Valvetrain weights?????
11-02-2002, 11:22 AM
#1
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Valvetrain weights????? When weighing the valve train components( Valves, lifters, pushrods, retainers, locks) should I measure the spring weights? I'll try to match up all the weights to within a couple grams from heaviest to lightest like my pistons/rods so one spring isn't working harder to maintain contact with the lobes or seat
LAter <img border="0" title="" alt="[Big Grin]" src="gr_grin.gif" />
<small>[ November 02, 2002, 11:28 AM: Message edited by: Bob2of3 ]</small>
LAter <img border="0" title="" alt="[Big Grin]" src="gr_grin.gif" />
<small>[ November 02, 2002, 11:28 AM: Message edited by: Bob2of3 ]</small>
11-03-2002, 11:36 AM
#2
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Re: Valvetrain weights????? Not the spring weight, but the spring load at the installed height is the thing to measure.
Springs of the same diameter and wire size and number of coils will have the same spring rate (lbs/inch), but may have different loads at a given height. As springs are repeatedly cycled, they don't lose rate, they lose load at a given height. How quickly they lose load depends on how severely they are used. Pro Stock valve springs might need changing after each run. But then opening a 2.25+ valve over an inch at 10,000rpm tends to be hard on a spring.
All the springs should be installed at the same LOAD when the valves are closed. This is achieved with shims under the spring.
Parts like valves, lifters, pushrods, retainers locks, etc. are all machined parts which rarely vary in weight from part to part, assuming they are all the same partnumber. Even springs from the same batch will be almost identical in weight.
Springs of the same diameter and wire size and number of coils will have the same spring rate (lbs/inch), but may have different loads at a given height. As springs are repeatedly cycled, they don't lose rate, they lose load at a given height. How quickly they lose load depends on how severely they are used. Pro Stock valve springs might need changing after each run. But then opening a 2.25+ valve over an inch at 10,000rpm tends to be hard on a spring.
All the springs should be installed at the same LOAD when the valves are closed. This is achieved with shims under the spring.
Parts like valves, lifters, pushrods, retainers locks, etc. are all machined parts which rarely vary in weight from part to part, assuming they are all the same partnumber. Even springs from the same batch will be almost identical in weight.