Roller rocker choice for HYD rollercam/for High Miles-Full life
If the geometry is right they will go a long way. The biggest rocker failure is from incorrect geometry. Simple as that. Second in line is not enough idle oil pressure. Anything below 35 pounds at a hot idle will almost guarantee the rocker will grab the shaft.
I’ve seen the best of rockers break in short order because the geometry was off. That’s why I said to contact Mike at B3. He can set you up with a geometry correction kit that works.
IIRC he can even Bush those rockers (which is what I’m going to have him do as I have the MP aluminum rockers which are the same as the Crane rocker) and I’m going to have him convert them to a cup adjuster. The geometry is a bit better with the cup adjusters.
FWIW, for my entire life I’ve said a steel rocker is better than an aluminum rocker. The problem is the junk **** Chevrolet “racing engine” is such steaming pile of crap with its cheap assed stud mounted rockers, and because it’s so much cheaper to use aluminum the whole aftermarket world, thanks to brilliant marketing was sold the aluminum rocker. It was a cheap fix for a piece of **** design.
You rarely see stud mounted rockers on a Chevy any more. It took 4 decades for the GM crowd to wake up but any decent GM engine is running shaft mount rockers. And some of the best “minds” in the business spent many thousands of dollars (or more) converting Chrysler stuff to ball/stud rockers.
I know there was a ball/stud 383 and IIRC a ball/stud hemi. They conveniently love to forget that sad history in trying to prove GM had a better idea. Even the highly respected Smokey Yunick said the SBC was a “relatively reliable high speed turtle”. Literally hundreds of thousands of R&D hours and tens of millions of R&D dollars later and they use shaft rockers.
Ok, my rant for the day is done.
(Rant)! Yellow Rose- That is the most refreshing, to the point, spot on, my argument, bit of automotive design savvey-savey-savv-owell. I have had the pleasure reading in a very long
time. But you missed one very import'nt bit. The 1500+$$$ to teach that valve train the
correct valve to open and when. LOL
I need to look up Mike at B3 as you mentioned. Sounds like he might have what I have been
making myself in the past.
Here is how I setup my valve trains in the past. Please chime in to add or poke a hole in this
with your input.
My train of thought goes from the valve to cam not the other way. For starters lifters are
heavy, rollers more so, just keep that in mind here. Ok, first I work the geometry from valve to shaft for min sweep, .040 or so. Side to side is a given. Shaft to pushrod, push rod long-adjuster
short, but try for min max lift angle at push rod/adjuster point. Remember heavy lifters, I have the cam ground with less lift and then make it up with rocker ratio. The springs job also has to keep the heavy lifter in contact with the cam lobe. Simple math-1.5 ratio rocker, 50lb force from spring on rocker tip is 100lb back down to heavy lifter. 1.7 ratio rocker, 30lb force from spring
='s 100lb to lifter. Something to think about.
Things to think on.
1.5 rocker is more forgiving with non-ideal geometry. To short a push rod-broken adjuster.
A little more forgiving?
1.7 rocker is less forgiving? But with correct push rod length and rocker arm setup you have
better rod/adjuster angle. And less heavy lifter travel, less chance of oil ports on lifter out of the bore.
You have all heard high ratio rockers are not as stable. Yes it is true----for the 90% that just bolt stuff together. For the other 10%--YAH BABY that runs good.
For the other 90% not willing to do the work refer back to the (Rant). It poked me to write this
and I hope for some more discussion.
Thank you all,
Rick
