Do not bother with JEGS. The only reason they don't show these springs as not available is for you to try and order them, and fill your basket with more of their shit. I contacted them multiple times, concluding they don't know, and the manufacturer does not have an ETA. All info I got was that JEGS is waiting for a huge order for this part.

First ordered them on March 10. Well it's been 05/06 and guess what? Nothing yet. They offered me to cancel the 855s and ship the rest of the order...

https://cimg3.ibsrv.net/gimg/www.mia...82d14c60fc.jpg


About those 418737. Do you have any more info on them? Do you have any info on what they are like yet? :p I also think the ST heavy doubles are a little expensive. Especially to get them shipped to me (Europe). Those 418737 seem to be a lot easier to find around here. Let us know if anyone has more info on those!

That is OEM volvo part numbers for the springs. Swedish parts for swedish bricks. OEM or they might be IPD sourced by now.

VP auto helped me with parts on my old 740 volvo chumpcar. and was the first place i went to get volvo springs and parts.
Volvo posted below.. note the cage.. behind it is a Turbocharge 5 speed plymouth voyager minivan.
https://cimg6.ibsrv.net/gimg/www.mia...729b0c8d0f.jpg

masterjr33, that made me have a flashback to the days of Turbo Minivan of 89 turbo mini van!

The website is still up!

If anyone would like to let me borrow their springs over a week i can run them on my instron tensile tester at work and we can see the exact forces from free length to bind.

I want to get a hold of the , 94-97 NA8, BC spring. Oem VVT, VS855, and the 418737 volvo spring.

Ian I could most likely share an 01-05 VVT Intake and Exhaust spring to help gather data. What do you think turnaround time would be as I would need them back :)

I shouldnt have said i need VVT springs. Got a full 50k mile head set that im looking to upgrade.

Still need samples of the other springs and i really dont want to take data on sample sets of 1.

Ordered Qty 1 of a new Mazda OEM 1996 Valve spring (same part # for intake and exhaust) and Qty 1 NB2 VVT engine's exhaust valve springs.

If anyone has a spare volvoish spring or BC spring i'll gladly measure those too and post results here.

Awesome stuff. The data should be very fun to compare.

Okay so far I have the following springs enroue:

NA8 OEM Valve Spring (PN BP05-12-125)
NB2 OEM Exhaust Valve Spring (BP2Y-12-125A)
Sealed Power NA8 Spring (PN VS-949)
Brian Crower (BC1600-1)

I'm putting together a spreadsheet with all the listed spring variable and trying to fill in the blanks by calculating missing info.

What really gets me is I can't find any info on the NB2 valve springs or installed heights but i'll measure the best i can.

I have some data on those which I provided to BC.

From an earlier post of mine in this thread:

Data Overload!
 

Okay so for the data nerds out there.

I got the chance to test 5 different springs some have mentioned here and in the BP valve spring info thread started by BogusSVO.

All spring unloaded dimensions were measured with Calibrated Mitutoyo calibers and micrometers, force testing was conducted on a Instron Tensile tester using a 250 lbsf max load cell and loaded at a rate of 30 lbsf/min.

1) 50k mile old JDM BP6D Intake Spring
2) Sealed Power PN # VS-949 (OEM Equilvialant for 1994-1997 NA8 engine)
3) New OEM PN# BP05-12-12 Spring (Mazda OEM Valve Spring for 1994-1997 NA8 engine)
4) New OEM PN# BP2Y-12-125A Spring (Mazda OEM Valve Spring for 2001 BP6D Exhaust Valve)
5) New Brian Crower PN# BC1600-1 (Some have suggested this valve as a possibility but measurements show it would be inferior to the oem NA8 Spring)

Hopefully my excel sheet sharing through dropbox works. WARNING: This is a big excel file as I have over 20,000 data points for each spring during the tensile tests.

https://www.dropbox.com/s/p4ovihvg5a...Rev2.xlsx?dl=0

https://cimg5.ibsrv.net/gimg/www.mia...d9a8b87629.jpg
https://cimg6.ibsrv.net/gimg/www.mia...4c8c7e5d1d.jpg
https://cimg1.ibsrv.net/gimg/www.mia...c4749d309b.jpg
https://cimg2.ibsrv.net/gimg/www.mia...e998fb4cd8.jpg

I measured only 1 intake valve position but I did it using a 1.250" long 1" OD .75" ID alum sleeve and a light helper spring from Ace HW. I assembled the valve into head with sleeve and spring in place of normal valve spring. I then used a Brown and Sharp Dial indicator to measure the amount the valve could be pushed down to the aluminum sleeve.

