[Skip Fix]

Years ago with Lloyd Coulson dynoing his 455 HO about every other pull one of the aluminum Erson rockers would crack!
I've had good luck with the old Norris SS, HS 1.5s and 1.65s and the Crowers-even the 1.8 0.090 offset trunnion BBC on my Pontiacs.

[Skip Fix]

Years ago with Lloyd Coulson dynoing his 455 HO about every other pull one of the aluminum Erson rockers would crack!
I've had good luck with the old Norris SS, HS 1.5s and 1.65s and the Crowers-even the 1.8 0.090 offset trunnion BBC on my Pontiacs.

[Formulajones]

Originally Posted by grivera

Larry - a you post a link to the Ultra Pro Magnums? I can’t find them.

For what ever reason Comp doesn't make them in the Ultra Pro Magnum for Pontiac but they do make the chrome molly Magnum for Pontiac. It's a nice alternative that I'll use when I can't get the Crower, and they are priced reasonable at about $320 a set.

https://www.compcams.com/magnum-roll...-65-ratio.html

[Dragncar]

Originally Posted by Skip Fix

Years ago with Lloyd Coulson dynoing his 455 HO about every other pull one of the aluminum Erson rockers would crack!
I've had good luck with the old Norris SS, HS 1.5s and 1.65s and the Crowers-even the 1.8 0.090 offset trunnion BBC on my Pontiacs.

Interesting, maybe those old Ersons are not all that great. I used to run Erson stuff and I would call their tech guys asking them if they would make the steel pedestal mount rockers for Pontiacs like they had for Chevy's. They said it was in the works, never happened.
I just need a good set of 1.65s for my rocker arm collection and the Ersons will never get run. I got them for free so I thought I would try drilling them out to 7/16".
It does not really work. Very,very hard metal, I had to sharpen each drill in the step process at least 10 times. Even when I finally made it to 7/16 you could not get a 7/16 rocker stud through them. Have to drill past 7/16. With all the coolant, filings that went through them the 2 I did are junk.
Wish I would never had tried it but they were free. Someone could have used them on something like a .500 lift cam with a stud girdle.
I have some Butler aluminum 1.5 rollers, Harland Sharp 1.5 rollers, Norris 1.6 SS rockers, Crower 1.7 aluminum rockers and Crower Endura SS 1.7 Shafts.
Its like I have a Pontiac roller rocker fetish or something.
Guess I am going to have to buy those Comp steel rollers !

[grivera]

Originally Posted by Formulajones

For what ever reason Comp doesn't make them in the Ultra Pro Magnum for Pontiac but they do make the chrome molly Magnum for Pontiac. It's a nice alternative that I'll use when I can't get the Crower, and they are priced reasonable at about $320 a set.

https://www.compcams.com/magnum-roll...-65-ratio.html

Thank you

[Skip Fix]

My IA 500 has Crower SS shafts the rockers look a lot nicer than the aluminum shaft rockers i have seen. although for the E heads I basically had to design to correct exhaust offset to swap on . at least they Even Steven swapped them.
Had to notch the mounting brackets for the studs also.

Here are Comps SS on the 409. not quite as big a trunnion bearing as Crowers.

[Cliff R]

The end user here needs to realize that when you "upgrade" to roller rocker arms they may not really me much of an upgrade.

First you add a LOT more places to wear out. Needle bearings for one if you go to full rollers, and a hardened pin with a hardened roller on it.

Not to mention that they can fatigue where the pins go thru and the pins can "walk" out of them. I've seen that happen WAY too many times for my liking.

You also add a lot of weight. Weight in the valve train is NEVFR a good thing are REQUIRES additional spring pressure to keep things in check at high RPM's. In the 45 plus years I've been doing these engines I still have yet to see a failed factory stamped steel rocker arm in a Pontiac or Chevy build. I have seen several Mopar 383's and 440's have the pushrod poke a hole thru them, but to date never a single failure with a Pontiac rocker arm. I even ran stamped steel rockers in my 1965 Chevy Nova SS's SBC engine spinning it to 7000rpms shift points and thru the traps at 7500rpms. I raced it for years like that and no issues with rocker arms even with the pretty hefty spring pressures I was running....FWIW

We are also trusting these offshore manufacturers to get the hardness of the pins on par with the hardness of the rollers. That is where the the PRW stainless steel full rollers fail miserably. They told me they knew about the issue and corrected it around 2009-2010. Even so how do we know as a consumer that it really happened, or that they did cycle testing on them to find out if the upgraded pins/rollers made the grade in long term service. Personally I highly doubt if they did anything based on the high failure rate with those parts.

The worst part here as I mentioned is that if you have hydraulic lifters the plunger travel takes up the wear and they don't get noisey until worn slam out. At that point they have put a BUTT-LOAD of metal into your engine.........

[Stan Weiss]

I guess I must have run something different in my SBC as I have broken stock rocker arms.

