What do you think about this statement.........

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Brooks James

Brooks James

VET, CPT, Huey Medevac Pilot
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On magnumswap.com, they claim that they " have spun stock magnum rockers to 6500 rpm regularly without failure"

Anyone been doing that ??

its becoming more and more apparent that in bone BONE STOCK form the magnum is superior to the LA
 
Brooks James said:
On magnumswap.com, they claim that they " have spun stock magnum rockers to 6500 rpm regularly without failure"

Anyone been doing that ??

its becoming more and more apparent that in bone BONE STOCK form the magnum is superior to the LA
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One of the reasons I run a Gen 3 hemi in my drag car is that the stock rocker stuff goes to 7400 rpm with no issues. Just have to use stiffer springs. I shift at 7000 since 2014 and have had zero issues. I replace springs every 2 seasons.
 
I've spun stock magnum rockers past 6500 rpms with Hughes spring kit. Not on a regular basis, by accident. I've not had a stock magnum rocker fail. Neither have I had a stock LA rocker fail, and I've gone past 6500 rpms with them also. I don't run a lot of spring pressure with stock stamp steel rockers.
 
Lol, my magnum engines won't spin over 5500 before the computer say knock it off.
I had a Dakota 5.2 short box regular cab back in 1997 that I ran top speed /redline for over 200 miles without lifting except to fill up with gas lol.
I've never seen a problem with those rockers but much rather have shaft mounts.
 
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In our Stock Eliminator Dakota, we twisted it 6000 to 6400 most of the time in first and second gear with no failures.
 
I can see it happenin with stock or slightly elevated spring pressures. I sure wouldn't do it with any moderate spring, though. Those rocker bolts are only 5/16".
 
Brooks James said:
On magnumswap.com, they claim that they " have spun stock magnum rockers to 6500 rpm regularly without failure"

Anyone been doing that ??

its becoming more and more apparent that in bone BONE STOCK form the magnum is superior to the LA
Click to expand...

6500 isn’t that much RPM.

For who for what? Just because you can doesn’t mean you should.

There isn’t a damn thing “superior” about a junky stud mounted rocker. Nothing.
 
OEM Magnum rockers are NOT stud mounted, it is actually metric bolts that attach them to the head.
 
Demonracer said:
OEM Magnum rockers are NOT stud mounted, it is actually metric bolts that attach them to the head.
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8 bolts holding down 8 rockers or 5 bolts holding down a shaft and 8 rockers. I bet the engineers did their homework.
 
toolmanmike said:
8 bolts holding down 8 rockers or 5 bolts holding down a shaft and 8 rockers. I bet the engineers did their homework.
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The engineers did their homework for an engine with crap (90 on the seat) for spring pressure, and makes peak torque at 3800-3900 rpm and runs out of intake manifold and head before 5500. Stock magnums are truck engines that were never designed to operate anywhere near 6500. That being said, I’ve turned my 5.9 with 550lbs over the nose and cheap Chevy 1.5 roller rockers to 6700 more than a few times in my younger days. The stock stuff does hold up pretty well to (like said above) moderate spring pressure and rpm. But get a serious spring and an aggressive lobe in there and watch for snapped rocker bolts.
 
Also, instead of using stock bolts to hold the rockers down, larger diameter studs can be installed for greater spring pressure/rpm. Harland Sharp makes nice roller rockers as well. But I think the point is in most cases, if there is a serious HP build, aftermarket heads will be used anyways.
 
Newbomb Turk said:
6500 isn’t that much RPM.

For who for what? Just because you can doesn’t mean you should.

There isn’t a damn thing “superior” about a junky stud mounted rocker. Nothing.
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The only time I've had stockish engine spin
Past 6500 was an L79 chev 327/350 hp motor that I put a solid lifter Sig Erson Cam in. I spun that to 7500 a couple of times
 
toolmanmike said:
8 bolts holding down 8 rockers or 5 bolts holding down a shaft and 8 rockers. I bet the engineers did their homework.
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I wish it was that simple, but it’s not. This has been argued to death for decades. The answer is no one builds any kind of power with ball/stud or bolt down rockers. Not even the GM guys who swore for decades the ball/stud rocker was superior.
 
Newbomb Turk said:
I wish it was that simple, but it’s not. This has been argued to death for decades. The answer is no one builds any kind of power with ball/stud or bolt down rockers. Not even the GM guys who swore for decades the ball/stud rocker was superior.
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I agree there. The chevy boys have been modifying for shafts and girdles and the like to make their junk strong enough to live with big springs and at healthy rpm. Mopar can probably get the job done with stock shafts and factory iron rockers.



chevy head.jpg
 
Magnum pedestal mount rockers are basically a direct copy of Ford's small block. There isn't anything superior, they work for sure.
The magnum heads were basically junk time bombs from the factory ( thanks ma Mopar)
Shorter deck blocks (why)
Metric bolts (why) nothing wrong with them but were in the USA buddy lol.
As a fuel injected stock in truck or van they were computer controlled and took Mopar performance expensive computer or buy a tuner.
Instead Ford and Chevy were using mass air flow sensor which you could make power easier.
I think the magnum is crap stock but it was durable until many of their problems showed up
 
Newbomb Turk said:
I wish it was that simple, but it’s not. This has been argued to death for decades. The answer is no one builds any kind of power with ball/stud or bolt down rockers. Not even the GM guys who swore for decades the ball/stud rocker was superior.
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Except the dorks who put LS rockers on Mopar small block heads... where's the emoji for shaking my head
 
To the OP, I'm not debating if fulcrum mount or shaft mount is better. So, that being said, I did a dirt engine for a local racer that ran a B-mod for a couple seasons. 9 to 1, two barrel deal. Ran the Hughes race hydraulic, flat tappet lifters. Figured appropriate preload for the lifters. He ran that to 6200 regularly.
 
MOPARMAGA said:
What part of the magnum was superior stock???
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Better metallurgy in the blocks (nickel content) supposedly, better machining, higher compression ratio (stock vs stock) and fuel injection kept them from wearing rapidly. The stock pistons in a magnum are hypereutectic and the stock rods and crank hold up well to a serious beating. All good things for a “cam, heads, and intake” type build.

Edited to add;
Roller cams from the factory. Much easier to upgrade.
 
TT5.9mag said:
Better metallurgy in the blocks (nickel content) supposedly, better machining, higher compression ratio (stock vs stock) and fuel injection kept them from wearing rapidly. The stock pistons in a magnum are hypereutectic and the stock rods and crank hold up well to a serious beating. All good things for a “cam, heads, and intake” type build.
Click to expand...
Crap I gave away all my extra magnum hard parts.
 
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