Looking for M30 Valve Spring Specifications

[Shawn D.]

Y'all,

What are the specifications for M30 valve springs? Specifically, I mean:

- seat pressure (zero lift)

- open pressure (at "X" lift)

- coil bind (how much valve lift before the coils touch each other)

- ID and OD (ok, I can measure this when I get home...)

TIA,
Shawn

[Devinder]

took me a while to find this in my stuff:

MM in their brochures lists stock M30 springs as 240 lb/in and 70 lb seat load.

I measured a spring from my E9 a few years ago and got 217 lb/in spring rate, 73 lb seat load, and 159 lb at 10 mm lift. I measured the spring dimensions too:

total no. of coils 6.0
no. dead coils (at load) 2.0
wire diameter 4.25 [mm]
coil od 31.90 [mm]

Let me know what numbers you get.

[Shawn D.]

Devinder,

Thanks for spying this thread and especially for having done useful measurements!

I don't have a spring checker, so I won't be able to give you any data other than the dimensions. Now if I could just find the springs and a caliper to measure them...

Thanks again,
Shawn

[Devinder]

Shawn,

The other place to look is in the Schirck catalog. I know they have all these numbers for replacement springs. Their catalog is on their website somewhere.

Devinder

[szacsi72]

took me a while to find this in my stuff:

MM in their brochures lists stock M30 springs as 240 lb/in and 70 lb seat load.

I measured a spring from my E9 a few years ago and got 217 lb/in spring rate, 73 lb seat load, and 159 lb at 10 mm lift. I measured the spring dimensions too:

total no. of coils 6.0
no. dead coils (at load) 2.0
wire diameter 4.25 [mm]
coil od 31.90 [mm]

Let me know what numbers you get.

Have to wake up this thread after many years.
I suppose this is the single spring version.

Does anyone have the specs for the B35 double spring? I need to know in order to decide on what springs to run. I need 35kg installed pressure for my cam.

Thanks
Dave

[szacsi72]

I measured my original B35 springs and used this calculator: 
https://www.thespringstore.com/spring-r ... lator.html

And got the following results.
Installed seat pressure main 272N, helper 51,27N --> 323N ~ 33kg ~72,7lb
Spring rate main 24,737N/mm helper 9,323N/mm --> 34,06N/mm ~3,5kg/mm ~195lb/in

Which means @10mm lift
663N ~67.5kg 148.8lb


Does anyone use these PPF springs?
https://pure-pf.com/product/m30-valve-s ... t-stage-1/

[Shawn D.]

Thanks for updating the info!

[szacsi72]

Here's some more accurate updates, comparing 30-35yr old B35 springs and brand new OEM springs!

[Shawn D.]

Great stuff!