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-   -   cam lobe inspection (https://forums.maxperformanceinc.com/forums/showthread.php?t=767323)

68 Firebird 01-03-2015 07:36 PM

cam lobe inspection
 
4 Attachment(s)
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

JSPONT 01-03-2015 10:12 PM

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.

JSPONT 01-03-2015 10:15 PM

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.

68 Firebird 01-03-2015 10:55 PM

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

jonmachota78 01-04-2015 04:31 PM

If there's any question, cut open a filter and look for magnetic glitter. BTDT

lust4speed 01-05-2015 12:56 AM

Quote:

Originally Posted by 68 Firebird (Post 5332138)
I thought if wear mark went clear across nose of cam, lobe was considered
worn.

Gerry

Correct. Problem is it's a little tough to really see the wear marks in the pictures.

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.

HWYSTR455 01-05-2015 11:30 AM

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.

.

HWYSTR455 01-05-2015 11:34 AM

1 Attachment(s)
Close up of pic 2...

.

77 TRASHCAN 01-05-2015 12:46 PM

What was done to break in cam???

68 Firebird 01-05-2015 12:58 PM

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.

HWYSTR455 01-05-2015 01:14 PM

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!

.

David Jones 01-05-2015 02:18 PM

Quote:

Originally Posted by HWYSTR455 (Post 5332890)
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!

.

Amen and amen. I thought I was the only one.


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