Re: Roller Rockers in Stock
 

The Isky ductile iron adjustable rockers have no advantage over the stock Max rockers. Both measure around 1.47. I have two sets of these and still run the same 1963 rockers I got with a stock Max engine in 72, Paul.

Re: Roller Rockers in Stock
 

Don't forget your MOPAR buddies that also get to run the Isky parts as a replacement to their 318/340/360 engines factory equipped with stamped steel rockers. I think you would agree there is a considerable durability advantage in using those Isky's over stamped rockers.

Re: Roller Rockers in Stock
 

Jeff, Holroyd's rockers are STOCK GM, the studs and adjusters are similar in material to the ARP rocker studs.

We can get by with the 7/16" stuff, there are even some fast cars still using 7/16" rockers. What we broke 2 years ago at Gainesville was an ARP rocker stud, it broke at the base of the threads. I was going to upgrade to the ARP Pro Series studs when a friend turned me on to Holroyd's stuff.

The rockers themselves will still fail the same as the 7/16" rockers, ask a couple of the real fast guys.

If you are willing to replace the rocker studs often enough (the ARP Pro Series studs are $100 or so) you can run the stock diameter studs and rockers. You MAY lose a little to deflection.

NHRA allows all engines to run aftermarket studs, and even convert to screw in studs when they were not originally equipped.

Some big block Chevy high performance engines came with 7/16" pushrods. We (as well as most I know) currently use 7/16" straight pushrods and GM guide plates.

Again, I'd LOVE to see a solution for the rocker problem so that guys with the less popular stuff could go buy good parts for a fair price. I DO NOT want to see cars parked.

However, allowing roller rockers will absolutely bring about serious unintended consequences, for the reasons I outlined earlier.

Re: Roller Rockers in Stock
 

As long as they do not allow shaft type rocker arms in applications that were not OEM configuration, and they do not allow stud girdles, then there will not be any measurable gain in power, just reliability.

Re: Roller Rockers in Stock
 

I do not agree. If you take an engine equipped with stock shaft rockers and large diameter lifters, and replace the stock shafts and rockers with 8620 or 8740 shafts and big roller rockers, you can EASILY exceed what can be achieved with stud mounted rockers and no stud girdle, even WITH roller rockers. Otherwise, there's be no market for stud girdles, and there'd be no shaft rocker conversions.

Re: Roller Rockers in Stock
 

Alan, there are only a few applications that use the shaft rockers: Mopars, Ford FE and Buick. The Mopars, both big block and small block, and the Ford FE's, are already running aftermarket adjustable iron rockers made by Isky or Crane. They are not stamped rockers like most OEM configuration. For Mopar applications, you can get a hard-chromed shaft, made of a heavier material that will not flex, at your local Mopar dealer over the counter. The Isky and Crane ductile iron rocker arms do not flex.

By the way, both the Mopar and Ford FE's, already have a big OEM lifters, and they also are fast.

http://www.iskycams.com/ART/products/69/384L.png
http://www.cranecams.com/include/sho...eading&id=1089

Re: Roller Rockers in Stock
 

I'm well aware of that. In fact, going back a few years, I was working on a Tunnel Port in a Shelby, and I learned VERY quickly about the strength difference between the stock replacement style rockers and the aftermarket roller rockers. There is a major difference, at least in my experience.

Re: Roller Rockers in Stock
 

So why do you need to spend 15,000 on a motor.There are a lot of racers that don,t have that much in there car.

Re: Roller Rockers in Stock
 

I was refering to competitive A/B/C cars. Sorry for not being specific.

What movie was that? "There is nothing stock about a stock car..." LOL

Re: Roller Rockers in Stock
 

And some of those guys are the guys that bitch when there car isn't fast. They don't work on them and they want rules changed so it is easier for them to compete with the guys that put in double the effort and money. If you take the time to learn and work hard you can build a combo to run fast for less, but if you know nothing and don't want to learn then you are going nowhere.