I would look into the spring pressure being too excessive for your cam. I have 120lbs of seat pressure for my comp cam and I had no problems with it. I used 10-30w oil with a pack of the supplied moly lube.
After reading HotRod's article on this subject, I have to ask these questions. Did you remove the inner valve springs before the break-in run? And what cam was it? The article somewhat comes to the conclusion I have as well, plus another factor I hadn't thought of, the ramp rate increase with the more agressive profiles now (but the two failures I had were older grinds) They generalized it into a combination fo things: Bad lifters, the reduction of zinc, plus a little bit of the lifters not spinning at fireup (the cam companies have improved the Parkerizing over what it was before) and the increased ramp and resulting spring rates. There was also mention of lifter bore problems too. But they ignored the improved friction reduction in today's oils, that has also got something to do with the lifters getting spun by the cam lobes.
D. and 68 coupe....good info. with respect to spring pressure, I fairly certain the spring pressure is 130 lbs on my Jegs heads, I 'll have to re-check that, but remember, I used those same heads with a Lunati cam and lifters and had no issues. The Comp was a new grind and the ramp increases may have been a problem, but I feel that if that could have been an issue that Comp should have made sure that I understood that possibility by including some additional info in their install instructions. If adding Rotella oil had been a good idea, that should have been included. If removing the inner spring was a good idea, that should have been included in Comps instructions. Reading it in Hot Rod Magazine is not the same as including that type of info in the install instrcutions provided by the manufacturer.
BTW, I completely disassembled the engine last night ...and the oil pan, all engine components etc. are covered with with very fine dark grey metalic residue. The pistons were new and the skirts show wear that should not be there for a 20-30 minute engine. The main and rod bearings looked 10 times worse than the bearings in the 800 mile engine I have sitting in the corner. The pistons in the 800 mile engine look new. The crank bearing surfaces, both rod and main appear 'stained", not really damaged necessarily but will need at least polishing before reuse. The engine is full of the finite remains of the cam/lifters. Cylinder walls look OK. The engine had a new HV Melling oil pump. My plan is to use the crank, rods and maybe the pistons from this 302 in the 289 block that has the 800 miles on it. thanks again for the reponses.
I found your problem. The inner spring is what got you, If you are running a cam that is large enough to have the inner spring, then its a must that you remove the inner spring and install them only after the cam is broken in. If you run a cam that has less than 525 lift or 290 advertised duration, toss the inner spring, I promise you dont need it, I also bet the comp cam was bigger than the lunati, which in turn used more spring pressure at max lift the comp could have had as much as 100# morespring pressure than the lunati, dont trash the block, I have seen some really damaged appearing lifter bores, just try the emory cloth to clean one hole. My lifter bores looked very bad, after cleaning them good I install a lifter to make sure it moved freely up an down and would rotate in the bore. It was my only option as I had just spent 600 on block work. It still works fine today. If the block has that much damage, then I definetly would go have the crank checked again polished as I have said before these are the parts I would worry about.
fast4cheap...you're exactly right on all the cam specs. the Comp was more lift and a little more duration. I have heard about removal of the inner spring before, but again, the instructions don;t address that, and I told the comp guy when I ordered the cam about the heads and spring pressures and he indicated that would not be a problem. I'm sure I bear some responsibility here, but not based on their install instructions!
I'll check the lifter bores as you stated and maybe they'll clean up, but man is that block full of fine metalic particles. The whole situation just really sucks.
Sorry to hear about all your bad luck, Hope you get everything straightened out, remember your not the first, and wont be the last, They should have told you to remove the inner spring most dual spring set ups have around 125-130# seat pressure which is way to much for break in. It was probally a extreme energy cam, which have agressive lobe profiles to begine with, let me know if your block cleans up, I think it will I seen some bad ones before. Good luck !
I meant to mention if the lifter bores do clean up just take out the oil gallet plugs and pay a visit to your car wash to remove those metal particals.
Also when you put the new cam in did you check the pushrod length? This is necessary when a cam is swapped. As stated earlier take out the inner springs to break in the cam. You will need to put them back in especially using a xe series cam. Look to see what the cam requires and check to ensure that your springs are that pressure. If too little spring pressure, the cam will float the valves at earlier high rpms.