Can the Vanos system be retro fitted to a Non-Vanos M50 B25?

[Rorty-corty]

As the title asks, can it be done?

Does the Vanos system make a noticeable improvement?

Is it true that the non-vanos engines have a slightly stronger bottom end?

Thanks for any help.

[DanThe]

No, heads are different, bottom ends are mainly the same apart from a few slight differences in pistons and rods throughout the years.
Valve gear is stronger on the Non Vanos, which is the engine I prefer

[Rorty-corty]

OK, ta very much. That knocks that idea on the head then.

I was just looking to see if it were a viable option to try to gain some torque lower down the rev range. Having said that, hopefully the weight-loss program my old E34 has been on will have a similar effect performance wise.

Are these M50 engines happy to be revved? I know there designed for higher revs with being a 24 valve design but it would be nice to know that there aren't any inherent weaknesses that drasticaly reduce engine life the more it's revved. I know that the 2.9ltr 24 valve Cosworth V6 in my Cortina can only take so much abuse due to the open nature of the V6 block. If it where to go racing it would really need a girdle fitting to the block.

Thanks for the help.

[E30BeemerLad]

I believe the non-Vanos lump is much happier having the fanny revved off it and the cams are a little more spikey than in the vanos heads

Edited

[Rorty-corty]

Sounds good, only which way around is it? You've typed non-vanos twice there.

Edited - ta very much, non-vanos is sounding fine as is.

[DanThe]

The Non Vanos cams limit the power delivery to around 7000rpm I found, so if your on a standard chip your nowhere near the limit

[Rorty-corty]

7,000 revs sounds fast enough for me!

Saying that, I haven't started racing yet. I think I'm going to have fun playing with this.

Saying that, it doesn't even run at the moment. I think the AFM is up the spout. I removed the air filter box and has been driving it around work a few times which appears to have upset it. I've heard that the AFM can be a bit sensitive about having it's air feed tampered with.

Thanks for the replies.

[ShakeyC]

Contrary to popular belief the vanos and non-vanos drive pretty much the same the only major difference is the emissions on the vanos engines, torque and power differences are insignificant between single and double vanos and non-vanos.

[Rorty-corty]

Really? I thought the whole reason for developing the Vanos system was to improve the relatively low torque at lower rpm?

[ShakeyC]

nope its purely for emmissions purposes, there is some difference in the graphs but not enough to reflect the actual changes in cam durations a vanos engine has when it kicks in and out. Therefore to say vanos is there to improve low end or mid range torque is wrong as the only notable changes can be seen on a exhaust gas analyser.

[Rorty-corty]

Cool, it's sounding like the non-vanos is the better of the two for track abuse then. That suites me fine. Reliability is an important factor as I haven't the money for constant repairs and rebuilds.

[GeoffBob]

Rorty,

Purely for your interest, you'll find a brief description of BMW's single and double VANOS systems here

For what it is worth, I have always seen VANOS (VVTi and VTEC etc) as a mechanism to make longer duration cams (traditionally for the performance orientated) behave themselves at lower RPM and to facilitate exhaust gas recircultion (with VANOS II) back into the combustion chamber which improves emissions. I am, however, no expert when it comes to VANOS.

I can't help thinking that (unless you are particularly concerened about your carbon footprint) a non-VANOS engine with a decent set of lifting/duaration cams would be the way to go. If I have read the above correctly I understand that you are planning on racing this car?

[Rorty-corty]

Thanks for that, it certainly does seem to be more biased to emissions than torque improvements.

And yes, I am planning on raceing this car, but only on track days (if I can afford them) and the Practical Performance Car magazines £999 challenge.

Cheers for the help.