CAM worn lobe??

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Originally Posted by nativetalon

I'm not sure what you mean, and if so, how do i fix it?

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These engines don't have adjustable valvetrains from the factory,,,meaning the rocker arms are torqued to spec and that's it. The lifter preload and valvetrain geometry is set by the pushrod length.

You mentioned you installed new rockers, but didn't mention if you converted to adjustable or not. There are many kits out there that allow adjustability so you can set preload to a desired amount.

I don't remember if you mentioned replacing push rods either. The standard length seems to be in the 7.4" area, but I've been hearing that alot of shops are going just a tad longer now on the "NON" adjustable setups to quiet the lifter noise down a bit.

Not to mention also,,,,larger camshafts generally are ground with a smaller base circle (that's how the lift is obtained) which in most cases requires a longer pushrod anyway to get valvetrain geometry back in check,,,and also set proper preload on the lifters if your valvetrain is "NON" adjustable.

how would i know the difference? and i bought comp cams ultra gold rockers and also 7.4 pushrods. how will i know if i need longer pushrods, and how do i measure to assure proper lenght?

and also, cam lift is 601/612

Quote:

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Originally Posted by nativetalon

how would i know the difference? and i bought comp cams ultra gold rockers and also 7.4 pushrods. how will i know if i need longer pushrods, and how do i measure to assure proper lenght?

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Hmmm, I'm looking at the comp cam website. There is no mention of whether or not the the ultra gold rockers for the LS engines are adjustable or not. They only say they are stud mounted. So I can only guess.

I run stud mounted Crane roller rockers and they are fully adjustable. There are others out there that stud mount,,,but are not adjustable and basically mount onto a stud that is bevelled. Much like a conventional pontiac engine similar to what your 79 firebird in your picture would have.

I'm taking it that you didn't install the parts? You would have either simply torqued the rockers down to spec and let it be, as preload is set by pushrod length. Or you would have had to adjust lifter preload with each individual rocker. Setting lash just as you would on an older GEN 1 SBC.

no i paid Larry Turner's Performance $850 to do the work with $4000 in parts and the 1st time i got it home it sounded ok when i left the garage about 30 miles away. but it was ticking by the time i got home. and finally started to sound like a rocker was coming aloose so he then come bak amd got it. then again when i drove it home it started the same ticking and it has been parked since last march. o haven't had the cash to find out what it is until now. so this time I'm going to try to do the work myself. what do you suggest? different rockers?