This distance + the 1.2500" aluminmum sleeve (measured with micrometers) equaled a spring closed height of 1.520"

Wait, so OEM NA8 springs are within a few lb of brand spanking new VS855 springs? So everyone that's been chasing those down should have just been looking for new NA8 springs instead?

Wignman703: The VS-949 spring is within a few pounds of the the OEM NA8 spring. I did not have a VS-855 to measure.

But If you go by the golden rule of .060" margin between open compression length and bind (this helps dampen resonant oscillation in the spring) then the OEM NA8 spring is ideal with the measured installed spring height I measured and the VS-855 would be too close to bind. If measured install height we're the assumed 1.555" then the VS-949 would be a good option with a little shimming as it is just a little stronger spring rate.

NA8 springs give me right at .059" bind margin and a good 60.8 lbsf closed (this is for a Naturally Aspirated AutoX engine) while upping full open force by 32 lbsf (162 vs 130, NA8 spring vs NB2 Intake spring respectively) to fight valve float on the steep BP6D intake cam ramp.

Updated the spreadsheet a little with conditional formatting on the coil-bind clearance, with .050" to .060" being ideal.

Damn dude this is amazing info

You're doing the Lord's work here!

I have a set of VS855’s I was going to use on a head build this summer. I could send you a few to test if you want; PM me the info.

PM sent

So I got my 20 BP05-12-125 springs in and primed an excel sheet for more tensile tester data. Tomorrow night I should have it updated with all 21 springs worth of info.

The OEM springs are ground to a surprisingly consistent length of 1.8355 ± .002 (except for one flyer at 1.831).

https://www.dropbox.com/s/g0bknwzjcm...ents.xlsx?dl=0

Alrighty So linked excel sheet above for the BP05-12-125 springs is filled out. Had some interestingly varying bind heights.

Luckily I was able to select from the 21 springs a good set for the intake and exhaust that will be right in the sweet spot of coil-bind clearance and pretty close to each other statistically.

25mB excel file woooooh!

Putting in Work Ian. This is great stuff!

Curious to see what we learn about the VS855 once you test since they're all over the place. And to think that I tossed out a set of NA8 Valve springs...

Darn, it looks like this comes about just as I'm getting ready to build my motor.

I found this spring on Summit, not sure if it helps

https://www.summitracing.com/parts/slp-vs-651/

Edit: after further research it seems the seat pressure of this spring is less than that of stock

I just ordered a set of springs from them. I am heading over Friday morning to meet the guys at their shop and pick up the order.

What do you guys think about the options from Brian Crower?

I bought 16 of them last week from this eBay page:

https://www.ebay.com/itm/Valve-sprin...1a35%7Ciid%3A1

When I messaged the seller to make sure he had them in stock he told me has 100+ of them. This was the only place I could find them as of 7/5/19, free 2-day shipping to 48 states.

Brian Crower sells quality components. I have his forged rods in my motor. Haven't tried his springs yet.

https://www.dropbox.com/s/p4ovihvg5a...Rev2.xlsx?dl=0

Big shout out to Schroedinger for sending Qty 6. of his uber rare VS-855 springs.

Got the average of the 6 units added to my Rev 2 spread sheet. By far the strongest of all the springs.

That’s great. I halfway expected them to be the same as the OE NA8 springs.

So no concerns about coil bind height either?

Not on a stock VVT intake cam with 9.4mm lift. Not the ideal 0.065-0.070" bind clearance to minimize spring harmonics but on par with the OEM VVT Exhaust spring clearance.

I wonder how the light doubles and heavy doubles compare.

Would it be a reasonable idea to use the stronger spring on the intake and the factory spring on the exhaust?

We aren't trying to seal against incoming boost pressure on the exhaust side, and the internal pressure will work to seal the exhaust valves on compression and ignition strokes.

Perhaps the extra stresses aren't worth worrying about, but there's a reason Mazda saw fit to do so on the VVT head.



Thank you for all this work @ian99rt , it fills in a lot of blanks in my limited knowledge.

.....

I can't speak for everyone, but I see valve springs more as precautionary over rev protection then bleeding edge performance.

There's an increased pressure on the exhaust side on a turbo car as well. For my Rotrex build though, I will be doing something similar; using the OEM VVT intake springs on the exhaust, while using Volvo ones on the intake, in an attempt to not increase parasitic losses if there's no need to (most probably by a negligible amount, but makes me feel better)

Valve spring pressure will not contribute to "parasitic loss" in a way which will cost you power. Equal and opposite reactions are taking place. For every valve working against spring pressure to open, one is working with spring pressure to close. Furthermore I have NEVER seen an engine (bossted or NA) make less power with stiffer springs(sure it would happen at ridiculous seat pressure...but in 20+ years of experience, I've never seen it happen), quite the opposite has happened. Controlling valve movement is paramount to making valves live, guides live and making the most power you can. As long as your lifter surface area, valve keepers and retainers can withstand the pressure (and ours can hold well over 100lbs of seat pressure and more than 300 over the nose) there is absolutely no downside (other than cost) to running the stiffest springs you can afford.

