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So this is not on my Corvette but on my Chevy truck that is my daily driver. Everyone is always such a help here I thought I would post this and get everyone's thoughts. I am changing the cam on the 350 as I suspected some flat lobs, but upon taking it apart discovered that there are 5 different rockers that the tips of the rockers are severely warn, some were on the valve tip, groves on the rocker studs and the corresponding cam lobs are warn, but not quite flat.
The cam is little only 204/214 at .050 and around .440 lift, the heads are world product S/R toquer heads and the valve springs are the ones for the cam. The Cam, lifters, springs and rockers have about 40,000 miles on them and the heads around 80,000 miles on them. I drive 80 miles a day on the high way at 2100 rpm. Spent all my money on my Corvette so I need to figer a way to make this work with the least amount of money.
So this is not on my Corvette but on my Chevy truck that is my daily driver. Everyone is always such a help here I thought I would post this and get everyone's thoughts. I am changing the cam on the 350 as I suspected some flat lobs, but upon taking it apart discovered that there are 5 different rockers that the tips of the rockers are severely warn, some were on the valve tip, groves on the rocker studs and the corresponding cam lobs are warn, but not quite flat.
The cam is little only 204/214 at .050 and around .440 lift, the heads are world product S/R toquer heads and the valve springs are the ones for the cam. The Cam, lifters, springs and rockers have about 40,000 miles on them and the heads around 80,000 miles on them. I drive 80 miles a day on the high way at 2100 rpm. Spent all my money on my Corvette so I need to figer a way to make this work with the least amount of money.
Do the chewed up push rods correspond with the flat lobes? If so it makes you wonder if the the rocker arm nuts or the studs came loose causing a hammering effect wiping the lobes or if the lobe started to wipe causing the loose rockers and the hammering effect. The push rods were deffinently hammering as were the rocker arms and with the cam specs you would have thought that the cam was less prone to wiping due to low lift. If your going to repace, check out a retro roller, I know that you're on a budget and all, but you can reuse the lifters on the next rebuild.
DO MA NEU!
Last edited by bluedawg; Dec 1, 2014 at 02:09 PM.
Reason: My Wife caught me shagging my secretary!
FWIW, in the most recent issue of 'Chevy High Performance' magazine, there is a section with a number of "tech tips". One of these tips talk about out of round rocker studs. You might want to look into this....
Correction!
I subscribe to both 'Car Craft" as well as 'Chevy High Performance' magazines, and they both arrived the same day last week. The article I was referring to was actually in 'Car Craft'..........
Last edited by leadfoot4; Dec 3, 2014 at 07:54 AM.
Looks to me like the guide plates weren't set up properly and the rockers were offset on the valve stems. The wear on the rockerarm is offset too. If it was cocked off like this, that could explain the wear on the rocker studs as well.....just my guess.
I'd ditch the guideplates, get some cheap guided replacement rocker arms, replace the studs, and replace the valves that are worn.
How much RPM did this engine see? Is it possible you have been floating the valves?
Looks to me like the guide plates weren't set up properly and the rockers were offset on the valve stems. The wear on the rockerarm is offset too. If it was cocked off like this, that could explain the wear on the rocker studs as well.....just my guess.
Valve train problems
