Ductile rocker arms

[5.7 hemi]

Got a set of Erson rockers and I'm sending them to Rock Arms Unlimited so they can be bushed. Also getting the rocker shafts they have with the banana grooves in them.

Not too sure how these things lived without a bronze bushing all these years, but no one will sell shafts to me if the rockers aren't aluminum or bushed. Those vendors are saving me a major headache and I learned something, so I'm good with it.

 

[gkent]

An iron unbushed rocker on a steel shaft is no big deal. Most wear or galling is a result of debris in the oil, not friction. That said, there is a limit to how much cam and spring pressure they will tolerate. But I can't see someone refusing to sell you shafts !!! One of the best shafts to use with those back in the day were TRW stock replacements.

 

[5.7 hemi]

I agree, but I'm gonna play it safe and bush them.

 

[5.7 hemi]

"Refused"probably wasn't the best word to use. Sure, they'd sell me the shafts, but after hearing their "sales speech", I thought otherwise.

 

[66Satellite47]

I ran a couple sets of Isky ductile rockers, unbushed. Got at least 3 -4 seasons out of them with the TRW shafts, cut the banana grooves myself. They did gall with time, .600 to .645 lift cams & 450+ lbs open pressure. Got 10 years out of Crane gold unbushed aluminum rockers with .660 to .690 roller cams & 600# open pressure. Had a set of unbushed Crane duplicate ductiles that galled after a couple thousand street miles & 45 strip passes. The original owner had overtightened the shaft hold downs though & deformed the shafts. I'm sure you'll be very happy with the bushed setup.