Rocker arm questions.

[KillerKittyCat]

Having had to replace an intake valve that the machine shop "thought" would work I now have 135~140 psi compression on all eight. As a result the intake rocker is damaged.

Everyone wants to sell me "roller-tip" rockers. Whats the advantage? I am trying to keep this car as stock as possible. If it ain't broke don't touch it right?

This is the early 289 with non-rail rockers.

Thanks.

 

[mustang70]

The roller rockers reduce wear on the valve tips by getting rid of the side loading that comes with the rocker tip sliding over the valve tip. They also tend to be stronger then the stock rockers so the valve gets all the lift from the cam. But if your engine is stock, I'd stick with the stock rockers.

 

[D.Hearne]

Having observed first hand both types of rockers in operation, I don't think roller tipped rockers give much of an advantage from the roller tips alone over flat tips. The flat tips also "roll" across the valve tips, not slide. The major benefit from roller tipped rockers come from their construction, they definately have an edge over stamped steel fulcrum types, but this doesn't ring true for the early 289 rockers that are cast , adn thus are stiffer than stamped steel ones. If you really want to see a HP gain, then use needle bearing fulcrums over the ball types. If you need a replacement for that damaged one, lots of the older parts houses used to sell them individually.

 

[D.Hearne]

Having observed first hand both types of rockers in operation, I don't think roller tipped rockers give much of an advantage from the roller tips alone over flat tips. The flat tips also "roll" across the valve tips, not slide. The major benefit from roller tipped rockers come from their construction, they definately have an edge over stamped steel fulcrum types, but this doesn't ring true for the early 289 rockers that are cast , adn thus are stiffer than stamped steel ones. If you really want to see a HP gain, then use needle bearing fulcrums over the ball types. If you need a replacement for that damaged one, lots of the older parts houses used to sell them individually.