Info Request: stiffer valve springs

[NoSoup4U]

Does anyone know where I can get stiffer valve springs from? I DO NOT want the titanium valve springs. I believe BMW uses stock single springs, I was hoping for double valve springs or, at least, stiffer than the stock single springs.

Thanks

p.s. -- I know about BMP's but you need to purchase the titanium retainers -- which they are out of stock and no clue when they will come in ...

DAMN -- I AM SOL on a lot of things ...

What the heck is wrong with BMP --- everything I've wanted, they've been out of stock ..

all hg's = out of stock
retainers = out of stock
single spring valve stiff = out of stock

etc...etc..

GRRRRR...

[aceves]

Here you go:
http://vacmotorsports.com/cgi-bin/vi...m.pl?item_id=7

[badmonkey]

Why do you think you want stiffer valve springs?

[NoSoup4U]

Thanks aceves -- I only saw their complete package for $1K.

I would prefer not to use titanium retainers though.

Badmonkey -

a) stiffer valve springs allows me to move my rev limit up to 8K comfortably, I could probably go as high as 9K if I really wanted to. The dual valve springs allows the engine to rev up to 12K rpm's :eek ... plus if one spring fails, the other one is there still. This would also help with mis-shifts/money shifts as well. I have been fortunate; but, if I can prevent it with some added insurance -- why not!

b) All valve springs will experience/or inherently experience valve float according to James Clay, VAC, BMP, AA, Turner, etc. ESPECIALLY if you auto-x, getting on and off the accelerator -- I highly doubt that the valve springs all have the same tension after a while. I have around 50K on my engine now.

I am pulling off my head -- redoing the headgasket and some minor work to it. Nothing really crazy -- but, if I can move my rev limit up to 8000 or 8500 (haven't decided which) ... then that would be invaluable in auto-x ... plus, it allows me to hold boost THAT MUCH longer -- which in effect -- makes me go faster I would like to pnp the head a little, and do a 3 angle radius cut to it. 5 angle might be a little to aggressive for my tastes.


If I am wrong, people correct me please ... I'd love to save some money!

[John in Houston]

Hey Soup.... did you ask about the lifters? I know on Mustangs (yeah, back to that again)... you could put heavy ass springs on the valves, but then you ran the risk of lifter collapse as the hydraulic lifters couldn't keep up with the spring rates. So you still had issues.

Why don't you want to go with the Ti Retainers? Just an FYI, the cause of my motor's demise at the SCCA Nationals in September was a broken retainer. This is on a 98 M3 which had the upgraded retainers.... pretty rare that this happens. The car only had 50k miles on it. Also, some springs won't work with the factory retainers and locks.

Another thing..... if you have a spring out, you can take it to a reputable machine shop and have them check it out. They can find the free length, diameter, thickness and rates and then look it up in their parts catalog. You can probably save a couple hundred $$s buying from them vs. one of these BMW speed shops with high mark-ups. That's what I'm planning on doing as I rebuild the old motor for Street Mod duty. This is also what I did on my Street Mod mustang.

Anyway, that's my thoughts... just some stuff to mull over.

[badmonkey]

Originally posted by NoSoup4U


If I am wrong, people correct me please ... I'd love to save some money!

Let me rephrase, why do you think you need stiffer valve springs.

Isn't your car turbo?

No need to be revving to 9k. Maybe for the racer yes. Is this for a race car?

[NoSoup4U]

Badmonkey - well, wouldn't revving up to 8500 rpm's in essence mimic a taller rear end for me? I could hold boost longer?

The springs at VAC can go up to 12K rpms ...

This would be invaluable in auto-x, wouldn't it? This would be invaluable period -- making my first gear much more useable than it is now with a 3.23 stock rear. I would set my rev limit to 8200-8500 then.

If you guys want, follow along in this thread of information I was told and found out ...

http://www.bimmerforums.com/forum/sh...hreadid=146095

Kind of like a diary as I work through my engine.

