What are the practical limits to the stock Magnum Rocker package?

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71dusterdan

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Hey guys gonna start building my engine soon. I know the stock La rockers are pretty good, they may not be accurate enough for some of the hardcore, but they can be plenty stout and reliable! Had them in a 360 years ago with a .509 lift cam and spun it to 6000 rpm all the time, with no problems! My question is how far can I push the stock Magnum rockers in a similiar package. Hughes has spec'ed thier 2228 hydraulic roller cam to me, for my La block/eq magnum head combo. The lift with a 1.6 rocker is .544. Assuming the mods made to the spring seats, and the proper springs, will my stock magnum rockers hold-up? This is going to be a daily driver, with 10-1 ish comp(flat-tops and mag chambers), hi-po exhaust manifolds, performer intake, and TQ carb, with a recurved stock ignition. Thank you. Dan:banghead:
 
I'm assuming so because their whiplash cam for a 360 is around the same lift and its "supposed" to before otherwise stock heads.
 
What is the spring pressures on the required springs? I'd think you'd be fine, but the issue is more of "over time".
 
Ive been running the stockers on my EQ magnum heads since 09. Lots of 11 second passes and 6300 RPM or a little more. No issues with them so far.

Switching to roller to free up a little horsepower and get some under valve cover bling-LOL

My cam is 22x/23x duration .536/.544. lift I am running the hughes 1110 spring. It works. If I had it to do over again, I would have had the spring seats cut before I ordered them. I'd really like to run a beehive, but there isn't anything available with the stock installed height that works with .544 lift.

Be sure to check your pushrod length. Even with a skinnier than stock head gasket, mine required a .050 longer pushrod. The roller rockers might need a longer one still....
 
I ran stock rockers and pushrods in a 360 magnum circle track car. I had a hughes hyd roller .580ish lift, and 2.2 Litre retainers with the Mopar performance valve springs. I would have valve train issues if I spun it up past 6000 rpm. Likely pushrod flex would take the rocker and pushrod out. Keeping it inder 6000rpm everything was good
 
Ive been wondering the same thing. I am doing a magnum head swap and with my cam (voodoo 268) and 1.6 rockers, exhaust lift will be .548! The guildes have been cut down and It seems I have enough spring clearence, but not sure how much the stock magnum valvetrain can handle. I dont plan on spinning it past 6000. Ive been lookinga at replacing the voodoo with an oldschool comp 280 magnum that would put the lift at .512 which I feel is safer, but would really like the voodoo cam if I can make it work.
 
Thanks guys...I really have been thinking about that cam. I'm not sure it is in my best interests...I am not looking for all out max hp, but rather near OE reliability and daily driver capable. Hell didnt the 380 horse magnum crate use a 509 cam? I guess the roller just gives you so much more capability for lift, the engine guys feel you have to use it. So I am still unclear...will the heads need much work on the spring seats and guides to run a cam that big and the appropriate springs?
 
I have stock magnum rockers on my 360 with a .525 lift cam and 125# seat and 310# at .550 lift springs. I found that it bends valves at 7200rpm but since then I shift around 6000 and have not ever had a problem since. :)
 
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