tool, the vanos turning tool, and you might want the flywheel lock tool if you are using an m50 flywheel (doesn't work with m20 flywheel). I had no trouble keeping my crank at TDC throughout the process. There is no force acting upon the crank so I'm not sure why you would need it. You can also see the TDC mark on the block perfectly with the radiator and grilles removed.