Valve spring comparison M50 vs. M52 vs. S52

[andrezbim]

UPdated with M50 new spring and M50 non vanos spring set.

[5mall5nail5]

Awesome - so the myth of M50nv springs being stiffer is true

So who wants to put some money together and buy Andrezbim some Supertech springs to compare?

[andrezbim]

Actually... if anyone wants to send me any spring to compare.. scouts honor I"ll return it straight away.

I thought it was interesting that the S52 spring is the same for the S62 [per nr search]. Maybe the other v8 engines might have a spring option?

[techno550]

Awesome - so the myth of M50nv springs being stiffer is true

above or below the 1/2 inch mark?


OP, how about spring rates from installed height to around 0.5 inch of compression?

[SiGmA]

Mike, do you know what installed height is? I do not have any data with me currently, I'd assume installed height is about .4" shorter tho, and then we can add a half inch on and get the relevant spring rate numbers, right? I'm very very curious as to getting accurate results for spring measurements from this thread. I supposed I overlooked the fact that we need uncompressed heights too right?

[andrezbim]

above or below the 1/2 inch mark?


OP, how about spring rates from installed height to around 0.5 inch of compression?

These measurements were all take from 2" above seat.
So if the installed height was, for example, 1.6", then you would look at the deflection at 2"-1.6" = 0.4" deflection .. and that would be the installed spring force [preload]. At 0.5" of compression, the spring would deflect from 0.4" out to 0.9" deflection. It seems the data is already here.??

Mike, do you know what installed height is? I do not have any data with me currently, I'd assume installed height is about .4" shorter tho, and then we can add a half inch on and get the relevant spring rate numbers, right? I'm very very curious as to getting accurate results for spring measurements from this thread. I supposed I overlooked the fact that we need uncompressed heights too right?

I can add the installed height to the graph to help add a visual. The free lengths are all included in orig post.

[andrezbim]

Found a reference of 35.5mm - 36.5mm [depending on seats used] for the installed height. Can someone 2nd this?

I will add a vertical line to show this installed height on the graph as well as a reference 10mm stroke [varies with cam] to show an approximate operating range of loads.

I also found a data sheet that shows supertech springs force per deflection... will add as a reference only [until such time that I can measure one].

[RascalKing]

What would be the difference when changing cams with the springs?
I.e. M52 cams with S52 springs/lifters etc...

[Jason C SBB]

Watch out, BMW mate different thickness seats with different springs. A thicker seat means more pre-load and thus shorter installed height - you need to look at force vs. valve lift for the spring and seat combo.

In addition, a thick seat and the wrong spring will BIND at higher lifts.

Here are some of my findings:
http://forums.bimmerforums.com/forum...php?p=16103532

[someguy2800]

just to dig this thread back up, what do you need to put the NV springs in a vanos head? With they fit the vanos m50 retainer?

[elinn e36]

Bringing up an oldie here, but was looking to put s50 springs in my m50 head because I was planning on doing s50 cams. When comparing part numbers, it looks like these engines have different spring seats and retainers as well as lifters. I want the conical s50 springs for their lightweight, benefits of being conical and lower height for use with s50 cams. Can I just replace the seats, springs and retainers w/ s50 parts on my m50 head or is it more involved? Also, will the m50 cam carriers and lifters work fine with s50 cams?

Thanks,
Eric

[andrezbim]

just to dig this thread back up, what do you need to put the NV springs in a vanos head? With they fit the vanos m50 retainer?

They should fit, but you'll need the spring set up for a nested spring set, ie. the nv spring plates and pockets. The nested spring set needs the pockets to stay centered.

Bringing up an oldie here, but was looking to put s50 springs in my m50 head because I was planning on doing s50 cams. When comparing part numbers, it looks like these engines have different spring seats and retainers as well as lifters. I want the conical s50 springs for their lightweight, benefits of being conical and lower height for use with s50 cams. Can I just replace the seats, springs and retainers w/ s50 parts on my m50 head or is it more involved? Also, will the m50 cam carriers and lifters work fine with s50 cams?

Thanks,
Eric

S50=S52 springs, i think you're on the right track. You're doing a na setup i take it? Seats are different thicknesses as mentioned, and it's difficult to measure the clearance left in the spring after it's all in there so matching seats springs retainers keepers etc is def the way to go... not to say it can't be done other ways. The issue is really available spring strok before it bottoms out on the coils, and since you're matching there's some "mass production" tolerance that's built in. You could probably mix and match as long as you're considering seat thicknesses and cam lift.

Good luck with your setup and let us know how it goes when you're all done.


Oh, yeah the lifters should work.

[328iJunkie]

Any updates on this?

