if the cam was being held forward by the plug it could have contributed to the lobe wear
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A few of the failures look at the exhaust valves then see if its weird the dont have the same heat spots.
And you can see how far my cam tunnel plug was pushed in.
And you can see how far my cam tunnel plug was pushed in.
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And here are a few more of 1 lifter about to go plus wear on the distributor gear that Looks a little intense to me.
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This has nothing to do with it being a flat tappet (even "in this day and age") or the break-in. This was strictly an assembly error; the cam moved one way or the other, some of the lifters contacted the lobe next door taking the edge of the lifter off, once that happens it's game over. Edge loading is the quickest way to fail a cam.
The cam plug is in too far. Is it far enough to cause a problem? It could be or it might not be, often times it will have some brown/blue heat marks on it from the rubbing, but this may not have run long enough for that to show. It could also be that the cam moved back too far if the timing chain set up used a thrust bearing/bushing and it did not get installed. Yes, believe it or not, I have seen this. A good friend made that mistake somehow and we caught it on the dyno. In this case, the new tight chain kept the alignment decent enough for the engine to run ok - though I did notice a bit more spark scatter than I like to see - but it was a warmed over stock 383 with no trick parts so no one got too excited. But as time went on there were some misfires at high speed and the timing scatter got much worse so we took a good look and while the distributor was being checked out I had a look into the valley (Mopar RB dist hole is huge) and found the issue. Attached are a few pics for you.
In your pics I can't tell which is the front of the block, that will tell you which way the cam moved too far. In any case, you should run a cam button and set end play before putting the cam plug in and the plug goes in just flush. It also looks like yours was hitting the sides of the lobe and the rough cast radius took the edge off.
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The cam plug is in too far. Is it far enough to cause a problem? It could be or it might not be, often times it will have some brown/blue heat marks on it from the rubbing, but this may not have run long enough for that to show. It could also be that the cam moved back too far if the timing chain set up used a thrust bearing/bushing and it did not get installed. Yes, believe it or not, I have seen this. A good friend made that mistake somehow and we caught it on the dyno. In this case, the new tight chain kept the alignment decent enough for the engine to run ok - though I did notice a bit more spark scatter than I like to see - but it was a warmed over stock 383 with no trick parts so no one got too excited. But as time went on there were some misfires at high speed and the timing scatter got much worse so we took a good look and while the distributor was being checked out I had a look into the valley (Mopar RB dist hole is huge) and found the issue. Attached are a few pics for you.
In your pics I can't tell which is the front of the block, that will tell you which way the cam moved too far. In any case, you should run a cam button and set end play before putting the cam plug in and the plug goes in just flush. It also looks like yours was hitting the sides of the lobe and the rough cast radius took the edge off.
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