[mgarblik]

Originally Posted by Cliff R

Ran ONE set of Scorpions and cracked 13 out of 16 of them. They didn't fail completely but they were a ticking time bomb.

I was being kind about the PRW's above but the failure rate was 100 percent and PRW didn't replace them. Not surprising as with most of these parts you get a really good "Arkansas Warranty" when you buy them: IF you break them in half.....you get both halves!.....LOL

Anyhow, we do NOT get reliable feedback on most of these "high performance" parts. This simply happnes because most of these cars won't get but a couple thousand miles put on them in the next 5-10 years.

When it comes to roller rocker arms the ONLY ones to date I've not had issues with where Crower Enduro, Crane Gold Race and Harland Sharp. For all the others we've put in service they either cracked, broke, or burnt up the needle bearing or roller end of them.

I see the SAME issues with other parts commonly used in these engines and have responded accordingly. I completley quit using "double roller" timing sets for the same reason. ALL of them failed or get WAY too loose for my liking, and some in pretty short order. I know, I know, about the time you tell someone that your Rollmaster timing set failed in a couple of years in your 455 a dozen folks come on and tell you they have 250,000 miles on one and it's tight as a banjo string.......FWIW.......

Had a 70 SS 454 Chevelle come in about a year ago with the "blue death" Scorpion rocker arms . 11 or 16 cracked just like that. Unfortunately, 1 of the 16 had the pin come all the way out and it dropped a valve. Amazingly, it just beat the hell out of the head and dinged up the piston and nicked-up the cylinder a little. Was able to save the head by replacing 2 seats and some grinding/clean-up on the rest. It was a hydraulic roller engine. 150 lbs. on the seat, nothing crazy. I will not guarantee any stud mounted aluminum rocker arm for this reason. The replacements on this engine were Crower stainless steel. Cracked like Cliff's pics is VERY common across the line for aluminum rockers of this general shape and design. Probably Harlan Sharp, made in Ohio, would be the best of this general design. Even if I was using them, I would pop the valve covers off every year and take a peek.

[chuckies76ta]

Thanks for the info Mike.

[Cliff R]

I had a long time ago customer call me a few days ago and said that two of the Harland Sharp roller rockers we installed on his engine had the rollers side-load and dig pretty hard into the aluminum. I haven't seen them yet put he ended up pulling the heads and is bringing them here for inspection.

So we may have our first Harland Sharp roller rocker arm failure, will update or start a new thread once I sort all that out.

In any case the list of what I'd use here is getting smaller and smaller by the minute!........

[jamaca85]

hearing all that stuff of the scorpion rockers...i guess i got the only good set out there been running them for over 5 years no issues(1.5s) i guess sometimes stuff breaks and and sometimes it dont..lol

[TxSportCoupe]

All fine examples of why I run stamped steel rockers. I haven’t had one fail me in over 40 years of doing this. Only ticking I hear is the sweet sound of the Rhoads Lifters and I take great pleasure in knowing I’ll never pick needle bearings or roller parts out of my oil pan. Worth all 3 horses lost and every bit of the minuscule lifetime valve tip wear.


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[n20ta2]

Originally Posted by TxSportCoupe

All fine examples of why I run stamped steel rockers. I haven’t had one fail me in over 40 years of doing this. Only ticking I hear is the sweet sound of the Rhoads Lifters and I take great pleasure in knowing I’ll never pick needle bearings or roller parts out of my oil pan. Worth all 3 horses lost and every bit of the minuscule lifetime valve tip wear.


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Probably good for your build but I cant run stamped steel rockers with my spring pressure.

[AG]

I run HS 1.65 rockers on my race car with 700# open pressure and they haven't had any issues after over 100 runs running up to 6700 rpm. If I was running more RPM or open pressure I'd switch to shaft rockers.

[PAUL K]

Many years ago we had a few failures with stamped steel 1.65 rocker arms, but that was with the Sealed Power replacements. I talked a customer into using original RAIV rockers due to the previous aftermarket rocker arm failures. He had a pushrod poke right through the cup on the factory rocker arm. The lifter popped out of its bore, slipped between the cam and valley area, snapped two SD455 rods in half, one rod came up and broke the cam the other rod went down and made a hole in the block.... From that point on I was a bit cautious in regards to strongly recommending parts.

[mgarblik]

That sounds like my kind of luck right there. It's never. "wow, you really go lucky finding that before disaster happened". It's always, "damn, how in the world could all this engine damage possibly happen?"

[chuckies76ta]

I decided to buy a set of Crower 1.5. And a set of Harland Sharp 1.5 S6001HD

[AG]

Those are nice and $$$.

[chuckies76ta]

Originally Posted by AG

Those are nice and $$$.

Yes they are, but that's the way this stuff is. lol

[zippy]

FWIW I have a bare alum set of Scorpion 1.65. No annodizing at all. They have been in about 20,000 mi I would est. Comp 995 springs. No issues. Just rebuilt and checked al due to another flat cam from unsure causes

[Formulajones]

Ive broken oem stamped steel on a hydraulic flat tappet in a sbc using a common Z/28 spring.
Wife came home one day and running horrible. Found 2 broken oem rockers. One pushrod and the other at the rocker stud.

I replaced them with 2 more oem stockers and daily drove that engine another 2-3 years.

Just never know, this stuff can go at any time,. Doesn't have to be aftermarket Chinese

On the flip side Ive had Harland sharps on one engine for 25 years and almost 100k miles without a hiccup using a hydraulic flat tappet.

My 454 has crower stainless for 35 years on 3 different engine combinations, one with solid roller springs and this last combo for 25 years on a hydraulic roller with 150 on the seats. Those rockers just keep going.

Dad ran harlands on his last 455 for years and even came home one day with a broken rocker stud. Then used those same harlands on his next engine with a solid roller and 240 on the seats for the next few years. I swapped them for crowers a few years ago just because. They were still working fine

[chuckies76ta]

Little comparison just for the hell of it. . Crower on left. PRW on right. These were PRW bought years ago. I'm surprised at the weights. Crower on bottom in last pic. Look at the size of the trunnion on Crower.

[Formulajones]

Comp makes a very similar stainless rocker but I've never compared the trunnion to the Crowers, I just always use the Crowers.

There are a ton of those Comp Stainless rockers in service though.

[chuckies76ta]

Good to know. Thanks

[Formulajones]

Originally Posted by chuckies76ta

Good to know. Thanks

Here they are for Pontiac. Correction they are Chrome Molly

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


Theyalso make a pro magnum version too for some applications where it appears they took some weight out of them in key areas and they advertise what they call "an oversize trunnion". They also guarantee the rocker body for life against breakage and are rated for 850 lbs. open spring pressure. LOL Rockers like that should last the life of the engine with a mild street cam and mild spring pressures.