Springs are also a wear item. Like any other spring, they will lose pressure with use and the alloy used in the cheap Volvo springs will lose pressure at a more rapid rate than even the stock Miata parts.

I ran these springs for half a season in a Autocross motor, killed a set of valves and tested about 15% lower on the seat when they were puled out of the motor.

With Valve springs being such a highly important component for reliability and power, I would be using the absolute highest quality and highest pressure springs I could afford.

necro bumppp

Thanks for all the info and research @ian99rt. Would be interesting to see the products supertech makes on the bench too. (There is another thread floating around measuring ST singles and heavy doubles, but different equipment and measuring method)

After reading all the research, it seems that a potential combo for a BP6D head with stock cams would to the keep the .020 shims and simply swap the springs out to NA8 valve springs. Coil bind clearance is acceptable, and you simply just get better seat and open pressures. (~25%)

Has anyone tried this? I don't see why it wouldn't work though after reading spring spec sheets.

This could work for many people who are running lower boost or just want some over rev protection with their NA motor. Yes corner/cost cutting and valvetrain should never go together, but let people make that decision on their own with some good info. ;)

I'm running NA8 springs in my VVT bottom end/BP4W head N/A build with stock MSM cams.
I have my redline set to 7400 with the knowledge that a bad enough misshift at redline is probably going to mess some stuff up.

Also here is that other thread I found with some good data: https://www.miataturbo.net/engine-performance-56/mazda-bp-valve-spring-info-70450

Neat. Did you decide to do that due to the data in this thread?

In all my research and calculations, it really seems to be a good bang for the buck if you're not looking to rev out much, and it's been sitting in front of us for a while. That's assuming that I'm not totally missing something...which is very possible.

With the supertech stuff, if you look at their specs they really don't make sense. Their claimed spring rate for each offering doesn't line up with the other specs they list (seat pressure and open pressure) and what people have measured themselves. If you calculate it out (assuming the force is totally linear, but that assumption is close enough for most things). So who truly knows what is right besides the pros who simply found out when they float/bust stuff.

The VS-949 ones from rock auto are out of the question due to the coil bind clearance being too close for our cam. VS-855 is unicorn dust now. (Found out today the manufacturer is not making them at all as previously mentioned)

It's just the choice now of ST singles or go with the OEM NA8 valve springs for a stock redline/7400 RPM build with a BP6D intake cam. Obviously the NA8 springs work, but do yall think they really are helping much? On paper they seem like they would, and be a worthy upgrade/money shift protection if you're not going all out with ST.

Yes. I needed 2-300 extra RPM to avoid bouncing off the limiter for 3 seconds, or doing a split second awkward 3-4, 4-2 shift at a local track.
Saving $300 on valve springs that I wouldn't be able to take full advantage of allowed me to put that money to a damper, which will be protection through my entire rev range.

That’s exactly my thought process as well. Save a bit here (yes cheaping out in a valve train isn’t the best idea...but this is calculated!) and throw it towards a fluidampr. That seems to be the better one between ati and them. Less harmonics and safer for the pump.

Anyone running the VS855 springs in an MSM head? Any issues with fitment?

Not to bring back a thread from the dead, but I ended up buying the VS437 / 418737 springs from ITM engine components. These springs seem to be pretty readily available for the time being.
Ebay Listing I bought from: https://www.ebay.com/itm/Volvo-122-1...kAAOSwpuBZ2Wkf

They installed just fine and everything fits up good. Quite obviously stiffer than stock. My feeling is these are the same as the VS855 based on fitments listed for them. If the specs listed here for the VS855 springs are accurate I can take measurements and compare to this page here: https://www.thewrenchmonkey.com/prod...d-power/vs855/

Good news for some of you is that I'm a dumbass and lost two so I had to order an extra set and now have some extras if anyone wants them for testing with just let me know.

Did anyone get data on these?

https://www.psisprings.com/

This is the company that developed the springs for NASCAR which allowed their motors to turn over 9000+ rpm. They make their own springs in house. Someone more knowledgeable than me should approach them about making a spring(s) for our applications.

https://www.popularmechanics.com/car...ascar-6643778/

(This is the article that got me thinking about this)

I'm going to bump a 9 month old thread and say thank you to all of those that led me to VP autoparts... I'll be using them in a stocking VVT NA build unless someone has a compelling reason I should not.

https://vp-autoparts.com/en/artiklar...20-b30e-f.html