[JUS2K]

I'm in the middle of headgasket job....dropping in S50 cams at same time. Can I re-use lifters? Car has 130K on motor. From this thread I gather I should change springs(was planning it anyway). But, which springs to use? M52 or S50? Changing springs means I should change seats and retainers to match? i.e. S50 springs, seats and retainers. Any helpful advice would be greatly appreciated. Thanks peeps. Peace. PG

[andrezbim]

I'm in the middle of headgasket job....dropping in S50 cams at same time. Can I re-use lifters? Car has 130K on motor. From this thread I gather I should change springs(was planning it anyway). But, which springs to use? M52 or S50? Changing springs means I should change seats and retainers to match? i.e. S50 springs, seats and retainers. Any helpful advice would be greatly appreciated. Thanks peeps. Peace. PG

As a general rule, match cams with springs, so S50 cams -> S50 springs (same as s52). Also, match seats and upper spring plates to springs, this should eliminate any risk of spring bind. I think the valve retainers are all the same.

I just reused my lifters having had the machinist "check" them.

[JUS2K]

Thanks for the helpful info andrezbim....not what I wanted to hear wallet-wise...oh well. Thanks again. Peace. PG

Question on keepers and lifters was due to age/fatigue/mileage.....bigger lift/duration cam won't be too much for 130k keepers?? Just want to do job once only. Thanks. PG

Question on keepers and lifters was due to age/fatigue/mileage.....bigger lift/duration cam won't be too much for 130k keepers?? Just want to do job once only. BTW, I'm running NA, not FI. Thanks. PG

[andrezbim]

Thanks for the helpful info andrezbim....not what I wanted to hear wallet-wise...oh well. Thanks again. Peace. PG

Question on keepers and lifters was due to age/fatigue/mileage.....bigger lift/duration cam won't be too much for 130k keepers?? Just want to do job once only. BTW, I'm running NA, not FI. Thanks. PG

I'm not sure that I'm quailified to make a recommendation considering the mileage. I know there are plenty of vehicles with mileage in excess of 130k. Having said that, I would probably replace keepers anyway. The lifters are YOUR and your machinists call. I would at least clean and compress them all, and replace any that behave differently than the others.

Best of luck.

[GGray]

Omtresting. I have a set of dual euro motor springs laying around my guess is they are even stiffer than the NV springs...

You don't hear of many NV motors overreving and bending valves ...

Th high RPM harmonics issue is with the crank damper. Not the valve springs.

Interesting.... I may use a set in my S50 when I rebuild it with a high lift cam

[Quicksilver328i]

I'm not sure that I'm quailified to make a recommendation considering the mileage. I know there are plenty of vehicles with mileage in excess of 130k. Having said that, I would probably replace keepers anyway. The lifters are YOUR and your machinists call. I would at least clean and compress them all, and replace any that behave differently than the others.

Best of luck.

Do we actually have keepers fail?

[das Boot]

ok, befor i pick up a m50 head from 92 325i will i be bale to swap over my supertec's from the damaged s52 head what should i expect comparing spring seats?

[EMC]

ok, befor i pick up a m50 head from 92 325i will i be bale to swap over my supertec's from the damaged s52 head what should i expect comparing spring seats?

I have both heads sitting here and the spring seat area on the heads look the same. I can't take any measurements because the vanos head is assembled. The non-vanos head was cut into sections on the band saw.

[SiGmA]

ok, befor i pick up a m50 head from 92 325i will i be bale to swap over my supertec's from the damaged s52 head what should i expect comparing spring seats?

I believe you should be able to swap the valves over. You may have to machine out the little head bolt washer retainers tho, both NV heads I have dealt with have washer retainers. Additionally you MUST replace the guides, as they are 7mm vs 6mm, but I believe you were planning on that anyway.

[andrezbim]

ok, before i pick up a m50 head from 92 325i will i be able to swap over my supertec's from the damaged s52 head? what should i expect comparing spring seats?

It'd be quite usefel to this thread if you would take a closeup picture of the supertecs so I can post at the beginning. Thanks in advance.

I have both heads sitting here and the spring seat area on the heads look the same. I can't take any measurements because the vanos head is assembled. The non-vanos head was cut into sections on the band saw.

Would you mind taking a picture also? Thanks for the help.

I believe you should be able to swap the valves over. You may have to machine out the little head bolt washer retainers tho, both NV heads I have dealt with have washer retainers. Additionally you MUST replace the guides, as they are 7mm vs 6mm, but I believe you were planning on that anyway.

I think he means the springs?

[George318]

It would be nice if you could make a set out of the M50 vanos and the small m50 NV spring and compare it with the stock M50 NV one.The Vanos with NV small one sould be the winner and probably a good upgrade for aggressive cams and higher RPM.

[andrezbim]

It would be nice if you could make a set out of the M50 vanos and the small m50 NV spring and compare it with the stock M50 NV one.The Vanos with NV small one sould be the winner and probably a good upgrade for aggressive cams and higher RPM.

Funny...I thought the same thing. But I think when I tried that they didn't fit together. It's been awhile though, I can't remember. I still have the nv spring set around though, and if I find the old m50 springs I'll try again. Seems a bit risky anyway, if there's not sufficient clearance between them or too much for that matter; you'll risk binding them together or wearing them out. I've seen that happen when doing torque converter clutch designs with nested springs.