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did car manufacturers break in flat tappet cams?

Kern Dog said:
I considered having some old lifters cleaned and refaced to use again. I still might for milder builds but for the new cam for the red car, I went with a hydraulic roller to alleviate the anxiety.
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roller cams make my cam break in machine obsolete :blah::blah::blah:
 
steve340 said:
Good question. If they did I guess it would not be the 20-30 minutes at 2000 RPM deal.
It would be interesting to hear from anyone who worked at one of the engine assembly plants.
I did hear once about a factory (I think it was Ford) that turned each the engines with an electric motor.
This allowed them to break the motor in, monitor oil pressure etc.
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I'll ask my neighbor that worked at the Ford assembly plant about that when I see him next Saturday for lunch.
He left today for the Barrett Jackson auction in Palm Beach this weekend.
 
I have a friend who owned an engine machine shop for a few years.
He had a sim test machine which would spin the engine and circulate heated oil.
A perfect way to break in a cam.
 
khryslerkid said:
$60 and a Fram filter :rolleyes:



Back in the '70s we never heard of breaking in a cam. I don't know how many. We removed the radiator, water pump and timing cover, intake and valve covers and threw in a new cam and lifters, sometimes not even new lifters! Several times we did a set of lifters on an old cam. Not one problem.
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I hadn’t really thought about it in a while but back in 70 a friend helped me do a cam swap in my 64 Sport Fury in the dormitory parking lot. When done we simply fired it up and drove. Same when I swapped a Ram Air III cam into my 75 Trans Am a few years later. Just fired it up a drove without any break in.
 
They were run at the engine plant after they were assembled. They weren't run that long, just long enough to make sure nothing came flying off or out of them. They were run again at the assembly plant as the cars were driven off the assembly line to whatever method of shipping the plant used. After that it was up to the new owner to finish the break in.
 
I don’t remember a mention of cam failures until the early 80s when some stories of flat cams in Chevy and Oldsmobile engines from the late 70s on (from memory) started showing up. I think they were blaming poor metallurgy in the camshafts for that.
 
Did the factory run the engines on a test stand before assembly. I know John Deere runs everyone on the dyno to break it in and check for leaks and issues. I know, at a car factory that would be a lot of engines to run.
 
I was going through the MP Engine manual last night, looking at valve spring info. This was a Carol Shelby edition, so probably mid 90’s.
Not a word about cam break in.

There was only a reference to problems due to mismatched (too heavy) springs, lobe scuffing, etc.
 
AR67GTX said:
I don’t remember a mention of cam failures until the early 80s when some stories of flat cams in Chevy and Oldsmobile engines from the late 70s on (from memory) started showing up. I think they were blaming poor metallurgy in the camshafts for that.
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About the time they took ZDDP out of the oil because of catalytic converters.

Yes, excess zinc, specifically in the form of ZDDP (zinc dialkyldithiophosphate), can damage a catalytic converter. While zinc is beneficial for engine lubrication, when it burns in the combustion chamber, it can leave a phosphate coating on the converter's components, reducing its efficiency and potentially causing premature failure, especially in older engines.
 
I bought and installed my first cam, an Sig Erson TQ 20, around the mid 70's in a sbc. Erson cams paperwork , at that time, stressed the need for "cam break in". It simply entailed , DO NOT IDLE, take the engine to a minimum 2200 rpm for 25 minutes. Stated this could be done in the car, on a stand, or on the drag strip. I still follow that process and have not had a failure. Just installed that same type camshaft in a bbc a few weeks ago with no problems.
Many years ago I toured the engine plant where the Harley Davidson v twins were built, and they ran all completed engines on propane prior to loading for shipping. Curious now if auto engines are ran or just spun over these days...
 
toolmanmike said:
they took ZDDP out of the oil because of catalytic converters.
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I'm not saying that's wrong, but how much ZDDP could wind up in a catalytic converter? I mean it's an oil ingredient so it's a small % of the oil by volume, and then the oil would have to be introduced to the combustion chamber, and post-combustion through the exhaust system, and finally into an extremely hot cat.
 
I knew I had seen this picture before. Slant 6 engines being tested at Trenton assembly plant.

hot-testing.jpg
 
qkcuda said:
I knew I had seen this picture before. Slant 6 engines being tested at Trenton assembly plant.

View attachment 1842001
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A whole room full of engines and a total power output of maybe 50 horsepower.. :lol:

Stock valve springs not having a lot of pressure, better oil, better cam metallurgy... All were factors... Hemi's had stout valve springs & were well known for killing cams....
 
My 361 was stamped WT on the pad. Apparently that stands for water test. What determined whether it received a water test? Mine had a repaired defect in one head. Could that have sent it for a water test? More curiosity than anything since those heads are gone now.

516 head void.jpg
 
Breaking in the cam was news to me. Make sure it runs, load the kids and missus, and head to the beach. That is a how a friend did it, but that was a few years ago.
Edelbrock provided good instructions and a bunch of sticky red oil. The whole break in thing got my attention.

I just watched a bunch of guys change an engine in a funny car. They fired it, and ran it for a little bit. Next run will be WOT for about 3.5 seconds.
 
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