#21  
Old 01-15-2021, 06:43 AM
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Any of the stainless steel rockers that a few of the top Cam company's make are good and long lived also just to be fair.

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Old 01-15-2021, 08:36 AM
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I've strayed off the path a couple of times and either cracked, broken, or ground up every single set of "offshore" rockers arms we've put in use.

I still remember the very first set of "rice" made rockers we tried and the pins "walked" out of the roller tips before we made the first pull on the dyno!

The companies selling them aren't going to do so much as replace them and even if they did I'd sell them on Ebay.

IF you are looking to upgrade from stock stamped steel rockers get off some extra money and buy from the top of the pile.......FWIW.......Cliff

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  #23  
Old 01-15-2021, 11:24 AM
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About 2 months ago, I had a 70 SS454 Chevelle towed to the shop with major engine damage. Engine had 2800 miles on a $7000.00 rebuild. Turns out the guy was super lucky. Chinese aluminum rocker arm failure. Axle pin worked out, broke the aluminum out of the tip end, dropped a valve, bent it like a pretzel, bent 2 push rods, shattered the valve guide, beat the hell out of the seat, sent metal fragments all around the one head. Fortunately, the engine was idling in a car show parking lot when it failed. I removed one head, rebuilt the head, put it back together along with a new set of Crower STEEL rocker arms. No major damage to the engine itself other than a few rat bites on the piston head, combustion chamber and intake port. Point of the post: Most of these Chinese rocker arms do NOT have a positive method for retaining the axle pin in the tip. They have a drilled clearance hole in one side and a tiny Knurled hole on the other end. The pin is inserted and a light press is applied to the pin to push it through the knurl in the aluminum. It's a ticking time bomb. There is no way the pins will stay put through millions of cycles. I inspected the rest of his rocker arms and 11 of the remaining 15 rocker arms had the pins moving out toward a similar fate. I know nothing about these Speedmaster rocker arms, but after looking them over, I couldn't find a single picture or text that mentioned how the pins are retained. There is no way I would use ANY aluminum rocker arm that doesn't have a positive retention method on the pin end. Jesel uses snap rings. Other less expensive designs swedge the pin on the outside. Pushing the pin through and hoping the termites hold it in there is non-starter for me.

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Old 01-15-2021, 11:33 AM
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Regular readers here, should have the "learned amount" of knowledge about which rockers to use and NOT to use!!!

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  #25  
Old 01-15-2021, 11:39 AM
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So seems everyone thinks there heads are good and everything else they make is junk?

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Old 01-15-2021, 11:42 AM
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Perfumed pig parts. Don’t use!

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Old 01-15-2021, 12:01 PM
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I have been watching all the post on there heads so far all has been good to very positive?

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Old 01-15-2021, 01:12 PM
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Well lets look at the numbers here again.

If your running whatever type of Cam , valve sizes and rpm that needs no more then 300 lbs of open pressure, then that gives you according to there info a 17% safety factor, so I don't know as they may live good long lives and never give a problem, or they may fail after a certain number of cycles.

After looking at Mgarblik's post where one failed and all the others where well on there way to going south I would not trust them even with 30% pressure of safety factor !!!!

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  #29  
Old 01-15-2021, 01:31 PM
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I feel sorry for people who buy this crap thinking shiny aluminum is better than stock. When it comes to engine parts, you really do get what you pay for, if you're lucky.

I see posts frequently in the Facebook groups from guys showing off their shiny new engine builds with crap, low quality rockers and I cringe every time. It's parts like these that chase people out of the hobby. Very few people can just keep throwing money at an expensive engine build to fix broken parts.

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Old 01-15-2021, 01:42 PM
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I’m just talking the heads not rockers like I said I don’t trust scorpion rockers.

  #31  
Old 01-15-2021, 03:02 PM
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Quote:
Originally Posted by Will View Post
I feel sorry for people who buy this crap thinking shiny aluminum is better than stock. When it comes to engine parts, you really do get what you pay for, if you're lucky.

I see posts frequently in the Facebook groups from guys showing off their shiny new engine builds with crap, low quality rockers and I cringe every time. It's parts like these that chase people out of the hobby. Very few people can just keep throwing money at an expensive engine build to fix broken parts.
What gets me is the same guy that spends piles of money on a shortblock...hours and hours figuring out cam selection..then chinks out on a few hundred dollars for good necessary parts.
What the average Joe doesnt know..is if someone bought a used set of Harland Sharps...you could send them into Harland Sharp for a "checkup" and possible rebuild and the cost is minimal and turn around is quick. Try that with an offshore rocker. Picture is an example of a 2 week turnaround and how I received them.
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  #32  
Old 01-15-2021, 03:38 PM
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As far as the heads go I haven't paid much attention to any chatter on them. If they are like anything that has been floating around the BBC and Ford world that I've seen, I'll pass.

Basically with anything like that I'd be sending them off to a competent machine shop to have everything checked over before I even think about bolting them on. A lot of cases with Chinese heads in the past with other make engines, most of the parts were tossed for better pieces, new guides, sometimes seats, and basically just the castings are used. I know everyone has a budget but ending up like this doesn't seem like you come out ahead much, unless you want to roll the dice and bolt them on out of the box and take your chances.. I just won't do that with any engine build.

