Dual valve springs
#3
#4
Your valve spring pockets may need milling for the correct spring height to be achieved, and your valve guide may have to be machined for smaller valve guide seals to clear rhe inner spring
#6
#9
Spring pockets are close to the water jacket on Olds heads; don't recommend cutting the spring pockets. Plenty of dual springs available for you or you may want to look into the "beehive" springs that are available. If you choose dual springs your valve guides will most probably have to be machined for smaller outside diameter valve seals. Look to your cam manufacturer for valve spring recommendation.
#13
The UD cam in my engine is that lift and I used regular factory replacement springs with a damper, and the engine will easily rev to 5600+ RPM.
#14
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#19
A dual valve spring in most all cases requires the reduction of the seal area of the guide. The factory guide is around .590 and then when a seal is installed onto it, it will typically run interference with the i.d. of the inner spring on a dual spring. We frequently reduce the o.d. of the guide and install a .530 seal. This will allow for a dual valve spring. You can check out lots of tech tips and videos at Olds Performance and Machine on facebook. Thanks.
#20
A dual valve spring in most all cases requires the reduction of the seal area of the guide. The factory guide is around .590 and then when a seal is installed onto it, it will typically run interference with the i.d. of the inner spring on a dual spring. We frequently reduce the o.d. of the guide and install a .530 seal. This will allow for a dual valve spring. You can check out lots of tech tips and videos at Olds Performance and Machine on facebook. Thanks.
#21
Ditto what Ralph mentioned in post #15 above (if you can find them). They are considerably stiffer than the non W30 valve spring and should work fine up to .500" lift; and you can use stock valve seals with them. On a separate but similar note, if someone has the means to research this, I recall a Chevy 409 factory valve spring that had the same specs as the Olds W30 spring.
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