Excessive valvetrain noise checklist
07-28-2004, 09:14 PM
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Excessive valvetrain noise checklist Okay, we just swapped cams from one steep lobed cam to another, and now I've got some ridiculous valvetrain noise.
Both cams were comp cams, so I'm assuming the base circle would be the same. IE, pushrods should be fine.
Springs should have plenty of pressure, they are Crane 99893 dual springs.
The new cam only has more lift on the exhaust side, is it possible that it is tapping the valve covers? This is on a 99 style head.
Everything in this setup dictates that the valvetrain will be loud, but at this point it is more loud than I'm comfortable running it with. There are large valves, stiff springs, and big lift, which would all point to a noisy valvetrain, but it's just plain loud. Also, it was down on power from where it should have been. It made more power with the smaller cam (dyno'd a day before the cam swap), which definitely should not be the case here.
Hope you guys can lend some insight here.
Both cams were comp cams, so I'm assuming the base circle would be the same. IE, pushrods should be fine.
Springs should have plenty of pressure, they are Crane 99893 dual springs.
The new cam only has more lift on the exhaust side, is it possible that it is tapping the valve covers? This is on a 99 style head.
Everything in this setup dictates that the valvetrain will be loud, but at this point it is more loud than I'm comfortable running it with. There are large valves, stiff springs, and big lift, which would all point to a noisy valvetrain, but it's just plain loud. Also, it was down on power from where it should have been. It made more power with the smaller cam (dyno'd a day before the cam swap), which definitely should not be the case here.
Hope you guys can lend some insight here.
