88305tpiT/A

iTrader: (2)

So I am in the process of enlarging the chambers on some world S/R torquer 76cc heads for my 383 and I found 4 broken spring dampers (the coil inside the main spring). All of them broke about a half inch of one of its ends off. Needless to say I will have all the springs and retainers replaced and guides checked when I get the valve job done.

These springs were fine with the stock cam but obviously something caused them to fail. The cam I put in when I built the motor a year ago is a Comp 260/264 .474/.474 extreme 4x4. Comp recomends 981 springs for it but those seemed like essentially the same spring as the ones that come on the world heads assembled.

other stuff that might make a difference: Trickflow pushrods, comp retrofit roller lifters, comp pro mag 1.5 roller rockers.

What would cause all those dampers to fail??

Thanks for any help or anecdotes :-)

mnorton

My S/R torquers did the same thing! Four of the dampers broke after about 2000 miles. Several of the umbrella seals were chewed up as well.

I am sure that it was due to the fact that the springs were shimmed up too high. They had shimmed them up to the point that the springs had no pocket to seat in, thus they moved around enough to break the dampers and destroy the valve seals.

mcbchild

iTrader: (1)

Usually over revving the motor with break the springs/dampers. I broke 2 dampers also on my WP sportsman 2 heads. Be careful because this will also cause valve float.

88305tpiT/A

iTrader: (2)

definately not over reved but the springs were shimmed up pretty high.

mcbchild

iTrader: (1)

I thought for sure I didn't over rev mine also, but this has always been an issue with flat tappets. One time is all it takes. Maybe the shimming was too high and the dampers ened up binding.

88305tpiT/A

iTrader: (2)

not a flat tappet - retro roller.

88305tpiT/A

iTrader: (2)

guy at machine shop said my cam caused this. Not that the springs were any good to begin with but the cam profile was very agressive.

I have a 4x4 hydralic roller from comp. Machine shop says they use this lobe sometimes in lift limited classes and its REALLY hard on springs cause the ramps are so agressive for a hydralic roller (heavy) valvetrain. He didnt even recomend the 981 spring part number that comp does on their cataloge. Said hes seen those break plenty of times under 5000 rpm usage.