coil bind on a 351C

[porkchop]

i am goind from a 280H with .530 lift to a 284Xe with .584/.588 lift. the valve springs have about 3,000 miles on them and they came in the comp cams 280H kit when i got my motor rebuilt. so will i need to replace the valve springs and/or will i need to get the heads machined to recess the valve springs.

 

[shotsy]

If you put the 924-16 springs in with the 280H you should be ok moving up to the 284xe cam, the optimum spring acording to comp cams web site is the 930-16.
Here's the link to all of the info


http://www.compcams.com/Technical/CurrentCatalog/HTML/92-97.asp

 

[D.Hearne]

If you heads don't already have screw in studs and guide plates to allow adjusting the lash, you'll need to do that also with that cam.

 

[69 Rustang]

You will need to change springs to the matching set from Comp Cams otherwise you will have coil bind and bend your pushrods (or worse). I know because when I was younger I made that error.... As for needing to do any machining--none should be required, but do check your rocker pivot to ensure that you do not get binding in the rocker arm at the slot. As they are bolt down pedistal rockers, you do not need to put in studs.

 

[Mach1steve]

no studs

I agree, studs should not be needed, but upgrade to the recommended "premium spring for that Cam.
Valve float & spring bind can be catastrophic to your engine.
I had to machine the valve spring seats in the heads slighly larger when I went to a .560 lift Cam, but it was a different Cam maker (Cam Research), because the spring Outside Diameter was larger than stock springs.

Mach1steve