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cam lobe inspection
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Just a few quick pics to see how lobes look after 4400 miles.
Lifters have less than a thousand miles due to originals collapsing. Melling SPC-7 and Johnson lifters that are quiet at 1/2 turn preload. Had to remove intake to repaint and reseal, so I wanted to inspect while opportunity presented. Does the lobe wear pattern on nose of lobe appear normal. Ran a day ago to see if all pushrods were spinning ,and a few were slower than rest at idle but then would speed up some at higher rpm. The lifter pic is of one of the ones that were slower and still has raised center and good swirl. If I try to spin pushrods when they are on base of lobe the lifter spins on some and just the plunger inside the lifter on others. Always used either Brad Penn or rotella with ZDDP and filter was clean. Thanks for your thoughts Gerry |
Are you sure the cam was not damaged when the lifters were changed, The one photo of the cam seems like the lobe is wearing bad.
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When you adjusted them, did you make sure the the plunger was not down a little then you went another 1/2 turn? I go 1/4 turn after 0 lash, but you have to watch the lifter close to make sure the plunger is not going down bwfore you tighten it.
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Cam lobe
Watched real close to see when plunger just cam off clip and then 1/2 turn.
This is with 7/16 studs with crimps nuts, fine thread. The original lifters had a few that ticked a hair to much and one was spongy. The new lifters have been very quiet after a few seconds once started. just was looking to see if wear was normal, considering I swapped lifters Last year. I thought if wear mark went clear across nose of cam, lobe was considered worn. Gerry |
If there's any question, cut open a filter and look for magnetic glitter. BTDT
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The bottom of the lifter starts out as a perfect dome, and will start to flatten in the center when things go bad. Putting two bottoms together and holding them up to a light source and rocking them sometimes is the best way to see if the centers are starting to flatten. |
That thing is gone. I see multiple lobes that are not only worn all the way across but also a slight arch to them.
I blew up the cam3 pic and was able to see better. In general, if the lobe is worn across the entire tip/nose of the lobe, it's worn out. There appears to be discoloration from overheating too, suggesting the lifters weren't turning at some point. Maybe post some better pics just to be sure. . |
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Close up of pic 2...
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What was done to break in cam???
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breakin
this cam was installed 5 years ago and breakin was with
rotella and gm eos for 20 min and yes they all pushrods spun at that time. during that time I did have a temp issue which has been resolved. also numerous oil changed through the years and accumulated close to 5000 miles. I will admit I learned ALOT and last year swapped out lifters due to some being spongy. new lifters were installed with paste and run in as a normal breakin. just curiosity caused me to pull valve covers and inspect. will pull all lifters soon and cam. already have a new melling spc-07 on hand and crower cam saver lifters on order. |
You caught it early, before it started really eating up lobes. Clean up should be minimal, should consider yourself lucky! And you get some more garage time too, which is all part of it. I go into the garage sometimes and just stare, it's a mental health thing for me!
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