45+ years ago, Engle (238) solid roller cam in SBC. Broke Stock rockers. The M/T rockers worked perfectly. The cam used dual valve spring and a rev kit. Don't remember what spring pressure was, but back then was a cast core, tight lash cam. Yes, it was for me street-able. It was driven from Phila PA to Nashville Tenn.

Stan

[Jim Moshier]

I ordered these from CompCams and they may be 8620 chrome-molly but I received the roller-tipped rocker 1.65. Not the rocker arm pictured in your/their link. Not a fan of the roller-tipped arms only and not full roller I will be sending them back..... especially for $320.

https://www.compcams.com/magnum-roll...-65-ratio.html

[Sirrotica]

To add to what Cliff has posted about OEM stamped rockers, all the race engines I've built, none had roller rockers, because they weren't allowed per the rules. The Pontiac arms had the correct hardness of all the components, and wore very well. I remember reading that the guy that designed the rocker setup (Clayton Leech) specified the the components were to be cyanide case hardened. Likely a process that is no longer used because of the EPA. The piece ends up with a very hard outer shell for wear resistance, but still maintains the ductility of the core material.

I had one time bought some Manley aftermarket 1.65 rockers because the OEM ones were quite expensive. They promptly pulled the ball down through the stamping, so much for saving money on aftermarket parts. I assume there was no case hardening on those parts, that the OEM parts have.

I ended up throwing them away, and bought the paid through the nose at the dealer for GM parts. Since the GM parts came with the 11/32" pushrods, I also had to upgrade the guide plates to RA IV too. I've run the 1.65 OEM parts on at least 3 engines to date, the've survived perfectly, little to no wear. I've used the OEM rocker arms, and pivot balls on solid cams, as well as solid roller cams with no appreciable wear, and more importantly, no failures.

Oval track engines tend to need to have to have reliable parts due to the fact they are run in a race environment for a much longer period of time. They run for many laps at one time, rather than 10-15 seconds such as drag cars tend to. One season on an oval track engine is much more run time than a drag car gets. They also run at a high temperature for much longer periods, showing how reliable the parts are in an endurance environment.

Since the 70s, all The Pontiac engines I've had, I've never owned a set of roller rocker arms. I've pretty much torture tested the OEM rockers, and never had failures. They've worked on cams into the area of .550 lift, and I realize that as lift is increased, they likely will become a liability, rather than an asset. but at my cam specs they have worked flawlessly. Something to be said for the KISS theory.

[Formulajones]

I've had the factory stamped rockers fail. Had one bust right through the fulcrum on a very mild hydraulic flat tappet. So they do fail but you won't hear of it too much anymore these days for a couple reasons. One is there are so few Pontiacs on the road and the ones that are around are seldom driven so the sample size is just too small to make any comparison. Two, many classic Pontiacs still around have had some sort of performance oriented build at some point in it's life and my bet is likely most now don't even sport their original rocker arms anyway.

Worrying about something failing can honestly apply to most anything you buy. Any part of your engine can decide to fail and any given time, even the more expensive stuff. Ya just have to avoid the cheap parts on the market and cross your fingers the more expensive stuff holds up. It's hot rodding. Roll with it.

[Cliff R]

LOTS of the "high performance" parts being sold for these engines aren't going to make it in the long run, but these days there are very few "long runs" with these engines.

You simply aren't going to find out how bad many of these parts are because a high percentage of the folks using them are lucky to put 1000 miles on one of these cars in the next ten years.

I have yet to pull a used engine down that was built with a set of Comp Cams roller tip rockers that didn' have the bodies in the fulcrum area turned blue or even black from the heat they produced wearing themselves in. None had failed, but all were heavily gauled and had put some metal into the assembly.

Same with the PRW stainless steel rockers, none failed, all heavily worn at the roller ends where the pins go thru them.

Makes one wonder how many engines are out there having to filter all that ground up material from failing parts but the engine is still running OK?

There are a LOT more parts out there that don't make the grade that frequently get used in these builds. Cheap double roller timing sets with cast iron sprockets and low quality chains top the list. To this day I can't understand how anyone choosing parts for their engine believes that some low-end double row bicycle quality chain set is any kind of upgrade over a 3/4" wide factory style Morse chain from Cloyes or Melling. IF you are going to cowboy-up in that area at least buy the very best that Cloyes has to offer instead of saving $50-60 and buying bottom of the barrel crap......FWIW.....

[PAUL K]

Nothing wrong with stamped rockers other than they are slow moving and don't deliver the advertised ratio. I would never consider them an option on a solid roller set up or anything with a lot of lift.... There are much better options.

[Steve C.]

A tid bit in support of Paul's comment ?

