rocker arm shafts

[wyrmrider]

I use a solid brake cyl hone first so I can see if the lifter bore is bell or dumbell shaped
flexhone is great to put a pattern I'd remove sharp edge on oil galley first
you do not want to dingle up your balls

 

[Dibbons]

I wonder if some of us are using the wrong rocker shafts for ductile iron adjustable rockers? Just had a discussion on FABO and I was told the upper shaft in the photo is for stamped steel rockers and the lower photo is for adjustable rockers. Quite a difference in oil hole location and oil hold diameter. I found the adjustable rockers on both shafts, so I don't know who is right and who is wrong (or if it really makes a difference).

I don't see any mention on the aftermarket shafts advertising what they are made to fit (stamped steel, ductile iron, or both). I should have kept my mouth shut, probably just opened a can of worms here.

 

[Dibbons]

I had a heck of a time getting the ductile iron rockers off the shaft shown in the top of the photos: Found this on the internet, which may explain what happened (I thought they were just stuck from rust):

 

[gkent]

I ran Isky ductile iron rockers on stock shafts with no problem but back in the day the hot ticket was TRW replacement shafts which were thicker and machined.

 

[Mike67]

I just bought some grooved billet steel shafts from Stanke a couple of weeks ago. Didnt have any issues with my Promag bushes rockers
https://www.stankemotorsports.com/Products.cfm?pn=440RS&pID=55

 

[BSB67]

......you do not want to dingle up your balls

That's made me laugh out loud three times now.

To the OP, I simply dont know the answer to your question with today's materials of construction, and today's quality. I do know the material of construction for both the rocker and the shaft need to be correct for compatibility.

I also know that 40 years ago, if you used Crane, Crower, or Isky ductile iron rockers on standard shafts with even mild spring pressure there would be significant galling/material transfer. At that time chrome plated shafts were the solution.

 

[Glenwood]

Two years ago I went with shafts from Mancini, but the new iron rockers failed at the valve stems and were returned for a refund.
I'm now running roller rockers on new shafts and all seems good.

 

[69 GeeTeeX]

I’ve used Melling OE shafts and their made in Michigan. Not cheap Chinese crap.