I do Not KNOW... but I understand both to be so about GM

I also think a great deal of thought & study has been put into those instructions with marketers' primary consideration of CYA .

 

I think that Summit direction was their legal CYA as well. Face it, some customers there wouldn't know a cam from a crank. LOL

 

My engineer builder told me to use the conventional Driven Breakin in oil with high ZDDP for various reasons at start up plus to seat the rings and to use conventional Driven 15W-50 oil for at least 750 miles before switching to synthetic which I did. This article also documents most ring seating occurs with the 2,000-4,000 RPM pulls but not all ring seating which supports what I did as well. All the reasons for using the conventional oil, breaking in any engine including rollers and the ring seating issue for more than just start up are documented here:

​​​​​​https://www.enginebuildermag.com/201...ly-lube-needs/

Clearly this issue of breakin is not clear cut but there are opinions on both sides of the issues so let's just say, do you research, ask an expert if you can, be aware of the cam manufacturers breakin recommendation, and then use your best judgment to do what you think is best.

You might want to read this as well about how GM DOES recommend a breakin procedure on ALL of its new cars, regardless of engine:

​​​​​​https://www.autoguide.com/auto-news/...s-engine-.html

On my 10C6Z06 I did change the oil and filter at 500 miles with Mobil 1 5W-30 (GM specified) and again at 1,000 miles, this time to Mobil 1 0W-40 European Formula (Not GM specified and used to this day). I drove it easy for the first 500 miles and then progressively moderate, with increasing revs to the LS7, up to the 1,000 mile mark. After the 1,000 mile oil change, it was go for broke.......Runs perfectly today!

Used this exact the moderate driving approach on the 01 Grand Prix with the 3.1 V6 when new and this engine just passed 215,000 miles and uses 0 oil between oil changes. I never have to add any oil between 5,000 miles oil changes...pretty amazing.

None of this changes, my believe/personal experience, and expert recommendation from others that know a lot more than most of us is to breakin a roller cammed motor. Your opinion and experience may differ which is perfectly acceptable......do what you want.

 

The above marine engine article is interesting; maybe it's old-timers syndrome kicking in, but I don't find any reference to cam break-in, or ring-seating, or any break-in?

 

I like the link to the LS V16.

 

I was told by my machinist to use cheap dino oil for inital start and seating of the rings, dump it @ 50 mi and give her hell.
I ran syn rings seated just fine. Just remember to seat those rings quickly. Start, time, ck for leaks then as posters have said run it up then let the engine decel. Give it some throttle dont be afriad of it
If somethigns wrong and is going to break it will do it regardless if you baby it or not. Gradually work your way up in rpm over time no need to be hitting the rev limiter. You can but..

 

wrong link:

https://www.enginebuildermag.com/201...ly-lube-needs/

I fixed the link in the previous post as well...should be good now

 

then feast on these from Mercury Marine … or is it Mercury Automotive? Enjoy!

http://www.mercuryracing.com/sterndr...ngines/1550-2/

http://www.mercuryracing.com/sterndr...0-competition/

http://www.mercuryracing.com/automotive/


FYI, mercury has been moving away from sourcing their power from auto mfgs; hence the above.

 

This leads me back to economy. 50 miles and gone, why waste synthetic? I cannot find a viable reason given for the dino break in, other than cost savings.

Me, I just run VR1 anyhow, so I don't really care. Just curious.

 

Times a changing. Considering they supplied GM with this:

 

My engine builder told me, get it to temp set the timing and drive it. After a few blasts. Change the oil and filter.

I cut the filter open and it was full of lube.

 

This one's engine has my vote today … go nando

http://www.waynetaylorracing.com/gallery/?gid=14993

 

Guys, read the 2 links about marine engine builds and breakin (it's really good) and GM TODAY recommends a 1,500 miles breakin for ALL of its engines, regardless of cylinder number or type.........Then we can discuss debate further.........

​​​​​​
​​​​​​https://www.enginebuildermag.com/201...ly-lube-needs/

​​​​​​
​​​​​​https://www.autoguide.com/auto-news/...s-engine-.html

The evidence is pretty strong refuting some of the previous comments and arguments.............^^^^^^^^^^

 

I asked a retired Cadillac Senior engineer that now builds top fuel engines about breaking in my 17 Silverado. He said change it at 6,000 miles and do nothing. SO, opinions may vary.
He went to MIT, and is no dummy.

 

Fair enough....the point is there is no irrefutable evidence either way to say do not breakin (of course GM says it, though and the marine buildlers article as well, and lots of other documentation but who is counting) or do a breakin. On my engine after $5,000 dollars and my labor, I always will side with caution, especially when it requires VERY little effort and money...just common sense, I guess but........

 

It certainly cannot do harm. Peace of mind for $100

 

 

My machinist is a guy who races on the TV series No Prep Kings and his take is just like Lars and Jebby. Fire it up, make sure the oil pressure is good, set timing and then drive it like you stole it under load, but under redline. Change the filter and press on.

 

Just today was reading about the 2017 Ford Mustang Shelby GT with the Voodoo V8-526 Net HP @ 7,500 RPM, 40,000 mile update and the article in the Feb 2019 issue, clearly states in the body of the Car and Driver article:

"Obeying the 1,000 mile break in period by not revving the engine sky high took painful restraint".

I don't know about you guys, but clearly there is a disconnect here.......................Clearly big manufacturers TODAY do NOT support jumping in modern engines and flooring them...longevity is clearing driving that direction.

My estimate after reading all of the comments and reading the documentation both for and against breakin versus NOT, I have come to the conclusion that not doing a breakin probably is fine most of the time for certain types of engines but every now and again, could be a problem, especially down the line. Mechanical logic does not support the let em rip mentality, but to each his own. Reader beware!

 

I thought all engines were run on N/G or propane to ck before going anywhere