Loud tap

Tech tips and how to's

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Gregs672000
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Re: Loud tap

Post by Gregs672000 »

Ugly! Dave is right, they are not wiping proper on the rocker. You can move the wipe pattern with thicker lash pads, however I don't recall which direction a thicker pad will move the pattern. Regardless, since they all appear to have been wiping about the same, it may be a good idea to go through the process of checking at least one intake and one exhaust rocker to see how the cam is riding on the rocker. Its not a difficult process... need to fully loosen the lash adjustment, remove the rocker, wipe it and the cam lobe clean of oil, use a sharpie pen to color over the pad surface, carefully reinstall the rocker, adjust the lash up some (visually look, don't use a feeler gauge, doesn't have to be spec but have it close-ish), spin the engine over a time or two, remove the rocker and look at the wipe. Should be close to the middle with equal or nearly equal unwiped sharpie still on the pad on each end. If not and it's a lot, or if it is clearly different from what pattern was already bedded into the cam and rocker previously, I might be concerned... just sayin.

With the cost of rockers and cams these days, it does not take long to damage/ruin a good cam or rocker arms, and you may be using this cam etc on your new motor. Checking now might give some peace of mind for your driving now, and in the future. I do understand the frustration of being in the driving season and missing out... I missed all of July and most of August this year with a broken wrist pin...
Greg Burrows
'67 2000 #588
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JackAuffeltrades
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Re: Loud tap

Post by JackAuffeltrades »

Thanks for the suggestion. I hadn't heard about the sharpie idea. I was just going to see if I could see the pattern today after it's been run for a few miles. And thanks for your write up when you had similar issues. I went through that thread while looking for guidance last week. That was nasty but I'm glad you found the problem. And you guys are right. Rockers, cams and core charges can add up quickly if things get too far gone. I'll keep an eye on it and try to dial them in.
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spyder
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Re: Loud tap

Post by spyder »

Those followers look like the single piece chrome faced. Toast, and the cam is likely damaged.
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Gregs672000
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Re: Loud tap

Post by Gregs672000 »

Yes, it's very hard to see the pattern with it assembled. It looks like it is close to the end but when you do the sharpie (can also use grease) it makes it clear. I use stock lash caps with my reground Racer Brown cam (technically stock 120 L-series caps in the modified head) but it requires thicker 160 caps for the reground Isky to wipe properly and both were cut from unground A cams.
Greg Burrows
'67 2000 #588
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redroadster
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Re: Loud tap

Post by redroadster »

Also could be from someone starting it dry reving high before it oiled up then wore more
,why the 1 plug wire start up
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