Quick question I have 1600 miles on my 402 BB which was rebuilt and just a smidge above stock and it seems one of my rockers walked and got lose? I have a new roller cam which has about a 509 lift. I am using roller rockers with the nuts that come with them (they are like the stock nuts). I have experienced this in the past is this common for chevy engin
402 Engine Rockers
Agugliel72SS
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Quick question I have 1600 miles on my 402 BB which was rebuilt and just a smidge above stock and it seems one of my rockers walked and got lose? I have a new roller cam which has about a 509 lift. I am using roller rockers with the nuts that come with them (they are like the stock nuts). I have experienced this in the past is this common for chevy engin
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5,100 Posts
Poly locks are good. I can't stand factory rocker nuts.
Not familiar with BBC heads. Are they screw in studs or press in? Could it be loose or pulling out?
ARP Rocker Arm Nuts - Polylock Rocker Arm Nut Style - Free Shipping on Orders Over $99 at Summit Racing
Not familiar with BBC heads. Are they screw in studs or press in? Could it be loose or pulling out?
ARP Rocker Arm Nuts - Polylock Rocker Arm Nut Style - Free Shipping on Orders Over $99 at Summit Racing
1970 El Camino SS396, VortecPro 467, ATI TH400, Moser 12 bolt /TruTrac 3:42, Hedman headers
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1,682 Posts
Polylocks if your valve covers will tolerate the additional height OR Mark Jones had a neat solution with an added 7/16’s fine threaded nut under the adjusting nut...FWIW.
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I have stock valve covers basically a stock engine and as for the fine thread that is a good idea.
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The stock stover nuts can get loose, but also a rocker stud that does not have a flat top will prevent a poly lock from setting tight .
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Not crazy for the factory 7/16 bolts and when used a few times they can tend to lose grip! I believe they are screw in I cannot recall I am taking off the cover tonight.
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Thank you every went through all my bolts I unfortunately I reused the Comp Cam acorn bolts when I bought them back in 2000 and they were taken off and on a couple of times which most likely weakened the threads.
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281 Posts
Here is an update took off the driver side valve cover and found the issue with the loose rocker which was a bit loose and caught in time. Spent some time reviewing all the rockers and looking at the springs all looks good and same with what I can see int he valley on some of the lifters. I plan to change all the bolts for the rockers. It is the last photo that is the rocker arm that was loose.
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1968 Malibu Sport Coupe, 489c.i. 590hp 600tq, TCI 200r4 Freakshow 3,600 stall, 3.73 12 bolt posi
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15,653 Posts
Get a new set of stock type nuts or short poly locks if you have the room
When you shut your engine off and the hydraulic lifters bleed down, it's not uncommon for a few to appear loose, depending on that valve's location with respect to it's cam lobe. Or stated another way, it's possible you don't have a problem. Did you have noise from the valve train?
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That is the plan with the stock nuts and I will try for poly locks.
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I agree and I wish there is one that is completely off so basically with cranking the motor in small increments only one so far is off.
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Great thank you replaced them, and the engine is fine will monitor just a freak thing and these issues happen!
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They do work fine once they’re set. I also used the pioneer nuts. And like bill said, they should be replaced after use.
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