How can Yella Terra rockers help
09-11-2003, 02:58 PM
#21
Re: How can Yella Terra rockers help The YTs are not shaft mounted rockers.
I think the YTs quiet down the valvetrain because they disturb some kind of resonance that is occuring in the valvetrain with normal rockers.
I dont think that the average mechanic understands quite how much a valve does NOT follow the perfect lobe path in a valvetrain. I once saw testing of Comp Cams lobes on a device called a "spintron" which simulated RPM given a cam, a lifter, a pushrod, a rocker, and part of a head complete with spring, retainer, locks, adn a valve. The pushrod was vibrating and arching everywhere and the printout showed the valve bouncing off of the leading face of the lobe at some rpms, and then bouncing off the seat a bit at other RPMs. These were not things only happening above 6000 rpm. I really dont think people appreciate how clap-trap our valvetrains are, how much stregth they require from all components, and how many resonances and floats and bounces are considered normal. Its not pretty. Having said all that, it is quite easy to improve on this with better rockers, stiffer pushrods, lighter valves, stiffer springs, etc.
Better rockers can mena stiffer or in some cases lighter, or in even some cases rockers that are dampening some particular resonance, which I think the YTs do.
Pre supposition until someone Spintrons a LS1 valvetrain.
chris
I think the YTs quiet down the valvetrain because they disturb some kind of resonance that is occuring in the valvetrain with normal rockers.
I dont think that the average mechanic understands quite how much a valve does NOT follow the perfect lobe path in a valvetrain. I once saw testing of Comp Cams lobes on a device called a "spintron" which simulated RPM given a cam, a lifter, a pushrod, a rocker, and part of a head complete with spring, retainer, locks, adn a valve. The pushrod was vibrating and arching everywhere and the printout showed the valve bouncing off of the leading face of the lobe at some rpms, and then bouncing off the seat a bit at other RPMs. These were not things only happening above 6000 rpm. I really dont think people appreciate how clap-trap our valvetrains are, how much stregth they require from all components, and how many resonances and floats and bounces are considered normal. Its not pretty. Having said all that, it is quite easy to improve on this with better rockers, stiffer pushrods, lighter valves, stiffer springs, etc.
Better rockers can mena stiffer or in some cases lighter, or in even some cases rockers that are dampening some particular resonance, which I think the YTs do.
Pre supposition until someone Spintrons a LS1 valvetrain.
chris
