Noise after top end install
Racer
Joined: Mar 2018
Posts: 395
Likes: 52
From: wilmington Ma
Something was hitting something and wore some clearance noise gone ,
As far as breaking in a ft cam I do it with higher rpms like described, but I agree with the statement we didn't do that before , in the early 80' s I was a tech and did all the cams and lifters I never broke any in , I just swapped out all the parts set timing and see ya ! Never had a come back cam related , I remember scrapping all the sludge from the heads and lifter valleys using a shop vac. I think today they just use chit metal.
As far as breaking in a ft cam I do it with higher rpms like described, but I agree with the statement we didn't do that before , in the early 80' s I was a tech and did all the cams and lifters I never broke any in , I just swapped out all the parts set timing and see ya ! Never had a come back cam related , I remember scrapping all the sludge from the heads and lifter valleys using a shop vac. I think today they just use chit metal.
Drifting
Joined: Jun 2025
Posts: 1,731
Likes: 600
Until a relatively short recent history, ALL motor oil had relatively high concentrations of both Phosphorus and Zinc wear package; those hi-levels Long Gone from common motor oils.
That P & Zn protection in everyday common oil IS what prevented routine flat tappet cam n lifter failures.
Similarly, Leaded gasoline provided valve & valve seat erosion protections. Also, gone the way of the buggy whip.
That P & Zn protection in everyday common oil IS what prevented routine flat tappet cam n lifter failures.
Similarly, Leaded gasoline provided valve & valve seat erosion protections. Also, gone the way of the buggy whip.
Race Director
Joined: Mar 2016
Posts: 14,406
Likes: 8,212
From: Napa Valley California
I believe the flat tappet cams and lifters were produced with higher quality steel back in the day so there were no issues.
Today the quality of steel is what leads to more component failures.
We never worried about distributor gears or fuel pump shafts either, but today we have to be careful about the products we mix and match.
To the OP.
I would drain the oil, drop a magnet into the bottom of your collection pan and see if you find any metallic material sitting on the bottom.
I would also pick up an oil filter cutting tool, cut open the filter and see if there are any metallic pieces trapped in the filter.
I would also pull your valve covers and check everything in the top end especially for any weird wear marks on the push rods, bent push rods and make sure all push rods are set correctly in the rockers.
Double check the springs and valve adjustment.
There may be nothing wrong, but better to find any issues now sitting in your garage rather than cruising down the road at a later date.
Today the quality of steel is what leads to more component failures.
We never worried about distributor gears or fuel pump shafts either, but today we have to be careful about the products we mix and match.
To the OP.
I would drain the oil, drop a magnet into the bottom of your collection pan and see if you find any metallic material sitting on the bottom.
I would also pick up an oil filter cutting tool, cut open the filter and see if there are any metallic pieces trapped in the filter.
I would also pull your valve covers and check everything in the top end especially for any weird wear marks on the push rods, bent push rods and make sure all push rods are set correctly in the rockers.
Double check the springs and valve adjustment.
There may be nothing wrong, but better to find any issues now sitting in your garage rather than cruising down the road at a later date.
Drifting
Joined: Jun 2025
Posts: 1,731
Likes: 600
our OE chevy flat tappet cams are not steel; they've been made of cast iron for over a century. CWC has been and continues as GM's primary supplier of flat tappet cores. Look between your OE chevy flat tappet camshafts' lobes for CWC as in link below.
Campbell, Wyant & Cannon (CWC)
https://www.kautex.com/en/mobility/cwc-textron-castings
I do not dispute metal quality has suffered; as well as has oils' wear packages. Also, for the past Forty-some years, GM has shied away from cast iron flat tappet cams; superseded by near-exclusivity of mild billet steel roller cams. Seems government agencies'/bureaus' mandates precipitated those design changes.
Also, camshaft cores known as Austempered Ductile Iron (ADI) or Selectively Austempered Ductile Iron (SADI) are made of Cast Iron.
Campbell, Wyant & Cannon (CWC)
https://www.kautex.com/en/mobility/cwc-textron-castings
I do not dispute metal quality has suffered; as well as has oils' wear packages. Also, for the past Forty-some years, GM has shied away from cast iron flat tappet cams; superseded by near-exclusivity of mild billet steel roller cams. Seems government agencies'/bureaus' mandates precipitated those design changes.
Also, camshaft cores known as Austempered Ductile Iron (ADI) or Selectively Austempered Ductile Iron (SADI) are made of Cast Iron.
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2023 C3 of the Year Finalist - Modified
I hope you don’t let the argumentativeness of one person ruin your day.
Drifting
Joined: Jun 2025
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Advanced
Joined: Oct 2024
Posts: 81
Likes: 22
From: Michigan
I think we each have different ways of doing the same things. I started at a new dealer and the Tech behind me and I were each tearing apart intakes on V6 Astro vans to check for cracked blocks just under he head surfaces. I had my parts lined up on the table in order to go back in the same position as before. Jon just threw everything into one box. He said, " I can't stand people who line up their parts in a row on the table It makes me sick!". I said "Fine. Just keep it off my table". We've been friends ever since and haven't changed our ways.
