[llwta76]

Back in '06 I installed the UD 288/296 solid flat that had 145-150# seat pressure and 340# OTN . After consulting with J. Butler I broke that cam in just as indicated above. No problems whatsoever after 6 yrs of use. No real "break-in" oil. Just used 30 weight non detergent oil with about 1400 zinc. New engine that started immediately. FWIW.

[TedRamAirII]

Originally Posted by Half-Inch Stud

I thought the Standard talking point was

" You need to change your oil after the first 300 miles."

that became

" You need to change you oil after the first 500 miles."

..3000 miles.

Here"s your Warranty book , 3000, 6000, and so on. then,

"Warranty void if incorrect oil is used."

Then "Mercedez Bens Oil MUST be used at every oil change interval or Warranty is void."

I dont think "technically" they can do that. MB does not make oil. You have to use oil that meets MB specs. But IF MB states you have to use oil, purchased from MB, according to the Magnuson- Moss Warranty Act, they have to provide it for free. So I'm sure it reads like "must use oil that meets MB approval 229.1" Every car manufacturer does that.

[Tom Vaught]

Originally Posted by TedRamAirII

I dont think "technically" they can do that. MB does not make oil. You have to use oil that meets MB specs. But IF MB states you have to use oil, purchased from MB, according to the Magnuson- Moss Warranty Act, they have to provide it for free. So I'm sure it reads like "must use oil that meets MB approval 229.1" Every car manufacturer does that.

Agree.

Tom V.

[Ben M.]

The engine plant likely did whatever break-in was necessary. By the time the engine got installed in a car on the line it was a "known good" quantity not needing any overly special cam break-in procedure. Way too much time and money invested in assembling the car by then to have a dud engine that hadn't ever been fired that would need to come out and be replaced, not to mention the paperwork nightmare for the guys who tracked that stuff plus warranty issues.

Not that a bad engine couldn't get through the cracks, but I can't imagine them firing the engine for the first time and hoping things went well in a finished car on the line. That's how it's worked in every assembly operation I've been involved with: assemblies like power supplies, engines, transmissions, chambers, optical transmission systems, all of it has been tested before it gets put through assembly and the final assembly process merely checks to make sure everything is operating as a complete package as it should.

[400 Lemans]

Back when i was in auto mechanics class in high school 1978 and 79, GM had shipped our class two 4 barrell 400 pontiac engines. They were complete except for carb, dizzy and accessories and were the 557 type blocks. Still had the intakes, valve covers , timing covers and balancers on them. We never got to tear into of them or anything, mainly they were just there to admire as educational. Always wondered why they were, what we all had assumed were blems. Maybe no oil pressure or something like that. Im sure alot of high schools got stuff like that instead of them being scrapped. I bet there still out there in the shop today.

[Bruce Meyer]

Originally Posted by 400 Lemans

Back when i was in auto mechanics class in high school 1978 and 79, GM had shipped our class two 4 barrell 400 pontiac engines. They were complete except for carb, dizzy and accessories and were the 557 type blocks. Still had the intakes, valve covers , timing covers and balancers on them. We never got to tear into of them or anything, mainly they were just there to admire as educational. Always wondered why they were, what we all had assumed were blems. Maybe no oil pressure or something like that. Im sure alot of high schools got stuff like that instead of them being scrapped. I bet there still out there in the shop today.

Same here. Same time period but there was only 1 of them and nobody was allowed to mess with them either. Just sat there in the shop on display.

[Keith Seymore]

I have to believe it is a combination of "all of the above": mild profiles, zinc in the oil, being run in the test stand at the engine plant before shipment, idle time on the final line, etc.

Originally Posted by dmac

I worked in the Fremont assembly factory filling in for absent people. One day I had the job of driving the car out to the lot.

At the end of the assembly line, the car was started and idled for maybe 4-5(?) minutes on a moving conveyor with various checks being done.. At the end of that rolling conveyor, someone drove it a short distance, maybe 100 feet, and put it through a hard brake. Then I got in and drove it to the lot for loading onto transport or train. This was in the late 70s. Not all cars started of course.

Not having a car start at the end of the line is a major emotional event. We had little pusher tractors ("mules") that were used to push a "dead head" off the end of the line and into a specific repair bay, hopefully without having to shut the final line down momentarily. The assembly plant guys are very testy about that, especially if you are a visiting engineer and if there is some way they can possibly construe that you were responsible for the down time.

When I was a production supervisor we all had to take a turn "working repair out back". So we would run 8 or 10 hours production, and then go to the repair area and supervise for another 2 or 3 hours over repair. We would invite any of the assemblers to come out back and drive, if they wanted the overtime (I had two groups of people that worked for me: those that would work two days a week if they could get by with it, and those that would kill a man on my behalf if I would pay them 1/2 OT through lunch).

Originally Posted by dmac

That whole area was at the opposite end of the plant from my normal area, maybe 1/2 mile or more. I still 30+ years later occasionally have strange dreams about how big the plant was where I get lost looking for the cafeteria or a restroom. Never really got lost.

I think of that often. Some of the assembly plants here (like the Packard facility, or Ford's Highland Park plant and "the Rouge") are literally small cities. Can you imagine just getting off the boat, not speaking English, and having to find your way inside the right area of the plant to get your work done?

K

[GRX]

Wager on Molybdenum disulfide.

[dmac]

Just thinking that the engine doesn't have to actually 'run' to break in the cam, just 'spun.' Wouldn't even need an intake, fuel system, or an exhaust system. That is something I could see a factory doing if they felt a break-in period was needed.

[77 TRASHCAN]

LOL, we need someone(s) that worked in an engine plant....

