Valve Springs

[motorparts92]

Does anyone know off the top of their head, the specs on stock 426 street Hemi valve springs? i know they are beefy, but are they beefy enough?

 

[Meep-Meep]

Beefy enough for what cam?

They should be single with damper and maybe 120 lbs on the seat. 440 Magnum springs are like 90-100 on the seat if I remember correctly, so a little more for the hemi makes sense.

 

[IQ52]

From the 1969 Service Manual

HP 383/440
Free length 2.23"
100-110# @ 1-55/64"
236-256# @ 1-23/64

Hemi
Free length 2.20"
110-120# @ 1-55/64" valve closed less surge damper
270-290 # @ 1-3/8" valve open less surge damper

 

[lewtot184]

i've got a set of those around here i've tested. i'll have to see if i can dig the info up. they're considered a high rate spring, build pressure quickly. one thing i found out is they won't take the lift mopar says they will. the bind up fairly quick like a stock magnum spring. seat pressure is around [email protected], open around [email protected]. i wouldn't use a .500 lift cam with them

 

[motorparts92]

the cam i just bought is a lunati with 494/513 lift 268/276. They are new springs, not used...so you are saying i shouldnt use them with this lift?

 

[lewtot184]

the cam i just bought is a lunati with 494/513 lift 268/276. They are new springs, not used...so you are saying i shouldnt use them with this lift?

check installed height, retainer to guide/seal clearance, and rocker ratio before using them.