Magnum Roller Lifters

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360duster said:
ok, who´s got more.....;-)))

.620" Lift, no trouble at all. As said before 6900 -7000 rpm trough the traps.

Michael
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Damn son, what's the rest of your valvetrain setup? I thought hyd rollers got unstable after about 6400 RPM...
 
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I've got some Harland Sharp roller rockers that won't break and solid lifters for the LA or magnum blocks if needed.
 
Killer6 said:
Any collateral damage from that failure? Plus a bit of debris searching, at least You kicked up some useful info here anyhow.
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hadnt really dug into the engine yet. the broken piece is MIA so im hoping it didnt fall in with my cam. Around the stud area I was seeing metal dust/chips so im gunna have to tear it down and clean. im just hoping nothing else is damaged. Definately wouldnt recommend those for anything.
 
mopowers said:
Thank you for the update.
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I kinda feel bad about blaming the lifter. when I took the valve cover off I played with the lifters and that one had a lot of play so thats what I figured it was. Last night I actually took off my Rocker girdle as well and thats when I could see the rocker was cocked. Then I felt around and then noticed the sharp edge.
 
Jonnylightening said:
I kinda feel bad about blaming the lifter. when I took the valve cover off I played with the lifters and that one had a lot of play so thats what I figured it was. Last night I actually took off my Rocker girdle as well and thats when I could see the rocker was cocked. Then I felt around and then noticed the sharp edge.
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Don't feel bad at all. At least you had the nuts to show us all what the problem was. Too many people start threads like this and don't ever report back. Hopefully you can get it all buttoned up and get it going again.
 
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mopowers said:
Don't feel bad at all. At least you had the nuts to show us all what what the problem was. Too many people start threads like this and don't ever report back. Hopefully you can get it all buttoned up and get it going again.
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Big thing now is which rockers to go with this time around?
 
You may be able to get small block Chevy rockers cheaper. Not saying cheap is good, but if you can get higher quality rockers for SBC cheaper....why not? I know several people who have used the SBC roller rockers on Magnum heads with good results. Maybe do a little research on the SBC rocker swap before plunking down mo money. Hopefully, the pieces of that busted rocker that are MIA got by the cam without causing any damage.
 
Jonnylightening said:
Any company out there that make an actual quality lifter anymore? I have had a set of brand name hyd. roller lifters in my car for 2 years and yesterday during a car cruise one desired to give up on me 2hrs away from home. These were supposed to be “performance” lifters. I’m kind of over the whole hydraulic thing. Can anyone point me in the direction of a solid roller for magnum blocks?
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Any id
ea what caused it to collapse. Possibly something got in the valve in the lifter that lets it bleed down rapidly. You would think that with 8k miles on it any crap would have come out long ago, but crazy crap happens. A bit of casting flash or sand, or a drill burr finally broke off.
 
Bobzilla said:
Check some of the remaining rocker arms to make sure they are not binding on the poly locks at full lift or when closed with the pushrods you currently have.
Also, can you post a picture or two of the other rocker arms on the engine. Curious how they look.
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my heads were gone over by a reputable guy...there again not mentioning names. absolutely no binding whatsoever. everything was checked and gone over before they key was even turned the first time. Same rockers were in the engine for the 3 years ive had it now. Rockers I was sold from him were I believe procomp or PRW? (Chinese rebranded)
 
Jonnylightening said:
my heads were gone over by a reputable guy...there again not mentioning names. absolutely no binding whatsoever. everything was checked and gone over before they key was even turned the first time. Same rockers were in the engine for the 3 years ive had it now. Rockers I was sold from him were I believe procomp or PRW? (Chinese rebranded)
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my car is currently at my buddies shop an hour away from me so soon as I get down there ill get more pictures and ill get the actual brand of rockers. They broke across the casting line. its not a straight clean break as you can see from the pick but it starts at the front of the casting line and ends at the back of the casting line. With the way the world is now it seems like almost everything you buy is **** quality.
 
[1] Doubt a Chebby rocker will work; the SBM rockers are very short.
[2] A lifter could still have caused this; if it pumped up, the posi lock or the stud may have made contact with the rocker body.
[3] Harland & Sharp rockers will break just like any other rocker if overloaded or faulty [ post #29 ]
[4] Check the underside of the rockers for contact between the stud & rocker slot, at full lift.
 
Jonnylightening said:
my heads were gone over by a reputable guy...there again not mentioning names. absolutely no binding whatsoever. everything was checked and gone over before they key was even turned the first time. Same rockers were in the engine for the 3 years ive had it now. Rockers I was sold from him were I believe procomp or PRW? (Chinese rebranded)
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Completely understand, and no judgment here. Actually wondering if something has changed or moved since it was originally assembled. The picture you posted does not appear to show signs of binding until after the breakage occurred, so maybe just that rocker arm gave up after many cycles. Figured they were PRW and they are usually pretty reliable on this type of build.
 
Harland Sharp.
I ran them on a set of stage 3 ported magnum cast iron 2.02 R/T heads just fine. 1.7:1 and 1.6:1 at different times with no issues, and I beat on this engine all the time very often seeing 7k rpm for years. Sold it and it's still going as far as I know.
 
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