INTERNAL ENGINE MODIFICATIONS Valvetrain |Heads | Strokers | Design | Assembly

Lifter tapping noise mean pushrods are to short?

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Old Apr 9, 2013 | 07:46 PM
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Default Lifter tapping noise mean pushrods are to short?

My neighbor and I "Mainly him" just finished a 2 week cam swap 212/218 .525/.532 114lsa in his 03 4.8. He put in new ls2 trays, ls7 lifters "oiled them over night" P&P 706s milled .025. Stock gm .051 head gaskets stock rockers

We left the timing cover off so we could set #1 rocker at tdc and then tq all the rest at 22ftlbs as wellHe guessed 7.35s would work. I don't think his guess was right seeing as how bad the tapping was/is on all cylinders after 100+ miles.

If the pushrods were to long and too much preload would we hear bad lifter tap? I think we wouldn't hear this^^^ unless they are too short.

The pushrod length checker is being shipped currently

What guesses do yall have? to short or to long?
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Old Apr 9, 2013 | 08:37 PM
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Maybe be to long... You have heads milled .025 and ls7 lifters. If I'm right for just the ls7 lifters need a 7.350 push rod but since the heads are milled he should of order r/p checker from the start...
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Old Apr 10, 2013 | 01:16 PM
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He got the pushrod length checker in the mail this morning. We took the timing cover off and set it to tdc. Piston on exhaust and intake rod length is telling us 7.35s with .6-.7 preload.

So he guessed right on the length. Oil pressure sits around 40-45psi idle arond 50-60psi cruising?

What do yall think is causing the tapping since the pushrods are the right length?
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Old Apr 10, 2013 | 03:36 PM
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get a vid
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Old Apr 11, 2013 | 07:45 PM
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Just a thought but....could you be hearing a slight exhaust leak?...they can sound a lot like valve train noise.
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Old Apr 11, 2013 | 09:04 PM
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I have a very similar setup and I'm running 7.325" pushrods. Mine taps too even after replacing all of the lifters and checking the preload on every valve with a dial indicator. I'm used to the tapping now, only really happens around 1500 rpm.
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Old Apr 12, 2013 | 06:55 PM
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some trash had gotten in the lifters we sprayed them with b12 carb cleaner and ran an engine flush through the system for 10min and changed the oil. Hardly no tapping noise.
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