Noisy Comp Cam 850 lifters

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Mar 6, 2019 | 08:56 PM

DDing

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Noisy Comp Cam 850 lifters

Finished up my cam/head swap on my 6.0. Ended up going with a xr265hr cam and 706/862 heads. Noisy lifters, not horrible on start up (sounds like very minor exhaust leaks). When the engine is hot, lifters sound like metal on metal, maybe a certain few, have preload set at .075. Running mobil1 10w30. Should i run a 10w40 or even 15w50? Noise is extremely bad at 1300-1600 rpms. After 2500rpms, noise is barely noticeable but could be because exhaust is too loud. Need any opinions of running heaviers oils to quiet new noisy lifters. Engine is not new at 139,000 miles.

Mar 6, 2019 | 09:01 PM

qweedqwag

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Do you have the correct length pushrods?

Mar 6, 2019 | 09:22 PM

DDing

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Pushrods are coming up at 7.400. Just used factory pushrods to measeure, come up being exactly what i needed. I’m between 1.5-1.75 turns after no lash to torqued on rocker arm bolt. Within spec as stated by comp cams.

Mar 6, 2019 | 09:42 PM

RockinWs6

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Air in the oil will do this, how is the oil pressure? Could the oring at the oil pump be damaged?

Mar 6, 2019 | 10:02 PM

1FastBrick

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From: JunkYard

Did you change the oil after the job was complete?

Does comp spec .075 Preload for there lifters?

What Springs did you use on the valves?

Mar 6, 2019 | 10:08 PM

DDing

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Quote:

Originally Posted by RockinWs6

Air in the oil will do this, how is the oil pressure? Could the oring at the oil pump be damaged?

only started this noise after cam and lifter swap. Cold idle is 45ish, hot idle 37ish. Oil pressure will go to 75 hot at 6,000

Mar 6, 2019 | 10:11 PM

DDing

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Quote:

Originally Posted by 1FastBrick

Did you change the oil after the job was complete?

Does comp spec .075 Preload for there lifters?

What Springs did you use on the valves?

for these lifters, yes preload is in spec. Bought the cam, lifters, and springs as a kit from comp cams, followed directions thoroughly as stated by comp cams to clean lifters before install, and changed oil

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Mar 7, 2019 | 09:03 AM

patSS/00

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From: AZ

1.75 turns is way more than .075 preload.

Mar 7, 2019 | 09:22 AM

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DDing

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Quote:

Originally Posted by patSS/00

1.75 turns is way more than .075 preload.

one turn past zero lash is 0.050 preload so i’ve been told. Might be off a few thousandth but it’s very close

Mar 7, 2019 | 09:37 AM

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patSS/00

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From: AZ

Quote:

Originally Posted by DDing

one turn past zero lash is 0.050 preload so i’ve been told. Might be off a few thousandth but it’s very close

No it's more like .078. The distance traveled at the pushrod is more than the distance traveled at the bolt. You can visualize this by drawing a simple diagram. The distance traveled at the pushrod is d+(d/1.7), where d is the distance traveled at the bolt. It's a common mistake on here, due to one particular old thread I think.