John -

Well, they DO recommend using titanium retainers -- BMP, AA, VAC, etc. The problem I am running into is, many of the f/i people and others I speak with recommend NOT to use titanium retainers. That this part is strictly a race type of part that I will end up replacing in a year or two.

However, I have not found a stiffer spring that will mate with the stock retainer. It does not have to be a double spring ... but, most single stiffer springs require the titanium retainer, or so I am told.

Hmm... thanks for the tip, I'll pass that along. I was going to chech the spring rates to see if any of them are out of whack and that was going to primarily determine if I replace them. I may end up going with stock springs again, if the price is significantly cheaper than $1K.

What type of upgraded retainers are there for our cars? BMP sells the titanium retainers for $374.95, VAC sells them with the dual valve springs, AA sells them with the dual valve springs. However, BMP is out of stock. VAC only has the dual valve spring kit ... for $1K with titanium retainers.

The single valve springs cannot fit stock retainers on the BMW according to BMP ... so, titanium retainers are needed ... but, as mentioned, I'm running into people saying, do not put it on a daily driven car.

What do you suggest?

First, no, I do not need to have a higher rev limit. The main purpose of contemplating stiffer springs is because of valve float. People were recommending that since I am f/i AND I auto-x and track, that stiffer springs are highly recommended. People said that ALL BMW springs will experience some valve float ...

But, I run into the problem of titanium retainers though that some say never use unless I want to rebuild my head every year.

Second, I could go with new stock springs and retainers ... but, that seems a waste of money if I can go with something that is better for a little more money. Not sure how much 24 springs from BMW cost; but, I'm sure it's not cheap. Not sure how much retainers are as well.

The engine has 50K on it ...

Third, my head is coming off no matter what .. and no matter what, I have to have it resurfaced ... when you add stiffer springs/retainers, I was told you need to get it milled a little for it to fit properly ... so, I figured if I need headwork done -- why not do this mod.

Should I avoid it?

[fast4d]

another thing to ponder:

will you intake manifold sign off before the rev limit?

stock redline is 6500/6700?

[NoSoup4U]

alright -- well, scrap the idea of a higher rev limit ...

What about stiffer springs/titanium valves with stock rev limit of 7200 rpm's ?

Good or bad?

[John in Houston]

Soup -

I'm not sure what your setup is... but if you are running stock cams, then stock spring rates should be fine.

Are you currently experiencing float? You should be able to pick this up in the graph of a chassis dyno in the upper RPM range.

Going to a heavier spring with heavy-duty retainers would alleviate any valve-float.... but are they necessary if you don't already have float?

If you are getting your head P&P'd, then have the machine shop check your springs (all of them) and see how they compare against stock spring rates. If they are weak, then replace them.

Personally, I have not experienced valve float on the M3.... no signs of it on the dyno either.

On the topic of being able to run higher into the rev range, there is no need to do that if you aren't making any additional power.

What did your dyno graph show?
Was the power leveling off at your rev-limiter?
Was it already dropping?

If so, then being able to rev higher really does nothing for you. If you were still making power when you hit the limiter <or> you experienced valve float at the upper RPM limit which was costing you power, then I'd say go for it.

[aceves]

What's wrong with revving to 8K that's like asking why do you want more HP.

[John in Houston]

Originally posted by aceves
What's wrong with revving to 8K that's like asking why do you want more HP.

Maybe I'm missing something in your brief post.... but what do you think you get by revving higher? More HP? More speed?

Not necessarily. As posted above, if your dyno graph already shows HP dropping off at the rev-limiter, then why would you rev higher? There is no gain to be had.

Case in point: Before we installed my 347 in the mustang, we strapped the car down to the dyno with the original 302 engine in it. We ran the car (4t gear) until it would go no more. At 5500 rpm it peaked at 220 rwhp. At 7000 rpm, it was making 24 rwhp and 18 ftlbs. With this being the case, should I keep revving my car? No.

