Vanos to Non Vanos
Hey Guys , so ive been searching like crazy on various different Bmw forums :dunno !! and hoped that you boys can enlighten me with sum knowledge .....:drummer
so the thread starts like this :
Parts i have currently
M52 single vanos motor complete
M50 non vanos head complete
M50 non vanos pistons
Objective :To eliminate the vanos so i can run full AFM on the engine. (dnt wana tune the vanos or have to service it )
so ive found out that a M50 NV head will work on a M52 Single vanos bottom end, BUT :ranting ..... what i have gathered is the the M50 NV cams are more aggressive than the M52 cams , hence it will cause "Valve interference" and the compression will be too high !!!
so i wanted to know if i can use the M50 NV head and piston on the M52 block
Put the M50 NV intake cam/trays/lifters/springs in with the M52 exhaust cam ( It performs better than the M50 NV exhaust cam )
into the M52 block using M50 NV pistons to get compression correct
Please feel free to scrutinize any of the info if its incorrect !!!!
M52 has no vanos
M52TU has single cam vanos
Which variant are you referring to?
Every BMW engine is an interference motor, that's why the timing needs to be correct so I don't understand valve interference question.
Compression ration has to do with the distance the piston travels inside the cylinder (stroke), cylinder diameter and combustion chamber volume. The valves don't enter into the basic equation. Changing the timing, lift and/or flow rate of the valves can, what are you using to do your math with?
So even if the cams are more agressive , if the timing is correct the valves wont hit the pistons right , cus the intake cams lift on the M50 NV is 9,7mm and on the M52 its 9,0 mm ......
as for the compression the M50 NV pistons are not the same height as the M52 ......
and i read that the valves on the M50 NV head stick out about 1mm causing the compression to be higher than normal .....
M52 no vanos
M52TU single vanos (that was the TU) according to BMW themselves (factory literature) when I went there for tech school. I'm looking at an M52TU in my E34 as I type and it is single vanos. Double vanos happened on the M54 engine which was made up until a few years ago. All good engines.
Regardless it doesn't change the question
.7mm isn't terribly significant but it will improve flow through the engine which is what you're after as more air and fuel with more compression equals bigger bang and more power. Taller pistons with more valve lift COULD be an issue but shouldn't cause much concern as long as you get the tolerances and timing correct.
Have you built engines before? You need to know the deck clearance of the pistons with the connecting rods and bearings you want to use. The thickness of the head gasket you're planning to use. Do some addition and subtraction to see how the will jive with your valve lift. It's not difficult but it MUST be correct or you'll destroy all you hard work the first time you crank it over.
Just out of curiosity, with all the engine bit questions. Why not just source an engine out of an M car someone has rolled or something? Or, I'd be on the lookout for an N54, that's the latest greatest inline 6 with the twin turbo set up. It'll destroy just about anything else on the road. And in an E30...............THAT would be freakin awesome.
so normally to stroke a M50 NV engine from 2.5 - 2.8 , they use a M52 crank/rods but M50NV pistons ...... so my reasons for putting the head and pistons on is jus to maintain that same standard compression with alittle better lift on the intake valve. so what u say u think its can work ....?
1more question when installing perfomance cams what should one take into concideration ....:dunno
You should be able to compensate with a thicker head gasket, but it may be easier to go with the shorter pistons because raising the head moves the combustion chamber up and lowers the compression ratio back down (more or less a zero sum gain). Slightly longer stroke but that's not necessarily going to return much for potential headache. BMW engineers these things to give as much as possible, it gets very tricky and expensive to get more. You might be better off sticking to OEM specs and adding a turbo or supercharger. Just depends on how much time you want to spend, 100's of hours trying to make a better NA motor, or 20-30 to add some external compression to the engine. In the end, what's your time worth?
Cams and heads, port and polish, more lift on the valves, and at least a three angle valve job. More flow=More power. You can get gains by a simple head job and leave the bottom end completely untouched. But again, bear in mind BMW designs these things to be as good as they can be while at the same time running reliably for 100's of thousands of miles. If it was Chevy 350 there are TONS of things you can do (engine was designed like crap from the word go). Most German engines, not so much. They're pretty well built from the beginning.
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