Rat Bastid
Dunamis Metron
Here you go. YMMV but his results are what I’ve seen.
Cam And Lifter Hardness Testing
- Thread starter Rat Bastid
- Start date
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Bobzilla
Well-Known Member
He covered everything. Excellent video. Thanks for posting it.
Now I have no excuses for delaying my project with a solid flat tappet cam. I’ll check it and run it.
Now I have no excuses for delaying my project with a solid flat tappet cam. I’ll check it and run it.
I had to read up on this testing procedure some but have a couple questions. Is the mark permanent and is the part tested scrap or is it usable. Can you bend a cam doing this test and is it usable after testing.
How To Perform Rockwell Hardness Test? - The Constructor
How To Perform Rockwell Hardness Test? - The Constructor
mopowers
Well-Known Member
Why do so many people blame lifter/cam hardness for a failed cam/lifter break-in?
Human nature. Maybe they can’t accept and admit that they f’d up and are at fault. Blame hardness, machining etc. anything but themselves.
Phreakish
Well-Known Member
Rockwell testing makes a dent and then the dent is measured to give a figure. The smaller the dent, the harder the material.
There are more complicated methods, but they cost more. Vickers, or even eddy current systems.
The other thing with most hardness tests is that the specimen has to either be consistent in order to make a meaningful comparison, or the material needs to be thick and flat.
Rockwell and Brinell and others also aren't well suited to surface hardness for case hardened parts or parts with a softer core. It skews the results. Vickers works better for those (microscopic dent), but a vickers tester requires a super high powered microscope and specialty measuring.
There are more complicated methods, but they cost more. Vickers, or even eddy current systems.
The other thing with most hardness tests is that the specimen has to either be consistent in order to make a meaningful comparison, or the material needs to be thick and flat.
Rockwell and Brinell and others also aren't well suited to surface hardness for case hardened parts or parts with a softer core. It skews the results. Vickers works better for those (microscopic dent), but a vickers tester requires a super high powered microscope and specialty measuring.
I know a major issues with wiped cams is guys Dont know how to start a fresh engine. I see guys with dead batteries, distributors 180 out, old fuel or low fuel, trying to prime and engine by turning it over instead of the right way, etc, etc.
Phreakish
Well-Known Member
Or building it and then leaving it for years before firing it. Meanwhile all the assembly lube has fallen into the rusty oil pan.
TT5.9mag
Two atmospheres are better than one
I actually had a custom ground hydraulic roller that failed shortly after I installed it. Called the manufacturer and they asked for it back as well as an oil sample. I sent it and the oil to them and they did some testing. They came back and said the cam missed the hardening process and they cut me a new one and reimbursed me for the engine refresh costs. Made a happy customer. Thanks for the video.
Cal Tonsley
Well-Known Member
I worked for the Australian importer / distributor of Cam Dynamics & Crane Cams for a number of years during the 80s and 90s. The cam failures that were brought to our attention were invariably due to poor run in procedure, wrong oil, no prelube, heavy springs, lack of rotation due to untrue lifter bores & valve train interference.
Regardless, there was always someone who’d insist that they had a cam or lifters that was “soft” or had a lobe that had somehow missed the hardening process (ha ha!) and they’d insist we test to prove their point - in doing this I never, ever, ever saw a cam or lifter that failed a Rockwell test in all my time there!
Regardless, there was always someone who’d insist that they had a cam or lifters that was “soft” or had a lobe that had somehow missed the hardening process (ha ha!) and they’d insist we test to prove their point - in doing this I never, ever, ever saw a cam or lifter that failed a Rockwell test in all my time there!
Thats an expensive special hardness tester he used in the video and yes it is destructive testing, it leaves a dimple in the surface.
What I’m not sure about is the cam cast iron or cast steel? Also not sure of the material of lifters or the manufacturing process. Never have I seen hardness testing done on cast iron although I’m sure its done all the time.
What I’m not sure about is the cam cast iron or cast steel? Also not sure of the material of lifters or the manufacturing process. Never have I seen hardness testing done on cast iron although I’m sure its done all the time.
Mopar44134
Well-Known Member
any videos on showing how to measure taper on the cam?
Rat Bastid
Dunamis Metron
Probably there are videos.
I just put my cams in the lathe between centers and measure the taper with a dial indicator.
I put the lifters in the lathe and sweep the bottom of them to make sure they have a radius on them.
I think he said there should be .002 taper on a good cam. You should be able to pick that up with a set of mics.
Rat Bastid
Dunamis Metron
Yeah, if you are careful you can do it with a micrometer. I have a lather so it’s quicker for me to use that.
There is another recent thread on cam failures that has a link on how to measure.
How far should we have to go to make sure we have a good cam? As I said before I checked rotation and will run break in lube and break in oil and cross my fingers.
ACME SS
Well-Known Member
I agree with this entirely.
I wonder if the non-working parts of a camshaft have the same hardness? It would depend on the process used and perhaps that would be different from manufacture to manufacture. If the entire camshaft is case hardened and THEN it is ground, I would think testing in a non-ground area would indent slightly less than a ground working area, thus giving a higher rockwell. I'd like to just say "buy American" but I'm not sure that is valid anymore...
PRH
Well-Known Member
I had a failed cam hardness checked many years ago.
It was the same hardness everywhere they checked it, which was all over.
Including right in the middle of the worn off lobe.
It was the same hardness everywhere they checked it, which was all over.
Including right in the middle of the worn off lobe.
Like the guy's on the performance TV shows. lol They seem to not waste cams when they run into problems during the initial start.
I've seen them crank and crank on those shows. lol
I've always wondered how much damage, if any, is done when the engine is just cranking. In the old days I think the break in paste got wiped off but the new stuff is supped to cling better.
mopowers
Well-Known Member
Lifter may get locked in position and then a quick death.
RPM helps get the lifters spinning. On the starter, that RPM level isn't high enough and if a groove starts, you're dead.
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