Vanos vs. non-Vanos, Pros and Cons?

[Edham]

I did a search on Vanos for M50 engines. Everything I read seems to give the vanos engines an advantage over non-vanos engines. However, several posts by owners of non-vanos engines seem to contradict the technical informantion. Many non-vanos owners write that there cars are superior.

What are the advantages and disadvantages of vanos m50 engines?

[E36_M_Power]

Same question I've got!!

[Tommy R]

In my searches for the same answer, I understand that the VANOS cars have more low end grunt, possibly more mid-range, and the same peak hp as the non-VANOS cars.

I've heard the non-VANOS cars have more aggressive cams that peak higher in the revs. They also have double valve springs to accommodate the more rev-happy nature of the motor (a good thing). Non-VANOS cars don't have knock sensors, though.

Ultimately, I don't think it'd make much difference in every day driveability, especially if you like to play in the 3500+ rpm range. That was my conclusion when I sold my '93 325is and picked up a (non-VANOS) '92 325is. I'm happy with the '92 and I don't think the power difference is very dramatic. The '92 is stock and the '93 had bolt-ons, though. That'll change. :)

Tommy

[Edham]

It looks like the vanos engines are better?

[Fraser]

"...It was known for being very robust, with double valve springs, strong valves, beefy connecting rods and camshafts so hot that a little rumptyness at idle was not uncommon. However poseurs complained about the idle, and the lack of knock sensors meant mandatory high-octane gasoline and carbon build-up problems as the engine ages. The fix is a regular use of a good gasoline additive. " - European Car, E36 buyers guide- March 2003.

If you really like to rev out the motor, a non-Vanos would be a lot of fun.

"...Unfortunately, gone were the sexy double valve springs and hot camshafts. And while VANOS improved torque throughout the rpm range, the motor was now clearly out of steam by 6000rpms, in sharp contrast to the one it replaced."
-European car, same article, in regard to m50TUb25. (VANOS motor)

I think the non-Vanos motors are cool. :buttrock

[Tommy R]

Originally posted by Edham
It looks like the vanos engines are better?

Without specifically stating the intended use, I'd avoid saying one is "better" than the other. For road racing, I'd lean toward a non-VANOS car since you're more than likely always in the powerband and the double valve springs are nice. For street driving, a VANOS car would provide more low/mid range grunt to make your commute more enjoyable, but at the expense of some power up top. For autocrossing, I think I'd prefer a VANOS car, but it likely wouldn't make a difference.

FWIW, I'm an autocrosser and my car is a true daily driver and I have a '92 non-VANOS. The main reason, however, being that I got a really good deal on it. I would've preferred a VANOS car, but now that I've got the '92, I'm quite happy with it. It does need a chip, however, 'cause it's still pulling strong when it hits the 6400 rpm rev limiter. I need to bump that up to 7k or so.

Tommy

[Daved]

If you get a VANOS engine, you can fit both US M3 cams :)

[Fraser]

Originally posted by Tommy R
Without specifically stating the intended use, I'd avoid saying one is "better" than the other. For road racing, I'd lean toward a non-VANOS car since you're more than likely always in the powerband and the double valve springs are nice. For street driving, a VANOS car would provide more low/mid range grunt to make your commute more enjoyable, but at the expense of some power up top. For autocrossing, I think I'd prefer a VANOS car, but it likely wouldn't make a difference.

Tommy

Well stated.

I might add that even a non-VANOS m50 is still going to have a ton more torque than most cars in its' category...
Coming from my m42, any m50 feels like a beast to me...

[Tommy R]

LOL... Coming from a history of American pony cars, even M3's feel like torqueless wonders to me. :12: Everything's relative, I suppose. :)

I have to say, though, that I don't miss the power. Everything else about the car is so much better that it more than makes up for it. :clap:

Tommy

[E34 Lives]

This is a pretty old tread that I have run across a few times and I always wonder what was the main objective of the BMW engineers with incorporating VANOS, was it designed for smoother running engine performance and just happen to improve on emissions as a by product or was it the other way around, address emissions and by product a more smoother running engine?

The non VANOS engines like the M60B40 ran pretty smooth and had great power even without this design which leads me to believe that addressing emissions was more of a priority.

From a maintenance standpoint point it made the engine less reliable as the VANOS is an additional failure point that occurs around 50K miles.

Ask any owner faced with paying for fixing a failed VANOS on their BMW, if they wish they had a non VANOS engine that avoided this costly issue completely. Would they still choose the VANOS engine design?

My M60B40 has 210K miles, that would have been at least four VANOS repair/maintenance cost at the 50K miles maintenance interval.