[Def]

a) stiffer valve springs allows me to move my rev limit up to 8K comfortably, I could probably go as high as 9K if I really wanted to. The dual valve springs allows the engine to rev up to 12K rpm's :eek ... plus if one spring fails, the other one is there still. This would also help with mis-shifts/money shifts as well. I have been fortunate; but, if I can prevent it with some added insurance -- why not!

b) All valve springs will experience/or inherently experience valve float according to James Clay, VAC, BMP, AA, Turner, etc. ESPECIALLY if you auto-x, getting on and off the accelerator -- I highly doubt that the valve springs all have the same tension after a while. I have around 50K on my engine now.

Both of these are false.

You absolutely cannot rev out hydraulic lifter heads up to 8k RPM reliably. The lifters just can't keep up. Going to solid lifters would allow you to probably rev this high, as I think the bottom end could take it. No guarantees you won't be rebuilding every 30-50k miles under boost with piston speeds that high though. Although our motors do seem ridiculously stout on the bottom end...

As for experiencing valve float when getting off the throttle? That's just ridiculous. A cam follower system doesn't necessarily care what the angular acceleration of the system is(within reason of course), but the angular velocity is the determining factor of performance. So that means that you can get off the throttle all you want, but as long as you are below their maximum safe RPM limit, you are golden as far as valve float.

Besides, if you routinely float valves, your valvetrain wouldn't last more than a few hours before every component would trash itself. For the rocker arms to come crashing down onto the cam everytime you got up high in the RPMs, they would kill themselves in short order.

As for more revs, I hope your head flows REALLY well, as it is already underflowed a bit from the factory(same ports/valve sizes as the original M50B25). Otherwise you better have one huge honkin' turbo to still make power up that high, and even then you are beating your head up against a wall(rapidly dropping volumetric efficiency up that high), so make sure the whole package can handle it before you go searching for the magic RPM number.


The simple fact is, these motors just cannot affordably rev up that high. If you want more revs, swap in a Euro S50B32 and then work on that sucker.


Oh yea, stay away from Titanium for a street motor(sees you know this). It is actually a very soft metal, and steel springs will gall it to nothingness in as little as 15-20k street miles. Ti only makes sense when you don't need longetivity but that extra few grams on the retainer will allow you to get by with a lower spring seat pressure to run the revs you need(i.e. more power through less loss in a race environment). I know all about Nitride and various other coatings, but I still say Ti retainers are just a bling-bling "OMG I got Ti retainers, this motor is beast!" bragging item for a street driven car.

[E30 Stu]

As for the 8K+ redline, Def pretty much answered that. The factory 35mm (or 33) hydraulics can't keep up with that kind of engine speed. You need solid lifters to BACKHAND 'em.


We use M3 conical valve springs and 3.2 retainers on almost of our built M50/S50 street motors. They work fine with stock M3 cams or fairly mild Schricks. There have been a couple cases where the conical springs were maxed out with Schrick race cams, and in that case, we use non-VANOS M50 double valve springs.

Conical valve springs are good for about 7500rpm. The M50 cars in my family have 7300-7400 rev limits, however my friend Max turns his 2.5 (M3 cams) 7500 with no problems so far. 7500 isn't necessary, just so you know. 7400 is only needed on the 1-2 shift because of the E36 gearbox's long ratio on that gear change. (assuming M3 camshafts).

[Alex McHenry]

Anyone wanting to turn over 7500 is just a show-off.. There are few cams out there that even produce power in that range, and the ones that are available are Solid Lifter setups, not hyraulic.

Only a small displacement 6 will benefit from that kind of revs (2.0 - 2.7 liter)..

[badmonkey]

Soup

If you are looking for power, I'd get either some custom tuning done for your turbo or go with a standalone, and optimize components. IMHO, AA leaves a lot of power on the table, probably in favor of reliability.