Pro Magnum Lifter Question
Thread Starter
Drifting
Joined: Jun 2002
Posts: 1,340
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From: hamilton nj "Life's tough......It's even tougher if you're stupid."-John Wayne
Pro Magnum Lifter Question
Any truth to the rumor that when using Pro Magnum Lifters from Comp Cam that you need to use adjustable rockers? 
Pro
Joined: Mar 2004
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Originally Posted by Face
Nope. You have to make sure the pre-load is dead on though.
I'm not a huge fan of their new design. I had one fail on me after a track day at Pocono in my old L98 engine, found the steel plunger retainer plate in two pieces stuck to my oil drain magnet. No other indications of the failure, engine ran fine, just happened to be doing an oil change afterward. I noticed on ls1tech.com that I'm not the only one this has happened to. Preload was zero lash + 1/8 turn on the adjustable rockers.
So...either there's a flaw, or they're super duper sensitive to preload and somehow a slight misadjustment can make that little retainer fail.
Either way, I'd either stick with stock lifters or go with Morel ones that aren't picky about preload. Do a search on ls1tech.com internal engine forum for morel and you'll see what I'm talking about.
Thread Starter
Drifting
Joined: Jun 2002
Posts: 1,340
Likes: 1
From: hamilton nj "Life's tough......It's even tougher if you're stupid."-John Wayne
Originally Posted by crainholio
...and the easy way to get the preload dead on is w/ adjustable rockers.
I'm not a huge fan of their new design. I had one fail on me after a track day at Pocono in my old L98 engine, found the steel plunger retainer plate in two pieces stuck to my oil drain magnet. No other indications of the failure, engine ran fine, just happened to be doing an oil change afterward. I noticed on ls1tech.com that I'm not the only one this has happened to. Preload was zero lash + 1/8 turn on the adjustable rockers.
So...either there's a flaw, or they're super duper sensitive to preload and somehow a slight misadjustment can make that little retainer fail.
Either way, I'd either stick with stock lifters or go with Morel ones that aren't picky about preload. Do a search on ls1tech.com internal engine forum for morel and you'll see what I'm talking about.
I'm not a huge fan of their new design. I had one fail on me after a track day at Pocono in my old L98 engine, found the steel plunger retainer plate in two pieces stuck to my oil drain magnet. No other indications of the failure, engine ran fine, just happened to be doing an oil change afterward. I noticed on ls1tech.com that I'm not the only one this has happened to. Preload was zero lash + 1/8 turn on the adjustable rockers.
So...either there's a flaw, or they're super duper sensitive to preload and somehow a slight misadjustment can make that little retainer fail.
Either way, I'd either stick with stock lifters or go with Morel ones that aren't picky about preload. Do a search on ls1tech.com internal engine forum for morel and you'll see what I'm talking about.
Thanks, I think I'll sell them and go with another style!!
Melting Slicks
Joined: Mar 2003
Posts: 3,116
Likes: 10
From: Macomb MI
Originally Posted by budmont
Thanks, I think I'll sell them and go with another style!!
I am pulling mine out wh en I go back into it..they are a pain in the *** and not worth the box they cam in..
Solid rollers would have been less maintainance.
Phil