I'm betting there was possibly nothing applied to cam. There was likely folks that experimented with breaking procedures in those days. The test fire may have proved to be sufficient. Just a thought, and EOS in the oil...
Typically the cam/lifter relationship only has to last mostly just past one year. Likely an easy deal.
The number 7 exh. lobe on my T/A engine started going flat around 70,000. Way past the extended warranty I signed up for.....I took great care of my car.

[dataway]

I'm still thinking that factory lobe profiles took into account lack of break-in. Probably not a good decision to create a factory cam that performs the way you want but takes 20 minutes on the line to break in. As per usual, a compromise. Those stupid engineers were probably pretty good at finding something that was economical to produce, easy to manufacture, and would get through the warranty period.

I'm yet to get over the 100,000 mile + engine I tore apart and it still ran like a bear, and most people here (myself included) would have said it should have failed 90,000 miles before it did based on the way it appeared to be put together. Amazing how good the factory was at throwing these engines together and still have them run for 10 years of abuse with only minimal maintenance.

[#1965GTO]

Several years ago I saw TV show about how Chevrolets were built and assembled. The part about the engine line was very good. They showed it from rare materials to the finished product. During assembly the engine they showed was initially timed with #1 at TDC and the distributor points set at the proper gap for that phase of the engine cycle. With the carburetor in place they install each engine on a test stand, this only took a matter of seconds. A flexible hose, like a dryer vent, attached to the carburetor and the engine was started. The hose had the proper mixture of natural gas to test run the engines and have no gasoline hazard for the remainder of assembly line. They monitored the oil pressure, checked for leaks and more precisely set the timing all the while the engine was under load of dyno. This run time was about a minute there was no coolant used on the test stand. Although not ideal that was the process shown at the time. I'm sure the good old zinc content of the oil used along with EOS worked fine for 99% of the application.

[commanderpilot]

Can't speak for the engine build line as far as run time went, but do know that after installation in the vehicle the run time was less than two minutes in the assembly factory. It involved about one minute to check start, settings, leaks etc and about one minute on the bumpy road rollers. It then took a pedal to the metal trip to the shipping lot and was parked there till loaded on truck or train transports.. None of this time was done for break-in purposes, but rather as a perfunctory engine and chassis test which had to match production line speeds.
They were building 60/hour and had two end-of-line bumpy road rollers, hence the two minutes maximum.

[dmac]

Originally Posted by commanderpilot

Can't speak for the engine build line as far as run time went, but do know that after installation in the vehicle the run time was less than two minutes in the assembly factory. It involved about one minute to check start, settings, leaks etc and about one minute on the bumpy road rollers. It then took a pedal to the metal trip to the shipping lot and was parked there till loaded on truck or train transports.. None of this time was done for break-in purposes, but rather as a perfunctory engine and chassis test which had to match production line speeds.
They were building 60/hour and had two end-of-line bumpy road rollers, hence the two minutes maximum.

I recall a little longer time running- maybe 5 minutes from start-up through the check line. Seems like at least 4-5 vehicles, and maybe 6-7 or more meaning at least 5 minutes of run time before it got through. Then the engine was stopped and restarted right before being driven off. But that could have changed in the last 35+ years!!!!!!!!

[Cliff R]

I've been building engines since the 1970's and have had ZERO cam lobe failures with flat camshafts. Even after we started seeing a LOT of failures in the early 2000's after lifter production went to Mexico and "off-shore". Reason why is that I have NEVER once used any Delphi or other "no-name" lifters. It's mostly by accident than anything else as we went to roller cams here in 2004 and the very few flat cam engines we've done have used either Rhoads or genuine Johnson (Hi-Lift) lifters in them.

I also do NOT use the liquid break in lubricants, it doesn't stay in place long and most of these builds sit for some time before we make it to the dyno with them. Instead I use moly-grease, just a dab on the bottom of each lifter and smear each lobe all the way around with a small amount.

To this day I firmly believe that nearly all of the cam lobe failures we've seen in the past 10 years or so that get blamed on oil, break-in, break-in spring pressure/type of lube used, etc, is ALL from using low quality lifters with a low nickel content and poorly machined/finished on the bottom.

What else helps is that don't use "aggressive" lobe profiles either. Most flat cams have been from CMC sold as generic grinds or we've used Crower cams. Comp does all of our roller stuff for us, but we NEVER let them choose anything, they'll grind the cam on a tight LSA and not enough seat timing for what you are doing every single time!........Cliff

[Keith Seymore]

Originally Posted by commanderpilot

Can't speak for the engine build line as far as run time went, but do know that after installation in the vehicle the run time was less than two minutes in the assembly factory. It involved about one minute to check start, settings, leaks etc and about one minute on the bumpy road rollers. It then took a pedal to the metal trip to the shipping lot and was parked there till loaded on truck or train transports.. None of this time was done for break-in purposes, but rather as a perfunctory engine and chassis test which had to match production line speeds.
They were building 60/hour and had two end-of-line bumpy road rollers, hence the two minutes maximum.

Originally Posted by dmac

I recall a little longer time running- maybe 5 minutes from start-up through the check line. Seems like at least 4-5 vehicles, and maybe 6-7 or more meaning at least 5 minutes of run time before it got through. Then the engine was stopped and restarted right before being driven off. But that could have changed in the last 35+ years!!!!!!!!

Any of the GM vehicle assembly plants that I have worked in (Flint, Pontiac, Ft Wayne, Oshawa, Janesville, St Louis, Arlington, Silao, Wentzville, Detroit-Hamtramck, and Mishawaka) we let them run probably 5 minutes or more at the end of the final line, before roll test.

K