New 2056 with big valve 2.0 heads in progress!, I have done various searches and have not found good info on this subj Options

[gothspeed]

Thus far I have decided on:

2056cc with around 8.5 compression

44mm intake and 38mm exhaust valves on lightly ported 2.0 heads (in progress)

44mm IDF webers or 40mm depending on more feedback (though leaning 44s).

Custom exhaust with 1.625" primary tubes.

I want to be able to rev to 6k maybe 6.5k max RPM

I have tentatively decided on the Web Cam 494 grind camshaft with specs below:

--------------------------------------------------------------------------------
Web Cam
Part #: 00-682
Grind: 494

--------------------------------------------------------------------------------


----------------------------Intake ----- Exhaust
Valve Lash (Inch):-------.006 ------ .006
Valve Lift (Inch):---------0.465 ------0.465
Valve Lift (mm): ---------11.81 ------ 11.81
Advertised Duration:-----280° --------280°
Duration @ 0.050":........244° ---------244°
Lobe Center:.................108° ---------108°

So now the question:

Using 44mm and 38mm valves, standard 1.3 ratio rockers with a 494 cam, what is the RPM limit using standard 'single' HD springs?

My only concern with Dual Springs is the added stress on the rocker shaft studs that are in 'old' aluminum heads. I would like to run Single springs unless there is no way they will hold up.

What do you guys think?