Some concerns after putting m3 cams in my m50

[JGood]

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

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

[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.

[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.

[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.

[FredK]

Practice makes perfect.

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

Ugh.

[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?

[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.

[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.

[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.

[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.

[dude8383]

I took it for another drive tonight. The rattle is at idle and up til about 3k, and it does it while reving up or while it's reving down.

I also think there is a significant loss of power below 4k. I can stomp it in 1st gear at 2500 and it will accelerate, but nothing like it used to. I used to be able to break the tires loose by stomping on it like that. now it just kinda putts up to about 4500 then takes off. I also noticed some backfire popping while decelerating.

The increase in power above 4500 is very noticeable, and it pulls the whole way to 7k very hard. It feels like what aftermarket cams would do... not what stock s50 cams would do (yes, these are stock s50 cams, I verified with measurements).


I'm 90% sure my timing is right. I followed the pelican article, used the tools, etc. I aligned the main exhaust sprocket so the holes in the cam gear were to the left of the slots, then put in the dummy tensioner and hand tightened it. I put the intake/exhaust sprockets on so that the slots were centered over the cam holes, and turned that chain the whole way to the left and right to ensure the exhaust cam holes stayed in sight in the exhaust sprocket slots, and they did. I then put the upper tensioner back on, and used the vanos tool to turn it clockwise. I then installed the vanos on the first possible tooth, and turned the vanos tool counterclockwise to draw the vanos gear in, which it did. I tightened the exhaust cam bolts, and that was that. Is this correct?

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

Bentley:

Turn over engine by hand at least two full crankshaft rotations. Reinstall camshaft locking tool and flywheel locking tool to make sure all adjustments are correct. If settings are correct, remove locking tools.

[e30polak]

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

[trackbball21]

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.

[JGood]

I took it for another drive tonight. The rattle is at idle and up til about 3k, and it does it while reving up or while it's reving down.

I also think there is a significant loss of power below 4k. I can stomp it in 1st gear at 2500 and it will accelerate, but nothing like it used to. I used to be able to break the tires loose by stomping on it like that. now it just kinda putts up to about 4500 then takes off. I also noticed some backfire popping while decelerating.

The increase in power above 4500 is very noticeable, and it pulls the whole way to 7k very hard. It feels like what aftermarket cams would do... not what stock s50 cams would do (yes, these are stock s50 cams, I verified with measurements).


I'm 90% sure my timing is right. I followed the pelican article, used the tools, etc. I aligned the main exhaust sprocket so the holes in the cam gear were to the left of the slots, then put in the dummy tensioner and hand tightened it. I put the intake/exhaust sprockets on so that the slots were centered over the cam holes, and turned that chain the whole way to the left and right to ensure the exhaust cam holes stayed in sight in the exhaust sprocket slots, and they did. I then put the upper tensioner back on, and used the vanos tool to turn it clockwise. I then installed the vanos on the first possible tooth, and turned the vanos tool counterclockwise to draw the vanos gear in, which it did. I tightened the exhaust cam bolts, and that was that. Is this correct?

[JGood]

Luckily the job isn't TOO bad, just sucks to do it in cold weather!

I'm in my big heated garage

I just don't like tearing apart a motor. So many things can go wrong. The first time I did it, the big bolt at the top of the vanos, where the ground wire and engine lift loop are, broke. So now the rest of the bolt is stuck in the head. I tried getting it out with a pliers and it just mangled the bolt. The head is somewhat thin there so I just gave up before cracking the head. Now it leaks in that area between the head and the timing cover since there are no other bolts up in that corner. I guess I'll try some RTV sealant?