"First of all, rocker arms rarely maintain the same ratio throughout the entire valve-lift curve because the rocker arm moves in an arc as it generates lift. Roller rockers do a good job of maintaining their stated rocker ratio throughout the entire lift curve, but the same is not always true of stock-stamped factory or budget stock replacement rocker arms. These pieces often test far short of their rated rocker ratio."

Source:

https://www.motortrend.com/how-to/14...amped-rockers/

..."it's well known that the inconsistencies of stock rockers and the friction and heat they create mean there's power lost with them. "

https://www.motortrend.com/how-to/su...ker-arm-ratio/


.

[Formulajones]

Originally Posted by Cliff R

LOTS of the "high performance" parts being sold for these engines aren't going to make it in the long run, but these days there are very few "long runs" with these engines.

You simply aren't going to find out how bad many of these parts are because a high percentage of the folks using them are lucky to put 1000 miles on one of these cars in the next ten years.

I have yet to pull a used engine down that was built with a set of Comp Cams roller tip rockers that didn' have the bodies in the fulcrum area turned blue or even black from the heat they produced wearing themselves in. None had failed, but all were heavily gauled and had put some metal into the assembly.

Same with the PRW stainless steel rockers, none failed, all heavily worn at the roller ends where the pins go thru them.

Makes one wonder how many engines are out there having to filter all that ground up material from failing parts but the engine is still running OK?

There are a LOT more parts out there that don't make the grade that frequently get used in these builds. Cheap double roller timing sets with cast iron sprockets and low quality chains top the list. To this day I can't understand how anyone choosing parts for their engine believes that some low-end double row bicycle quality chain set is any kind of upgrade over a 3/4" wide factory style Morse chain from Cloyes or Melling. IF you are going to cowboy-up in that area at least buy the very best that Cloyes has to offer instead of saving $50-60 and buying bottom of the barrel crap......FWIW.....

I agree, I saw those issues with those Comp roller tip rockers turning blue way back in the 1980's on an engine my friend was running on the dyno that day. Another hydraulic flat tappet using Rhoads lifters, not crazy spring pressure. Literally 4-5 pulls and when we checked things over, all the rockers were blue from heat. Comp was made aware of that issue way back then, and as far as I know it was never corrected. The grooved ball they used in those things didn't fit very well and rode up on the sides. Poor quality, and that was long before all the "made in China" complaints you hear now, long before the internet.

I'm probably one of the few on this forum that actually daily drives these old cars so when it comes to durability and longevity, I feel I have a pretty good handle on what's working and what isn't. However nothing is immune to failure and I think we can all agree on that.
Very few here drive their cars enough to even see a problem, or it may take years to show itself. This isn't always the case but generally, ya just gotta stay away from the really cheap stuff. If the price is the cheapest there is probably a reason for that. lol

Unfortunately I run into people in this hobby every single day that are always trying to save a buck or they don't want to pay the higher price for something. While I can't fault a guy for having a budget, that's just life, however it seems to come back and bite them later. This car hobby really isn't for the faint of heart, it never has been, but that's especially true these days.

[lust4speed]

Have found the same blued stamped Comp rockers that Cliff has on every set I have removed and discarded. Not every once in awhile but every installed set. These are engines coming in to me that had fairly mild hydraulic flat tappet cams and mild spring pressures.

[Dragncar]

Whitmore told me long, long ago to stay away from Comps roller tip rockers arms. Said the build up heat, turn blue and put metal into your engine.
Also said the stock rocker arms were actually in the 1.4s as far as ratio.
He is the one who suggested Norris rockers. Best 260$ I ever spent.
They are 1.6 advertised but he told me every time he checked them they came in at 1.65 ratio.

[GTOLou]

Originally Posted by vicgto

I started noticing a valvetrain ticking sound recently, pulled the valve cover and saw a rocker tip roller pin almost out.Attachment 620119 . I also saw 2 other rockers with loose pins. Needles to say I've lost all confidence in these rockers

lol - I lost confidence over 10 years ago. I would NEVER use those.

Someone mentioned Scorpions...with an HR set up, I've never had issues w/ Scorpions. Again, HR. Not sure of SR.

[Cliff R]

Tried one set of Scorpion full roller rockers here and this is what we ended up with. 13 out of 16 cracked in exactly the same manner......and YES the engine was using higher springs pressure and a full "race" set-up. I've been chastised for using those rockers in that application but aren't we supposed to "upgrade" from stock rockers when we install solid roller camshafts, stronger valve springs and start spinning the engine past 6000rpms?........

[lust4speed]

I'm not a fan of Scorpion rockers. Had one rocker in the set that should have been caught in even a cursory inspection at the factory since part of the mold gave way and the center slot was almost solid aluminum. Plus Scorpion seems to think that adding bulk to the rocker is the only way of increasing strength. Take a look at the photo above and notice the distance from the pivot fulcrum to the top of the lifter is massive. It is the least likely rocker to clear any valve cover except for the tall 3". If Cliff is breaking those, then all that excess aluminum isn't doing any good.