Even with a name brand head I'd have everything checked, but the chances seem to be better that you'll use most of what the heads come out of the box with.

I'll stick with Eddy and KRE when it comes to basic Pontiac heads. If you want exotic and money isn't a problem there are other better options.

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  #33  
Old 01-16-2021, 10:41 AM
PontiacJim1959 PontiacJim1959 is offline
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Quote:
Originally Posted by mgarblik View Post
About 2 months ago, I had a 70 SS454 Chevelle towed to the shop with major engine damage. Engine had 2800 miles on a $7000.00 rebuild. Turns out the guy was super lucky. Chinese aluminum rocker arm failure. Axle pin worked out, broke the aluminum out of the tip end, dropped a valve, bent it like a pretzel, bent 2 push rods, shattered the valve guide, beat the hell out of the seat, sent metal fragments all around the one head. Fortunately, the engine was idling in a car show parking lot when it failed. I removed one head, rebuilt the head, put it back together along with a new set of Crower STEEL rocker arms. No major damage to the engine itself other than a few rat bites on the piston head, combustion chamber and intake port. Point of the post: Most of these Chinese rocker arms do NOT have a positive method for retaining the axle pin in the tip. They have a drilled clearance hole in one side and a tiny Knurled hole on the other end. The pin is inserted and a light press is applied to the pin to push it through the knurl in the aluminum. It's a ticking time bomb. There is no way the pins will stay put through millions of cycles. I inspected the rest of his rocker arms and 11 of the remaining 15 rocker arms had the pins moving out toward a similar fate. I know nothing about these Speedmaster rocker arms, but after looking them over, I couldn't find a single picture or text that mentioned how the pins are retained. There is no way I would use ANY aluminum rocker arm that doesn't have a positive retention method on the pin end. Jesel uses snap rings. Other less expensive designs swedge the pin on the outside. Pushing the pin through and hoping the termites hold it in there is non-starter for me.
Interesting points.

I saw Harland Sharp as a suggested rocker, but, from off their website, "Harland Sharp's pins are larger, offering increased strength, and knurled to eliminate spinning. "

Seems many knurl, some swedge, and I did not see any using snap rings on the tips other than the Jesel you mentioned. Jesel seems to offer the snap rings on the pin end, BUT, they also sell rockers without them and are press fit. So how bad can knurling, swedging, or press fit be depending on the intended use?

Reading specs on some of the roller tipped rockers, they too have a rating as to how much spring pressure can be gone up to. If I put Comp Cams roller tip rockers on a .700" lift roller cammed engine that spins 7,500 RPM's, would they hold up? Doubt it, wrong application for the engine in question. In doing a search on roller rocker arms in general, like all things, there are personal favorites and recommendations and the failure stories - to include the personal favorites and recommendations.

Interesting in reading all the responses when no one(?) here has one of the rockers in hand or has installed a set to evaluate. Has anyone of the tech guys here put the rocker arms through a rigorous evaluation to measure such things as alloy hardness, fatigue strength, cycle longevity, or any other lab test that can be factual and conclusive as to the quality and/or application of these rockers on an engine?

I am not endorsing or condemning the rockers as they may be perfect for some builds and a disaster for others. I am not looking to purchase a set either, just pointing these out as another Pontiac offering from Speedmaster being thrown into the pot of other manufacturing offerings. But, either lab testing or actual experience would be the concluding evidence in rating this product - and not rating it based on opinion - although my initial question does in essence call for opinion. Now if we could get some independent testing, or use with them, this would answer a lot of questions for everyone - me included.

  #34  
Old 01-16-2021, 11:05 AM
mgarblik mgarblik is offline
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I am sorry not to have been more clear in my post. Knurling the aluminum part of the rocker arm is not the problem in itself. I was not clear on that. If you are installing a hard steel pin in a soft aluminum rocker arm, you would rather not have the pin spin and wear out the aluminum. But once the pin is installed, do something to keep it in place. Snap ring, swedge, stake, something. Just pushing the pin in place and depending on luck to keep it there with the constant banging of the rocker on the valve tip and all the other harmonics vibrating through the valve train is asking for trouble. Some of the Jesel arms have a bronze wear bushing in the aluminum and the pin runs in them. Kind of like a full floating wrist pin. Of course, that's a very expensive method of making a rocker arm. When you combine cheaper materials, lower quality pins, marginal machining methods and loose tolerances, you get the pretty Chinese aluminum rocker arms with no functional benefits and allot of potential failure modes. At a rated spring pressure of 360 lbs. open, a stock stamped rocker arm would be just fine as long as the slot length was adequate for the valve lift. For a more performance oriented build, I much prefer the far superior cycle life of a steel roller style rocker arm. I have used the Crower and Comp. steel stud mounted stuff. Seem to work well with zero failures so far.

