Seem to remember something about running them on air to check and break in? Were they all broken in when installed on assembly line? You just see them idle them away....would not be good if actual first start.
When I put my Comp Cam in 1983 I did not know about running engine to 2500 rpm for 20 minutes I let it idle may have revved it up some but knew nothing about the 2000 rpm rule lol it never screwed up either Oil was probably so good then probably didn't need much break in I would guess or the cams were coated to hold up? Unless they run those motors at the plant before they go out after all rings have to be broke in somewhat wouldn't you think?
Those stock engines with those nice lifters..correctly ground cams...little spring psi...and the good dinosaur fat oil....I'm sure they never thought twice about it....or even had heard about cam failures then
I had a sbc 400 in which I installed a not-two-radical Edelbrock hydraulic cam (two lobes of the original cam were toast). I pre-lubed it with the engine oil that I was going to use, then before I installed the lifters I dumped a bit of Sticky Tacky Poo (STP) down each lifter bore to lubricate the lobes. After I got the engine back together I just drove it normally, although I kept my foot out of it far a few days.
I believe the OP wants to know how Buick did it at the factory? I’m sure curious also. I bet Denny Manners will know.
i worked at a big shop that rebuild navistar diesl eng,we regroung old cams and used them in the rebuilt engs mostly 6,9 engs,always ranem on one of 6 dynos only to check for leaks andmake sure the correct power was there,i think the reground cames were to spec as a cam that way broke in,they also brazed cracked heads,they would put them in to a certain heat and braze em,about 90% of the work was for 6.9 and7.3 navistars for u-hall
This and I do believe they ran them all on engine stands. Not a Buick engine factory, but I've seen pictures like these and a few video's out there of different engine makes, and all have run stands that run the engines a bit at the end of the engine assembly line.
I wasn't around in the late 60s so I can't speak for what Buick did back then. But I have gone to several engine plants in the 90 - 00s. They run each engine, but it's more about to check if it's been built correctly. Not really any kind of break in. So I would say hugger is most likely right. For all the reasons he stated.
Way back when the lifters & cam lobes had a deeper hardening of their surfaces than they do today. I believe the hardness was 62 on the c-scale. Tom T.
I believe that's what Oldsmobile did back then. They powered the motors externally for a length of time and checked for abnormalities.
Majority of factory cams weren't high lift cams and the valve springs didn't need to be very high psi. Probably didn't take long to break in.
I visited a Buick assembly plant in Deleware in the late 60s. They started cars at the end of the assembly line, drove it on to a wheel dyno, floored it and held it there for 2 minutes. If it survived it went on the truck, if not, it went somewhere else. This is why not all cars got out of the plant numbers matching. The engines may have already been broken-in by then. Out tour guide was a good looking lady wearing a mini skirt. There was guy in a pit putting body bolts on, he was so busy looking up her skirt that 3 Buicks went down the line with no body bolts.
My dad was a Buick salesmaster and won a trip to Flint in1972, he said they ran the engines on air, his demonstrator at the time was a really early build 72 stage 1. That car kicked ass all over town. My brother bought it in 85’ and put it in a ditch
