Try they are the same part number... I went through this five years ago working on adual spring conversion for my S52...
Make sure you let BMW know they are wrong
You do realize like all major manufacturers they source things from multiple suppliers they may be slightly diffrent heights when not under compression but they are the same springs. BMW lists one part number for them..
Gary Gray
If you can take it apart you can make it faster!
Thanks,
All the information for spring rates were averages take from multiple springs. They are not variation from spring to spring.
The heights were also ALL taken from averages.
To repeat the information AGAIN:
The M50 spring part # is 11341738488
http://realoem.com/bmw/showparts.do?...87&hg=11&fg=25
S52 Spring Part # 11341403709
http://realoem.com/bmw/showparts.do?...87&hg=11&fg=25
M52 spring # is 11347504268
http://realoem.com/bmw/showparts.do?...87&hg=11&fg=25
This is information FROM BMW.
Also, you can clearly see from the picture that a M50 spring is NOT conical.
All of these part #'s were ordered and verified through BMW and taken from BMW stock inventory.
Last edited by andrezbim; 08-19-2011 at 11:43 AM.
Andrezbim
What i meant that is i could rev (if i wanted) til 7800rpm, not that i am doing that always, but thanks for your advice. My M3 OBDI came with a 2.5 bottom end, and with the NV head, with vanos adapted, but i stroked to 3.2L with forged internals . That is why i am using the double springs and bigger lifters.
So with that said, using bigger cams ( sunbelt sports, vac or evomotorsport)profile with these same springs will afect my performance? or it will help me to over rev? what cams would be the best for drag race?
Thanks
Last edited by cetrero23; 08-25-2011 at 12:30 PM.
so what is a safe rpm without compromising?
if i change cams, like sunbelt or vac what will be the safe rpm?
2010 - BMW 335i M-Sport - Lemans Blue Metallic
BMW PPK2, JB4 with NLS, Backend Flash, BMW PP Exhaust, Misc Appearance Mods, Boost Addictions Diff Brace, BMS DCIs, BMS Clutch Stop, VRSF Catless DPs
Previous:
1995 M3
1998 323is
Anyone doing research on the nv dual spring set retainers for 6mm valve stem the only one I found would be the euro s50 b32 they would have to be ordered from the motherland germany and I didnt want to wait to see if they would work but might be an option.
Jimmie
Yes. I want to fit 6mm valves m52 with m50nv double springs and s50b32 euro retainer. But my friends told me that if you increase spring pressure + bigger cams it might be too much and the cap off the valve could blow. And m52 6mm valves has 1 lip where the keepers go. So dont know what to choose. Dont want to add 7mm valves nv springs because then i must use 35mm tappets and different cam lobe. Because m52 wont fit 35mm tappets, correct?
I don't know of any issue with running 33mm m52 tappets with non vanos valves and retainers. I just looked at a set in my garage and the retainers fit inside the lifters. You can also run 35mm tappets in an M52 head, you just need to get the tappet trays out of an m50 as well. You can also use any cam with any tappet that you want. I have never seen anybody have problems with stock M52 valves, springs, and lifters up to 7400 rpms so unless you are reving to 8000 rpms you really don't need any upgrade. If you want to upgrade from single springs I would just get a complete non vanos head.
So it is safe to drift without any changes to my valve train unless cleaning? I want to regrind my cam but dont know how much lift a stock m52 spring will have.
In my case what would be better
s52
06 SPRING POCKET 11341403612
07 VALVE SPRING 11341403709
m52
06 SPRING POCKET 11341735254
07 VALVE SPRING 11347504268
Or 6mm valves m50nv double springs and evo retainer?
Car is for drift. Im not going over 7200 rpm but i would like to rev from 3 to 7 a lot.
Old but Gold thread ...
M50 non vanos valve springs vs s52 valve springs ...
that what i say can 280/272 cams work with s52 valve springs better than the non vanos m50 springs thats my opinion.
with lighter pistons and con rods 7600 max rpm with schrick lifter
you compare 68g to 37g valve springs you compare 33mm lifters 49g to 35mm lifters 70g.
6mm 47g valve to 7mm valve 60g ....
yes its a stronger spring but no perfect bulid for the s52 setup
if any want to drive more aggressive cam yes i understand the stronger valvesprings but no m50nv....
drive m50b20 non vanos and drive m52b20 !! the differnce its a lot !!!!
Last edited by HaliliM3; 04-30-2019 at 07:18 PM.
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