After re-reading PontiacJim 1959 post again, I need to add: The Speedmaster rocker arms in question may be just fine, and I did say no personal experience with them. ANY part offered for our ancient orphan engines has the potential to be a good thing and I would be the last to condemn them without real world testing. And I don't condemn them outright. If someone brought me a set, I would inspect carefully to see if any retention method is used on the pin. If not I would probably set at least one up in a mill vise and tap on the pin with a pin punch and see if it comes right out. I would also inspect the fit of the pivot to the bearing and the body and the overall finish of the pivot shaft.


Last edited by mgarblik; 01-16-2021 at 11:18 AM.
  #35  
Old 01-16-2021, 01:40 PM
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Quote:
Originally Posted by mgarblik View Post
I am sorry not to have been more clear in my post. Knurling the aluminum part of the rocker arm is not the problem in itself. I was not clear on that. If you are installing a hard steel pin in a soft aluminum rocker arm, you would rather not have the pin spin and wear out the aluminum. But once the pin is installed, do something to keep it in place. Snap ring, swedge, stake, something. Just pushing the pin in place and depending on luck to keep it there with the constant banging of the rocker on the valve tip and all the other harmonics vibrating through the valve train is asking for trouble. Some of the Jesel arms have a bronze wear bushing in the aluminum and the pin runs in them. Kind of like a full floating wrist pin. Of course, that's a very expensive method of making a rocker arm. When you combine cheaper materials, lower quality pins, marginal machining methods and loose tolerances, you get the pretty Chinese aluminum rocker arms with no functional benefits and allot of potential failure modes. At a rated spring pressure of 360 lbs. open, a stock stamped rocker arm would be just fine as long as the slot length was adequate for the valve lift. For a more performance oriented build, I much prefer the far superior cycle life of a steel roller style rocker arm. I have used the Crower and Comp. steel stud mounted stuff. Seem to work well with zero failures so far.

After re-reading PontiacJim 1959 post again, I need to add: The Speedmaster rocker arms in question may be just fine, and I did say no personal experience with them. ANY part offered for our ancient orphan engines has the potential to be a good thing and I would be the last to condemn them without real world testing. And I don't condemn them outright. If someone brought me a set, I would inspect carefully to see if any retention method is used on the pin. If not I would probably set at least one up in a mill vise and tap on the pin with a pin punch and see if it comes right out. I would also inspect the fit of the pivot to the bearing and the body and the overall finish of the pivot shaft.
All good points. I myself am good with the aftermarket stamped steel rocker arms and have used them - longer slot in the fulcrum area for higher lift cams without fear of binding, grooved rocker arm ball for better oiling, more consistent rocker arm ratio than stock, and of course, new. But, like all parts, have their limits depending on build - and bragging rights.

On my 455 build, I decided to try the Comp Cams roller tips "just because", not other reason. I have both the 1.5's and 1.65's figuring I can play a little with the lift. I could have gone with stamped steel I suppose. Crower cam calls for a spring rate of 115 closed & 290 open - .477"/.501" lift @ 1.5 ratio. Trying 1.65's should still keep spring pressures below what Comp recommends - 350 lbs open pressure. But, I won't know until I get the engine installed and out on the road.

I can't see using an aluminum body roller rocker on a street engine. Aluminum fatigues over time and how may actually pull apart their street engine valve train to inspect? Most owners are drivers, not mechanics. BUT, if I did go roller rockers, then the Stainless Steel would be the only choice for me whether I had a big lift roller cam turning high RPM's or a more factory type build. And of course, I personally feel that many of the horror stories are because people buy products, believe they can just slap them on, and never inspect for clearance issues - and then something binds or hits and Bam, broken parts or worse. I think many of us have added parts in our youth that should have been clearanced or checked and we did not - like installing a big lift/duration cam to gain 40 more HP in our stock engine and never taking into consideration the valve springs should have been upgraded, long slot rocker arms were needed, and retainer to valve guide clearance should be checked. Many of us got lucky, some got broken parts and just wrote it off as it was just an old engine anyway and I can put another one in (remember the supply of $100 junk yard engines? LOL).

I like the Jesel idea of the longer roller tip pins & retaining locks. I'd like to see that on all roller tips just for insurance purposes and peace of mind. But, you have to have faith in that the engineers who design these parts know what they are doing and take into account things like thermal expansion when creating an interference fit in pressing in the roller tip pin. I would like to see, and feel more comfortable, with a test done on the Speedmaster roller tip pins in finding out how much force is needed to press those pins out at room temperature and then at the higher running temps a race engine can see. I'd like to see destructive testing, at what rated PSI does the rocker arm break? How about Brinell/Rockwell hardness testing of the aluminum body and the steel needle bearings? I would also want an independent US laboratory do the testing for impartial results.

So these rockers may be a great deal for some, but I would want to know more about the design parameters, metallurgy, and stress/cycle testing under minimum/maximum extremes. Field testing and waiting for peer reviews seems dicey and makes me hesitant in trying these when Pontiac engine builds are not inexpensive and some of us could not afford to lose a $6,000 and up engine and simply slap together another and call it a learning experience.

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