When do roller rockers become necessary?

[838]

At what lift do roller rockers become necessary. Looking at using the tman625 for a 117" build.

[Pirsch Fire Wagon]

They are used for a couple purposes. But, almost always in conjunction with other components. i.e. Heavier Springs, High RPM, Noise Reduction in Power Builds - actually makes more noise in stock builds. and when trying to squeeze the last bit of Horsepower available. Themselves, they provide little or no improvement. Anywhere a standard stamped Rocker wither could not keep up or caused decreased (inadequate) lubrication. They provide a more stable environment.

[Don D]

Not needed, in your case, but I also would not advise the cam change.

[MikeL]

I have Roller Rockers on my 124 with S&S 640 cams. I have standard rockers on my on my 98 with S&S 625. I notice a little tick on the 124. Both have rocker lockers.
It's not so much the lift but the spring pressure. The roller glides over the valve stem causing less stress on the guide.
Back when I was drag racing I had a cam that required some obscene installed seat pressure. There were no such thing as the Bee Hive spring then. I had standard roller rocker arms. I had to install jessel rocker arms to stop the valve guides from being worn in half.

                                                                                                       MIKE

[838]

Not needed, in your case, but I also would not advise the cam change.

Not for my 117"!!! She's lock and keyd! Had a buddy roast a 110 drop on kit from running it on a base map. He wants to stay under 10.5 and has the 625s on the shelf. He was going to install them on the 110" eventually...

[Don D]

I have used it with my pro heads at 110", oem casting ported, and it works well.

[prodrag1320]

we use them on .625 up here